Discover User Guide

Encom Discover User Guide

discoverIntegrated GIS for the GeosciencesVersion 11.0 User Guide

© Pitney Bowes Software Pty Ltd, 2009.

Encom Discover is developed and supported by Pitney Bowes Software Pty Ltd, a company incorporatedin the State of New South Wales, Australia.

Asia-Pacifi c/AustraliaLevel 7, 1 Elizabeth PlazaNorth Sydney NSW 2060 AustraliaT +61 2 9437 6255 F +61 2 9439 1773

Discover SupportLevel 1/469 Glen Huntly RoadElsternwick VIC 3185 AustraliaT +61 3 9523 0033 F +61 3 9523 2296

[email protected]

Discover Release HistoryVersion 1.0 December 1994Version 1.1 February 1995Version 1.2 September 1995Version 2.0 August 1996Version 2.1 November 1997Version 3.0 February 1999Version 4.0 July 2001Version 5.0 June 2002

Version 6.0 October 2003Version 6.1 April 2004Version 7.0 May 2005Version 8.0 June 2006Version 8.1 February 2007Version 9.0 July 2007Version 10.0 June 2008Version 11.0 June 2009

Version 11.0 Integrated GIS for the Geosciencesdiscover

Discover 11.0 requires a current installation of MapInfo Professional 8.5 or later with Windows® Vista,Windows® XP Professional (Service Pack 2) or Windows® 2000 (Service Pack 4) operating system.

User Guide

Table of Contents i

1 Managing the User Interface and Workspaces..................................... 1

Discover Menus......................................................................................... 1Discover Toolbars ..................................................................................... 2Using the Discover Command Search Tool .............................................. 3Organising Your MapBasic Tools.............................................................. 4Managing Your Workspaces ..................................................................... 6

Favourite Workspaces ......................................................................... 7Checking and Modifying Table Locations in a Workspace................... 8Preparing a Workspace for Sharing and Archiving ............................ 10Fixing Problems in a Workspace........................................................ 11

2 Map Window Controls........................................................................... 15

Map View Settings .................................................................................. 15Setting the Default Map View............................................................. 15Saving and Restoring the Mapper State ............................................ 16Saving and Applying View Settings.................................................... 16

Map Projections ...................................................................................... 18Saving and Applying Map Projections................................................ 18Displaying Mapper Projection Details ................................................ 21

Displaying Map Coordinates, Distances and Bearings ........................... 21Display a Dynamic Scale Bar Window .................................................... 23Add a Dynamic Map Grid to a Map Window ........................................... 24Window Size and Zoom Controls ............................................................ 25

Fit the Map Window to the Selected Object ....................................... 25Zoom to the Extents of the Selected Object....................................... 26

Linking Map Windows ............................................................................. 26Show Cursor Position in Linked Windows.......................................... 28Matching the Sizes of Linked Windows.............................................. 30

3 Importing and Exporting....................................................................... 31

Importing Data with MapInfo and Discover ............................................. 31Import Formats Supported by Discover................................................... 32Tabular and Vector Data ......................................................................... 34

acQuire............................................................................................... 35ASCII Data ......................................................................................... 36

Supported ASCII File Formats ...................................................... 39ASCII Import Options .................................................................... 41Line Number Record ..................................................................... 41Ignored Records ........................................................................... 42Ignored Characters ....................................................................... 42Save and Reload ASCII Template ................................................ 42

Table of Contents

ii Encom Discover User Guide

Datamine ........................................................................................... 42Importing Datamine Points ........................................................... 43Importing Datamine Perimeters and Strings................................. 44Exporting to Datamine .................................................................. 45

DataShed........................................................................................... 46DataSight ........................................................................................... 46

Server Authentication ................................................................... 47Access Methods ........................................................................... 47Prerequisites for Using the DataSight Import Tool ....................... 48Working with the DataSight Import Tool ....................................... 48

DXF.................................................................................................... 50DXF Import ................................................................................... 51Export Contours to 3D DXF ......................................................... 53Export Digitized Boundaries to 3D DXF........................................ 53

Gemcom ............................................................................................ 54Geosoft .............................................................................................. 55ioGAS ................................................................................................ 57LIDAR LAS ........................................................................................ 58MicroMine .......................................................................................... 59MineSight........................................................................................... 60

Importing MineSight Points and Polylines .................................... 60Exporting to MineSight ................................................................. 61

Surpac ............................................................................................... 62Importing Surpac Strings .............................................................. 62Exporting to Surpac ...................................................................... 64

Vulcan................................................................................................ 65Importing Points and Polylines ..................................................... 65Exporting to Vulcan ...................................................................... 66

Import, Reproject and Convert Vector Files....................................... 66Raster Imagery ....................................................................................... 69

Rectifying Raster Images................................................................... 69ECW/JPEG2000 ................................................................................ 69Encom EGB ....................................................................................... 72

Importing an EGB Image .............................................................. 72Exporting as an EGB Image ......................................................... 73Saving a Map Window as a Registered Raster Image ................. 74

Surface Grids.......................................................................................... 74ASCII Grid.......................................................................................... 75

X Y Z values file format ................................................................ 77Z values only file format................................................................ 77

HGT Grid ........................................................................................... 79Alternative Grid Import Tools ............................................................. 79

BIL Grid ........................................................................................ 81ER Mapper Grid............................................................................ 82ESRI ASCII Grid ........................................................................... 85Geosoft Grid ................................................................................. 86Minex Grid .................................................................................... 87

Table of Contents iii

Surfer Grid .................................................................................... 89Vertical Mapper Grid ..................................................................... 90USGS DEM Grid ........................................................................... 91

Convert v2.1 Grids ............................................................................ 94Toggle Support for Vertical Mapper Grid ........................................... 94Export Grid to ASCII File.................................................................... 95Export Grid ........................................................................................ 95

Drillholes ................................................................................................. 96Discover Drillhole Projects ................................................................. 96gINT ................................................................................................... 97WinLoG .............................................................................................. 99

4 Working with Tables ........................................................................... 103

Opening and Closing Tables ................................................................. 103Opening Favourite Tables................................................................ 103Opening Multiple Tables .................................................................. 106Closing All Tables ............................................................................ 107

Refreshing Tables with Database Connections .................................... 109Searching and Replacing Text in Tables............................................... 111Selecting Table Records ....................................................................... 112

Select by Group ............................................................................... 112Sorting Tables ....................................................................................... 114Changing the Map Bounds of a Mappable Table .................................. 116Splitting Tables...................................................................................... 117Digitizing and Data Entry....................................................................... 120

Setting Increments and Constant Values......................................... 122Manual Data Entry ........................................................................... 123Automated Data Entry...................................................................... 124

Adding Unique Identifiers to Table Records.......................................... 125Updating Multiple Columns ................................................................... 126Working with Multiple Tables................................................................. 129

Packing Multiple Tables ................................................................... 129Appending Multiple Tables............................................................... 130Importing Multiple MID/MIF Files ..................................................... 130Exporting Multiple MID/MIF Files ..................................................... 131Reprojecting Multiple Tables............................................................ 131Multi-table, Multi-field Editing ........................................................... 131

Field Display ............................................................................... 132Field Editing ................................................................................ 133

5 Data Processing and Statistics.......................................................... 137

Pre-processing and Cleaning Data ....................................................... 137Classifying Data .................................................................................... 138

Classifying Data by Colour, Size, and Symbol................................. 138

iv Encom Discover User Guide

Multi-field Classification ................................................................... 141Trivariate Point Classification .......................................................... 142

Setting Point Styles .................................................................... 144Displaying a Point Style Legend................................................. 145Null Values ................................................................................. 145

Normalizing or Levelling Data............................................................... 146Levelling Operations ........................................................................ 147

Computing Summary Statistics............................................................. 150Computing a Correlation Matrix ............................................................ 153

6 Coordinates and Projections............................................................. 155

Calculating Distances Between Points in Separate Tables .................. 155Displaying Cursor Coordinates in a Map Window................................. 157Updating Coordinates ........................................................................... 157

Coordinate Update Mode................................................................. 158Coordinate Transformations ................................................................. 158

Plane Transformation ...................................................................... 160Affine Transformation ...................................................................... 162

Creating a Custom Affine Projection........................................... 166Using the custom affine projection in MapInfo............................ 168

Reprojecting Coordinates ..................................................................... 168Reprojecting a Table........................................................................ 168Reprojecting Multiple Tables ........................................................... 170

Generating Traverse Lines and Peg Coordinates................................. 171Local Grid Definition Options ........................................................... 174Grid Line Parameters....................................................................... 175Grid Parameters .............................................................................. 175Output Options................................................................................. 176Advanced Options ........................................................................... 177

7 Managing Maps and Layers............................................................... 179

Opening and Closing the ELC Window................................................. 179ELC Window Controls........................................................................... 180Configuring the ELC ............................................................................. 182Using the ELC....................................................................................... 183

Shortcut Menus................................................................................ 183Layer Aliases ........................................................................................ 184Layer Groups ........................................................................................ 186

Limitations of the Grouped View...................................................... 189

8 Working with Map Objects ................................................................. 191

Objects and Layers............................................................................... 191

Table of Contents v

Creating Objects from a Table .............................................................. 192Row Delimited Polylines................................................................... 193Column Delimited Polylines ............................................................. 194Line on One Row Polylines .............................................................. 195XYZ Grid .......................................................................................... 196

Creating and Editing Objects from the Keyboard .................................. 196Selecting the Object Type ................................................................ 196Draw a Point..................................................................................... 197Draw a Line ...................................................................................... 198Draw a Polyline/Polygon .................................................................. 199

Enter Nodes by Coordinates....................................................... 199Enter Nodes by Distance, Bearing .............................................. 199

Draw an Arc, Ellipse or Rectangle ................................................... 200Edit Node Coordinates ..................................................................... 201

Selecting Objects .................................................................................. 201Select by Proximity........................................................................... 201Select All Objects in Editable Layer ................................................. 203Select by Graphical Style ................................................................. 204

Copying, Moving and Transforming Objects ......................................... 205Offsetting Copies of an Object ......................................................... 206Moving, Scaling and Rotating Objects ............................................. 207Aligning Objects ............................................................................... 209

Manipulating Lines, Polylines and Polygons ......................................... 211Smoothing ........................................................................................ 212Thinning ........................................................................................... 213

Thin Polyline by Node Number ................................................... 213Thin Polyline by Node Position ................................................... 214

Cutting.............................................................................................. 215Joining.............................................................................................. 215Inserting Nodes ................................................................................ 217Changing Line Direction................................................................... 220Creating Donut Polygons ................................................................. 220Clipping ............................................................................................ 222Splitting Multiple Polylines and Polygons......................................... 223

Using Polyline and Polygon Attributes .................................................. 224Assigning Values to and from Polygons........................................... 224

Contents to Container ................................................................. 225Container to Contents ................................................................. 226

Assigning Values to Polygons from a Grid....................................... 226Calculating Line Orientation ............................................................. 226Extracting Nodes.............................................................................. 227Calculating Area Change ................................................................. 228

Conditioning and Converting Linework into Polygons ........................... 230PolyBuilder Dialog............................................................................ 232

Linework Layer............................................................................ 233Text Layer ................................................................................... 233Menus ......................................................................................... 233

vi Encom Discover User Guide

PolyBuilder Toolbar .................................................................... 234Preferences ..................................................................................... 235

Linework ..................................................................................... 236Polygons..................................................................................... 237Field Information......................................................................... 237

Digitize Linework.............................................................................. 237Check Linework ............................................................................... 241

Error Flags.................................................................................. 243Correct Linework.............................................................................. 244

Extend and Break Linework........................................................ 244Fix Linework ............................................................................... 246

Create Polygons .............................................................................. 251Polygon Errors ............................................................................ 253Donut Polygons .......................................................................... 254Attribute Polygons with Text ....................................................... 254

Additional Linework Utilities ............................................................. 256Break Linework........................................................................... 257Join Linework.............................................................................. 258Filter Linework ............................................................................ 259

Colouring Map Objects ......................................................................... 259Colour Map Objects from Look-up Tables ....................................... 260

Creating Colour Look-up Tables................................................. 260Create a Colour Table from an Existing Map.............................. 262Create a Colour Table from a Thematic Map ............................. 264Edit a Colour Table ..................................................................... 265Apply a Colour Map to Map Objects ........................................... 266Create a Legend from a Colour Table ........................................ 268Export a Colour Map to Discover Mobile .................................... 269

Saving and Applying Thematic Map Settings .................................. 269Save Thematic Map Setting in MapInfo...................................... 269Save Thematic Map Setting with Auto-Shade ............................ 270Apply Auto-Shade Setting to Table ............................................ 271Use Other Auto-Shade Files....................................................... 271Use Auto-Shade with Other Discover Functions ........................ 271

Colour Map Objects by RGB Values ............................................... 272Formatting Vector Objects .................................................................... 274Cloning Object Styles ........................................................................... 275Linking Objects to External Documents ................................................ 278

Setting Up Hotlinks .......................................................................... 279Creating a Hotlink ............................................................................ 280Opening Linked Documents ............................................................ 282

9 Map Making ......................................................................................... 283

Creating Scaled Maps .......................................................................... 283Create Scaled Output Map .............................................................. 284

Table of Contents vii

Map Scale and Map Size ............................................................ 285Frame Setup ............................................................................... 285Configure Frame Settings ........................................................... 286Position Scaled Output Map ....................................................... 288Accept Map Position ................................................................... 290Configure Map Grid Settings....................................................... 290Enter Scaled Output Title Block Details ...................................... 290

Modifying Scaled Output Layout ...................................................... 291Preserving the Linked Map Window's Scale/Extents ....................... 291Printing a Scaled Output Layout ...................................................... 292Creating Additional Scaled Output Maps ......................................... 292Scaled Output and Standard Map Sheets........................................ 293Scaled Output Hints ......................................................................... 294Exit Scaled Output ........................................................................... 295

Add a Map Grid ..................................................................................... 296Map Grid Projection ......................................................................... 297Grid Spacing .................................................................................... 298Map Grid Styles................................................................................ 298Save and Overlay Map Grids ........................................................... 300

Add a Scaled Frame to the Layout........................................................ 300Add a Title Block and Scale Bar............................................................ 301

Scale Bars........................................................................................ 302Title Block and Scale Bar Options.................................................... 303

Title Block Options ...................................................................... 304Scale Bar Options ....................................................................... 304Layout Templates ....................................................................... 304

Using Object Styles ............................................................................... 305Apply Styles from List....................................................................... 305Maintain Styles Library..................................................................... 307

Edit Map Object Style Entry ........................................................ 307Add or Delete Map Object Style Entry ........................................ 307

Add a Map Legend................................................................................ 307Legend Tables and Columns ........................................................... 308Legend Style .................................................................................... 310Legend Order ................................................................................... 310

Add and Format Text and Labels .......................................................... 312Adding Titles to Frames ................................................................... 313Adding Text Labels .......................................................................... 313

Construct Text Label Expression ................................................ 314Customize Text Label Style ........................................................ 315

Formatting Text ................................................................................ 315Modifying MapInfo Label Angles ...................................................... 317Updating Labels and Tables ............................................................ 317

Update Text Labels from Table................................................... 318Update Table from Text Labels................................................... 318Recolour Text Labels with a Pattern ........................................... 318

Adding Line and Point Labels .......................................................... 318

viii Encom Discover User Guide

Apply SeeThru Shading........................................................................ 321Create SeeThru Shade Pattern ....................................................... 322

SeeThru Shading Pattern Type .................................................. 322SeeThru Shading Pattern Density and Orientation..................... 323

SeeThru Shade Pattern Library ....................................................... 323Apply Geological Line Styles and Annotations ..................................... 324

Structure Line Styles........................................................................ 326

10 Capturing Maps as Images and Movies............................................ 329

Saving a Map Window as a Registered Raster Image ......................... 329Making Movies and Animations from Map Windows ............................ 331

Create Animation File ...................................................................... 332Play Animation File .......................................................................... 333Edit Animation File........................................................................... 335Create Movie File............................................................................. 336

AVI Movie File Format ................................................................ 336

11 Viewing Data in Three Dimensions ................................................... 339

12 Graphs and Profiles............................................................................ 341

General Purpose Graphs...................................................................... 341Getting Started with GraphMap ....................................................... 343

Time-Series Graphs.............................................................................. 347Temporal Data Format..................................................................... 348Setting Up Temporal Trends Graphs............................................... 349Creating Temporal Trends Graphs .................................................. 349Querying Temporal Trends Graphs ................................................. 352

Surface Grid Profiles............................................................................. 352Stacked Profiles.................................................................................... 352

13 Using the GraphMap Tool .................................................................. 357

Starting GraphMap ............................................................................... 357GraphMap Menus and Toolbars ........................................................... 358

File Menu ......................................................................................... 358Quick Access Toolbar...................................................................... 359Menu Tabs....................................................................................... 361Sidebar Windows............................................................................. 363

Creating Graphs ................................................................................... 366Graph Builder................................................................................... 367Axis/Field Assignments.................................................................... 367Graph Types .................................................................................... 371Selecting Data ................................................................................. 374

Table of Contents ix

Preconditioning Data ............................................................................. 376Creating Derived Columns .................................................................... 378Viewing Data Values ............................................................................. 381Arranging and Modifying Graph Displays.............................................. 383

Closing Graphs ................................................................................ 383Hide and Show Windows ................................................................. 384Arranging Graphs............................................................................. 386Adding a Graph to a Map Window ................................................... 388Zoom, Pan and Rotation .................................................................. 389Axis, Scale, Background, and Other Display Options ...................... 390Current Graph Controls.................................................................... 390

Selecting Data in Graphs ...................................................................... 391Saving Selections............................................................................. 392Viewing Selections in MapInfo and GraphMap ................................ 393Displaying Object Information .......................................................... 393Clearing Selections .......................................................................... 393Creating Permanent Selection Regions ........................................... 394

Multi-Table Relationships ...................................................................... 396GeoLocated Graphs.............................................................................. 398

Define Graph Type........................................................................... 399Create GeoLocated Graphs Wizard................................................. 401View GeoLocated Graphs ................................................................ 402Global Options ................................................................................. 404

Displaying Statistics .............................................................................. 405Changing the Style of Graph Objects.................................................... 406

Colour............................................................................................... 407Advanced Colour Options ........................................................... 407

Size .................................................................................................. 410Advanced Sizing Options............................................................ 410

Symbol ............................................................................................. 411Visibility ............................................................................................ 412

Advanced Visibility Options......................................................... 412Load and Save Styles from Legend ................................................. 413Displaying Legends.......................................................................... 414Apply RGB Colours from Table........................................................ 414

GraphMap Settings ............................................................................... 415Mouse Buttons Settings ................................................................... 415Global Settings................................................................................. 415Reset Layout .................................................................................... 416Graph Window Settings ................................................................... 416

14 Working with Images .......................................................................... 417

Images and RAM Size........................................................................... 417Registering and Rectifying Raster Images............................................ 418

Image Selection ............................................................................... 419

x Encom Discover User Guide

Using the Rectify Image tool............................................................ 420Choose Image Projection ........................................................... 421Add (or edit) Map Control Points ................................................ 422Save Control Points .................................................................... 423View Ground Control Points ....................................................... 423Synchronise Modified Ground Control Points to Map/Image Control Point Locations ........................................................................... 423Synchronise Modified Map/Image Control Point Locations to Ground Control Points ............................................................................. 423Rectify......................................................................................... 424

Rectify Image Options ..................................................................... 424Transformation Methods.................................................................. 425

Reprojecting an Image.......................................................................... 426Image Tool ............................................................................................ 428Displaying Image Properties ................................................................. 429Enhancing an Image............................................................................. 430Applying Image Filters .......................................................................... 431

Sharpness Filters............................................................................. 432Edge Detect Filters .......................................................................... 432Other Filters ..................................................................................... 433

Clipping an Image................................................................................. 433Rotating an Image ................................................................................ 435Converting an Image to Another Format............................................... 435Modifying Image Transparency............................................................. 437

15 Working with Drillholes...................................................................... 439

Drillhole Data Workflow......................................................................... 440Data Formats ........................................................................................ 440

Drillhole Data Formats ..................................................................... 441Collar Table ................................................................................ 441Downhole Survey Table ............................................................. 442Downhole Data Tables ............................................................... 443Grid and Contour Surfaces......................................................... 444Surface Geology......................................................................... 444

Costean Data Formats..................................................................... 444Costean Collar Tables ................................................................ 444Costean Survey Tables .............................................................. 445Costean Downhole DataTables.................................................. 448Costean Grid and Contour Surfaces........................................... 449

Importing Drillhole Data from Other Drillhole Appliations...................... 450Creating and Managing Drillhole Projects............................................. 450

Creating a New Drillhole Project...................................................... 450Validating a Drillhole Database........................................................ 459

Modifying Invalid Data ................................................................ 461Modifying and Deleting Drillhole Projects ........................................ 464

Table of Contents xi

Assigning Costean/Trench Tables to the Project ............................. 465Opening Drillhole Projects................................................................ 469Saving and Restoring Drillhole Sessions ......................................... 470Creating a Subset of a Project ......................................................... 471Sharing and Packaging Drillhole Projects ........................................ 472

Creating Planar Sections and Plans...................................................... 473Vertical Section ................................................................................ 474

Previewing the Section Envelope................................................ 475Section Definition Parameters..................................................... 476

Horizontal Plan................................................................................. 477Plan Definition Parameters ......................................................... 478

Display Options ................................................................................ 478Downhole Data ........................................................................... 478Surfaces...................................................................................... 479Annotation................................................................................... 480Multiple Sections......................................................................... 481

Creating a Polyline Section ................................................................... 482Creating a Trench or Costean............................................................... 486

Create Trench Display ..................................................................... 487Create Trench Plans ................................................................... 487Create Trench Sections .............................................................. 488View Definition ............................................................................ 489

Apply Downhole Trench Data .......................................................... 491Combine Drillhole and Trench Section Views .................................. 492

Managing Sections and Plans............................................................... 493Display Section Parameters............................................................. 494Open Sections.................................................................................. 495Refresh Downhole Data ................................................................... 495Regenerate Sections........................................................................ 496Rename a Section............................................................................ 496Add a Section................................................................................... 497Close Sections ................................................................................. 497Delete Sections ................................................................................ 497

Displaying Downhole Data .................................................................... 498Missing Downhole Data Tables................................................... 503

Text Labels....................................................................................... 504Source Data ................................................................................ 505Style ............................................................................................ 505Position and Orientation.............................................................. 506Format......................................................................................... 506

Histogram/Linegraph........................................................................ 507Source Data ................................................................................ 508Scale ........................................................................................... 509Style ............................................................................................ 509Position ....................................................................................... 510

Trace Shade..................................................................................... 511Structure Ticks ................................................................................. 513

xii Encom Discover User Guide

Display........................................................................................ 514Output Legend and Reference Scales............................................. 514Using Setting Templates.................................................................. 515

Saving Setting Templates........................................................... 516Using Existing Setting Templates ............................................... 516Sharing Settings Templates Between Users .............................. 517Importing/Exporting Drillhole Projects and Their Setting Templates517

Displaying Downhole Logs.................................................................... 518Define Log Display........................................................................... 519Log Display Parameters .................................................................. 521Global Settings ................................................................................ 523

Legend Editor ....................................................................................... 524Create New Legend......................................................................... 526Modifying Legend Entries ................................................................ 527Additional Legend Modification Tools .............................................. 530Importing Legends ........................................................................... 531Export Legends................................................................................ 532Legend Configuration ...................................................................... 532

Adding Sections to a Layout ................................................................. 533Adding a Map Grid to Sections ............................................................. 537Creating a Section Collar Plan.............................................................. 538Interrogating Drillholes .......................................................................... 539Digitizing Boundaries ............................................................................ 539Calculating Sectional Resources .......................................................... 540

Setup Resource Parameters ........................................................... 542Downhole Compositing......................................................................... 545

Select Drillholes to Composite......................................................... 546General Settings .............................................................................. 547Composite Data Handling Options .................................................. 548Composite by Cut-off Grade ............................................................ 549Composite by RL or Downhole Depth ............................................. 552

Composite by Downhole Depth .................................................. 553Composite by RL ........................................................................ 554

Composite by Attribute .................................................................... 555Calculating 3D Coordinates .................................................................. 557

Calculating 3D Coordinates Midpoint .............................................. 558Calculating Maximum and EOH Values ............................................... 560

Analyse Maximum Downhole Grades.............................................. 560Analyse EOH Downhole Grades and Data Values.......................... 562

Saving Display Settings ........................................................................ 564

16 Working with Surfaces ....................................................................... 565

Introduction to Surface Gridding ........................................................... 567MapInfo Professional and Grid Files................................................ 569

Table of Contents xiii

Supported Grid Formats................................................................... 569About Grid Handlers......................................................................... 571

Creating Grids ....................................................................................... 571Interactive Gridding ............................................................................... 572

Using the Interactive Gridding Tool.................................................. 573Gridding Tool Preview Display ......................................................... 574Gridding Tool Input Tab ................................................................... 576

Statistics Explorer ....................................................................... 578Data Conditioning............................................................................. 578Field Data Conditioning.................................................................... 580

Invalid Data Values and Ranges................................................. 582Gridding Tool Method Tab ............................................................... 585

Minimum Curvature..................................................................... 586Kriging......................................................................................... 587Inverse Distance Weighting ........................................................ 591Search Tab ................................................................................. 594Spatial Neighbour ...................................................................... 597Triangulation ............................................................................... 598Density Grid ................................................................................ 598Distance Grid .............................................................................. 600

Gridding Tool Geometry Tab............................................................ 601Gridding Tool Output Tab................................................................. 603Statistics Explorer ............................................................................ 606

Spreadsheet................................................................................ 607Zoom, Selection and Display Controls ........................................ 609Display Modulation...................................................................... 610Subsetting ................................................................................... 610Univariate .................................................................................... 610Bivariate ...................................................................................... 615Spatial ......................................................................................... 617Variogram ................................................................................... 619Model Variograms....................................................................... 621

Large Multi-file Triangulation ................................................................. 624When to Use Large Multi-file Triangulation ...................................... 625Using the Large Multi-file Triangulation Tool.................................... 625

Running the Triangulation........................................................... 626The Triangulation Process .......................................................... 628Re-running the Triangulation....................................................... 629

Input Data Files ................................................................................ 629Interpolation Settings ....................................................................... 630

Data Conditioning ....................................................................... 631Gridding Properties ..................................................................... 631Options........................................................................................ 633Triangulation Parameters............................................................ 634Output Grid ................................................................................. 635

Converting Vector Surfaces to Grids..................................................... 637Interrogating a Grid ............................................................................... 639

xiv Encom Discover User Guide

Interactive Query ............................................................................. 639Summary Statistics .......................................................................... 640Statistics by Polygonal Region ........................................................ 641

Computing Grid Values by Expressions ............................................... 642Create Expression ........................................................................... 644

Grid Colour and Shading ...................................................................... 646Methods ........................................................................................... 647Transparency................................................................................... 648LUT Editor........................................................................................ 649Create Look-Up Table ..................................................................... 650Sun-Shading .................................................................................... 652

Sun Shade.................................................................................. 653Sun Highlight .............................................................................. 653Histogram ................................................................................... 653Percentile and Data Break Stretch Types................................... 655

Display a Colour Legend ................................................................. 657Filtering Grids ....................................................................................... 657

Preview Windows ............................................................................ 659Grid Filter Information ...................................................................... 660Applying Grid Filters ........................................................................ 661Filling Gaps...................................................................................... 661Saving the Filtered Grid ................................................................... 662Grid Filter Settings ........................................................................... 664

Contouring a Grid ................................................................................. 665Creating Contours............................................................................ 665Labelling Contours........................................................................... 667Positioning Contour Labels.............................................................. 669

Creating Polygonal Regions by Selection Criteria ................................ 671Select Cells by Value Range ........................................................... 672Select Cells by Multiple Value Ranges ............................................ 673Select Cells by Surface Property ..................................................... 675

Creating Grid Profiles............................................................................ 676Data Selection ................................................................................. 678Interrogating Profiles........................................................................ 680Navigating the Preview window ....................................................... 681Colouring and Controlling Profiles ................................................... 681Customizing the Preview Appearance............................................. 682Output .............................................................................................. 682

Creating Voronoi Polygons .................................................................. 683Calculating Surface Properties and Volumes ....................................... 685

Calculating the Volume Between Two Grids ................................... 685Calculating Volumes by Level.......................................................... 685Calculating Volumes Constrained by Polygons ............................... 686Calculating Slope and Aspect.......................................................... 686Calculating Curvature ...................................................................... 687Calculating Cut-and-Fill Volumes .................................................... 687Calculating Surface Areas ............................................................... 687

Table of Contents xv

Manipulating Grids ................................................................................ 688Using the Grid Utility Tool ................................................................ 690

Settings ....................................................................................... 693Save Output Grid ....................................................................... 694

Classify............................................................................................. 695Grid to Grid Clip ............................................................................... 697Clip ................................................................................................... 698Convert............................................................................................. 699Create RGB ..................................................................................... 700Curvature ......................................................................................... 701Cut/Fill .............................................................................................. 702Edit ................................................................................................... 703Fill Holes .......................................................................................... 705Flip ................................................................................................... 705Merge .............................................................................................. 705Outline.............................................................................................. 706Overlay............................................................................................. 707Replace ........................................................................................... 708Reproject.......................................................................................... 709Resample ......................................................................................... 712Rotate............................................................................................... 713Shift .................................................................................................. 715Slope ................................................................................................ 715Split .................................................................................................. 717Statistics........................................................................................... 717Surface Area .................................................................................... 720Vectorize .......................................................................................... 720Viewshed.......................................................................................... 721Volume ............................................................................................. 724

Dividing Grids into Tiles......................................................................... 726Tile Layout........................................................................................ 727Tile Naming ...................................................................................... 728

Assigning Values from a Grid to Map Objects....................................... 728Pre-computing Grid Statistics................................................................ 729Grid Handler Preferences...................................................................... 731

Initial Display .................................................................................... 731

17 Hydrological Surface Analysis........................................................... 735

Hydrology Workflow .............................................................................. 735Removing Unnatural Pits....................................................................... 738Extracting Drainage Features................................................................ 740

Flow Direction .................................................................................. 743Flow Accumulation ........................................................................... 744Define Stream Channels .................................................................. 745

Generating Catchment Areas................................................................ 747

xvi Encom Discover User Guide

18 Working with Structural Data............................................................. 749

About Structural Data ........................................................................... 749Displaying Structural Data as Orientated Symbols ............................... 750

Structural Data Options ................................................................... 752Digitizing Structural Data ...................................................................... 754Dip and Plunge Angles ......................................................................... 755Discover Structure Codes..................................................................... 756

19 Tenements........................................................................................... 759

Apply for an Australian Mineral Tenement............................................ 760Application Tables ........................................................................... 763Interactive Block Selection............................................................... 764Manual Block Selection ................................................................... 765

Displaying Graticular State Reference Grid .......................................... 766Searching Australian Tenements.......................................................... 768

Manage Tenement Tables and Holder Aliases................................ 769Downloading Tenement Data ............................................................... 771

Index .................................................................................................... 775

1 Managing the User Interface and Workspaces 1

1 Managing the User Interface and WorkspacesIn this section:

• Discover Menus

• Discover Toolbars

• Using the Discover Command Search Tool

• Organising Your MapBasic Tools

• Managing Your Workspaces

Discover Menus

When Discover starts, new menus and toolbars are added to the MapInfo interface. The Discover menu provides access to all Discover application menus, toolbars and tools.To open the menu, click Discover on the MapInfo menu bar.

As you move the cursor over each menu item, a message is displayed in the Status Bar at the bottom-left of the MapInfo window, which provides a short description of each item.

Some application menus are not displayed until selected from the Discover menu (such as Surfaces, Drillhole and Tenements) or from submenus (such as DigData on the Data Utilities menu).

To hide and show Discover application menus:

• To show a menu (and load the application module), on the Discover menu, click the menu name (i.e. Surfaces Menu, Images Menu, Drillhole Menu, GraphMap Menu, ColourMap Menu, or Discover 3D Menu).

2 Encom Discover User Guide

• To hide an application menu (and unload the application module), on the menu, click Exit (menu).

You can also automatically start selected application menus when Discover starts (see Getting Started: Auto-starting Discover).

See also...Reference Manual: Discover Menu...Getting Started: Understanding the User Interface...Getting Started: Configuring Encom Discover...Getting Started: Starting Discover

Discover Toolbars

When Discover starts, the Discover toolbar is added to the MapInfo interface. Other application toolbars are displayed depending on their auto-start settings (see Getting Started: Auto-starting Discover) or when the application menu is loaded.

Discover toolbar

As the cursor is moved over each toolbar button, a message is displayed in the Status Bar at the bottom-left of the MapInfo window, which provides a short description of each tool. The tools available from the Discover toolbar and Discover application toolbars are described in Reference Manual: Toolbars.

The Discover toolbars can be docked or floated, and hidden or displayed at any time.

To move a docked toolbar:

• Click the drag bar on the left of the toolbar and drag to another location.

To dock a floating toolbar:

• Click the title bar and drag to the docking areas at the top, bottom, left, and right perimeters of the MapInfo window.

To show and hide the Discover toolbars:

• On the MapInfo Options menu, click Toolbars, and then turn on and off the toolbars as required.


• You can also close a floating toolbar by clicking the window close button on the title bar.

• You can also hide and show some toolbars from the corresponding application menu; for example, click Show Map Window Buttons on the Discover Map Window menu to display the Map Window toolbar.

See also...Reference Manual: Toolbars...Getting Started: Understanding the User Interface

Using the Discover Command Search Tool

The Command Search tool lets you search for tools available from the Discover menus by name or keyword. The list of matching tools updates as you type. For example, you can type part of a tool name or the name of a module to obtain a list of all the matching and associated tools. Multiple keywords, separated by spaces, are treated with a logical AND. The search is not case sensitive.

To clear the search results and revert to the list of recently used tools, click the clear search button . The categories of search results can be collapsed and expanded by clicking the arrow symbol next to the category title.

To run a tool, click the tool name on the list.

To hide and show the Command Search tool when Discover starts:

1. On the Discover menu, point to Configuration, and then click Settings.

2. Under Automatic start, under Auto-start modules, select or clear the Command Search check box.


The categories of tools searched and other options can be customised.

To change the Command Search settings:

1. In the Command Search box, click the Options button .

The Command Search Options Dialog Box is displayed.

2. Under Categories to search over, use the controls to move categories of tools from Selected to Unselected and vice versa. Click and drag to select multiple categories, or hold the SHIFT or CTRL key while selecting from the list.

3. Under Other Options, choose the text size, “recently used” settings, and tool transparency.

See also...Getting Started: Configuring Encom Discover...Reference Manual: Discover Command Search Tool

Organising Your MapBasic Tools

A MapBasic tool is generally a custom or free-ware tool written in the MapInfo MapBasic programming language that provides additional functionality to MapInfo and Discover. MapBasic tools have an .MBX file extension.

Note Configuration files specifying the contents of each category and icon images are stored in the Discover Menu folder.

The Favourite MapBasics tool enables frequently used MapBasic tools to be added to a list where they can be quickly selected and run. Favourite MapBasic tools can also be assigned an “alias” name to make it easier to determine the contents of the MapBasic program in the list if desired.


Favourite MapBasics

To add a favourite MapBasic tool:

1. On the Discover menu, point to Table Utilities, and click Favourite MapBasics.

The Favourites dialog box is displayed.

4. In the Name box, type an alias for the MapBasic tool.

5. Click OK to add the MBX to the list of favourite MapBasic MBXs on the Favourites dialog box.

6. Repeat steps 2 through 5 to add another MapBasic tool to the list.

7. Click Close to finish.

2. On the MapBasic MBXs tab, click Add.

The Add Favourite dialog box is displayed.

3. Next to the File path box, click the Open button and browse to the location of the MapBasic tool.


To run favourite MapBasic tool:

To maintain your MBX favourites:

See also...Reference Manual: Discover>Table Utilities>Favourite MapBasics

Managing Your Workspaces

• Favourite Workspaces

• Checking and Modifying Table Locations in a Workspace

• Preparing a Workspace for Sharing and Archiving

• Fixing Problems in a Workspace



2. On the MapBasic MBXs tab, double-click the MapBasic tool or select the MBX and click Run MBX.



2. On the MapBasic MBXs tab:

• To remove a MapBasic tool, select and click Remove.

• To edit a MapBasic tool name or location, select and click Edit.

• To re-order MapBasic tools, select and click the Up and Down arrow buttons to move it up and down the list.


Favourite Workspaces

Favourite Workspaces

To add a favourite workspace:

1. On the Discover menu, point to Table Utilities, and click Favourite Workspaces.


4. In the Name box, type an alias for the workspace.

5. Click OK to add the workspace to the list of favourite workspaces on the Favourites dialog box.

6. Repeat steps 2 through 5 to add another workspace to the list.


The Favourite Workspaces tool enables frequently used workspaces to be added to a list where they can be quickly opened. Favourite workspaces can also be assigned an “alias” name to make it easier to determine the contents of the workspace in the list if desired. Workspaces have a .WOR file extension.

2. On the Workspaces tab, click Add.

The Add Favourite dialog box is displayed.

3. Next to the File path box, click the Open button and browse to the location of the workspace file (.WOR).


To open a favourite workspace:

To maintain your favourite workspaces:

See also...Reference Manual: Discover>Table Utilities>Favourite Workspaces

Checking and Modifying Table Locations in a Workspace

Use the Discover Workspace Editor to check and modify table references in workspaces. To open the editor, from the Disover menu, point to Table Utilities, and then click Workspace Editor.

Under Tables in workspace, the status of each table is listed as either OK, Unused or Missing:

• OK: the table is used in the workspace, i.e. displayed in a map window or browser and that the file path to that table is correct.

• Unused: the table is open but not displayed in a map window or browser in the workspace.



2. On the Workspaces tab, double-click the workspace or select the workspace and click Open Workspace.



2. On the Workspaces tab:

• To remove a workspace, select and click Remove.

• To edit a workspace name or location, select and click Edit.

• To re-order worksapces, select and click the Up and Down arrow buttons to move it up and down the list.


• Missing: the table is set to display in a map window or browser but the table cannot be found in the location specified by the file path.

It is recommended that you select the Save backup of workspace before changes check box before applying changes to any tables and path names.

To remove unused tables:

1. From the Workspace Editor click Open Workspace.

2. Close the unused tables.

3. Save the workspace.

To resolve missing tables:

• If the table no longer exists, use the MapInfo Workspace Resolver or Discover>Table Utilities>Open Workspace Advanced tool (see Fixing Problems in a Workspace) to remove the reference to the table.

• If the file path is incorrect, from the Workspace Editor, select the table, click Edit Selected Path, and then browse to the new table location.

To make table path names absolute or relative to the workspace folder:

From the Workspace Editor,

• Click Set All to Current to set the path names of all tables to the same folder as the workspace.

• Click Set All to Absolute to save the selected drive and directory path for all the tables in the workspace.

• Click Set All to Relative to make the path names of all tables located under the folder where the workspace is stored relative to the workspace folder. If the table folder is not located under the workspace folder, the full path is preserved.

Other functions available from the Workspace Editor include:

• Select the Turn off editable layers check box to turn off all the editable layers in all map windows. This is useful when a workspace is to be written to CD-ROM or to prevent other users from making modifications to tables.


• Select the Open all with interactive check box to open all tables in a workspace in interactive mode. In interactive mode the user is prompted to browse for a new table location if the workspace file path is incorrect. If the file path in a workspace is not interactive and a table is not present in the saved file location, the workspace will not open.

• Select the Remove printer settings check box to delete the printer setting information from a workspace.

See also... Fixing Problems in a Workspace...Reference Manual: Discover>Table Utilities>Workspace Editor...Reference Manual: Discover>Table Utilities>Open Workspace Advanced

Preparing a Workspace for Sharing and Archiving

Before writing a workspace and its tables to portable media, such as a CD-ROM, or archiving as a zip file, use the Workspace Editor and Save Tables and Workspaces tools to check and consolidate the tables referenced in the workspace to a single folder.

To prepare a workspace and tables for packaging:

1. Use Discover>Table Utilities>Workspace Editor to check for unused and missing tables and to turn off editable layers. You can also use the Workspace Editor to save tables to the workspace folder and make table names relative or absolute. For more information, see Checking and Modifying Table Locations in a Workspace.

2. Use Discover>Table Utilities>Save Tables and Workspace to save the workspace and all open tables in a workspace to a single folder.

See also... Fixing Problems in a Workspace...Checking and Modifying Table Locations in a Workspace...Reference Manual: Discover>Table Utilities>Save Tables and Workspaces

Note All tables saved to a new folder using Save Tables and Workspace will be saved as native MapInfo files regardless of their original format (Excel, Access etc) with the exception of raster images.


Fixing Problems in a Workspace

Use Discover>Table Utilities>Open Workspace Advanced to check workspaces with missing or corrupted tables and to fix links and commands. This allows workspaces with complex layouts and customized map views to be opened when some tables are missing or corrupted.

After selecting the workspace, the Workspace Loader dialog is displayed, from which you can:

• Load Hidden TablesHidden tables that were open when the workspace was created are loaded by default. Uncheck this box to not load hidden workspace tables

• Load Printer SettingsPrinter settings captured when the workspace was created are loaded by default. Uncheck this box to not load workspace printer settings.

• Pause on ErrorBy default the workspace loader utility will pause when an erroneous command line is encountered. It is recommended to always have this option enabled.

• Step Line-by-LineIf the Step Line-by-Line box is checked, each time the Run button is pressed the workspace loader utility will advance through the workspace one line at a time. This enables the user to edit and test the workspace command lines as the workspace is loading.

Click the Run button to automatically run through each command of the workspace file in the Current Statement Editor window at the top of the dialog. The status of each command is displayed in the bottom Status window with either an OK or ERROR message.


Workspace Loader showing erroneous command line encountered

When an erroneous command line is encountered, the utility will pause and display it in the Current Statement Editor. The ERROR message in the Status window will be accompanied by an error description. The errors are detailed in the table below along with recommendations as to whether the erroneous command needs to manually edited in the Current Statement Editor or skipped using the Skip Line button. The error message table can also be accessed via the Error Message Definitions button at the base of the dialog.

Error Message Solution

“Unable to open table XXXX” Table XXXX has been deleted or corrupted. Skip the command

“Table XXXX is not open” The Open Table command has been skipped for table XXXX. Delete the reference to table XXXX in the Current Statement Editor, then press Continue.

“ERROR” with no message Skip Line

“Invalid view layer” This command line references an unopened table. Skip Line


More advanced users can use this tool to run MapBasic scripts coded into a workspace.

See also...Checking and Modifying Table Locations in a Workspace...Reference Manual: Discover>Table Utilities>Open Workspace Advanced

2 Map Window Controls 15

2 Map Window ControlsIn this section:

• Map View Settings

• Map Projections

• Displaying Map Coordinates, Distances and Bearings

• Display a Dynamic Scale Bar Window

• Add a Dynamic Map Grid to a Map Window

• Window Size and Zoom Controls

• Linking Map Windows

Map View Settings

• Setting the Default Map View

• Saving and Restoring the Mapper State

• Saving and Applying View Settings

Setting the Default Map View

MapInfo stores a default view for each layer in a map window. When a new map window is opened for a table, the layer is displayed in this default view. Use the Discover Discover>Map Window>Set Default Table View tool to change the default view. This feature is not applicable for raster tables. Set the default table view to display an entire data layer or to only display a selected area for large data tables.

See also...Reference Manual: Discover>Map Window>Set Default Table View


Saving and Restoring the Mapper State

See also...Reference Manual: Discover>Map Window>Save/Restore Mapper State

Saving and Applying View Settings

Standard Views dialog

Use the Discover>Map Window>Save Mapper State tool to save the position, size, centre point and zoom width of the front map window. After saving the map window state you can then restore it with Restore Mapper State. The Restore Mapper State option is useful when you want to restore a map window that is used in a layout window after you have zoomed or panned across the map window.

Use the Discover>Map Window>Standard Views tool to store the current map window geographic extents and window dimensions. By storing the geographical extents over a project area or area of interest the current map window view can be quickly re-positioned over the location defined by the selected view. Standard Views can be used with any open datasets and are independent of the current map window projection.


To add a standard view:

1. Display the extents of the project area or area of interest in the current map window.

4. In the Description box, type the name for the view and click OK.

5. To add another view zoom and pan the current map window or set up a new view in another map window, and then repeat steps 3 and 4.


To apply a standard view:

1. Open the dataset or datasets in a new map window.

2. Select Discover>Map Window>Standard Views.


3. On the Standard Views dialog box, click Add.

The Add View dialog box is displayed, which shows the map window extents and size.

3. To apply the saved view geographical extents, double-click the view or select the view and click Restore View..

Alternatively, to apply the saved view geographical extents and window dimensions, select the view and click Restore View & Size.


To maintain standard views:


2. From Standard Views dialog box,

See also...Reference Manual: Discover>Map Window>Standard Views

Map Projections

• Saving and Applying Map Projections

• Displaying Mapper Projection Details

Saving and Applying Map Projections

• To delete a view, select the view in the list and click Delete.

• To re-order views, select the view and use the Up and Down arrow buttons to move the view up and down in the list.

Note The selected view is applied regardless of whether there is any data in that area.

Use the Favourite Projections tool to create a list of frequently used map projections. Favourite projections are used to change the current map window from one projection to another.


Favourite Projections dialog

Any projections added to this list are also displayed in the first window of the Choose Projection dialog whenever a Discover utility requires a projection to be assigned.

Choose Projection dialog showing Favorite Projections


To add a favourite projection:

1. Select Discover>Map Window>Favourite Projections.

4. Click OK.

5. Repeat steps 2 through 4 to add another projection to the list.


To apply a favourite projection:

1. Select the map window to which the new map projection will be applied.


3. From the Favourite Projections dialog box, double-click the projection in select the projection and click Apply.

To view details of the new map window projection, see Displaying Mapper Projection Details.

Maintaining favourite projections:


2. From Favourite Projections dialog box,

Favourite Projections are stored in the DISCOVER.PRJ file in the .\Discover\Config folder. This file uses a similar format to the MapInfo projection file and can be opened and edited manually using a text editor such as WordPad.

The Favourite Projections dialog box is displayed.

2. Click Add. The Choose Projection dialog box is displayed.

3. Select the projection from the Category box and Category Members box.

• To delete a projection, select the projection in the list and click Remove.

• To re-order projections, select the projection and use the Up and Down arrow buttons to move the projection up and down in the list.


See also...Displaying Mapper Projection Details...Reference Manual: Discover>Map Window>Favourite Projections...Coordinates and Projections

Displaying Mapper Projection Details

Use Discover>Map Window>Current Mapper Projection to display details of the coordinate system for the front map window (or right-click in the map window and select from the shortcut menu). You can use the information in this window, together with with the MapInfo Professional Help and User Guide documentation on Working with Coordinate systems to understand more about how MapInfo uses coordinate systems and to create your own custom coordinate systems.

A table can be stored in a projection that is not defined in the MapInfo projection file (MAPINFOW.PRJ). In this case, the coordinate system name is undefined and is referred to as a custom coordinate system. It is accompanied by a list of the projection parameters. Use these parameters to add the new coordinate system to the MapInfo projection file.

Custom coordinate systems can also be created so data collected in local coordinate systems such as a mine grid can be overlain with data collected in real world projections such as UTM or Lat/Long. See Coordinate Transformations for more information on creating a custom projection.

See also...Coordinates and Projections...Displaying Map Coordinates, Distances and Bearings...Saving and Applying Map Projections...Coordinate Transformations...Reference Manual: Discover>Map Window>Current Mapper Projection

Displaying Map Coordinates, Distances and Bearings

Use the Discover>Map Window>Distance and Bearing tool to:

• View the current cursor location in coordinates from one or more projections.

• Measure the distance and bearing between two map window locations.

• Display the browser entries for a selected table continuously as the cursor moves over map objects in the map window.


Cursor Coordinates

The cursor position coordinates in the current map window projection are displayed continuously in the Location Display dialog box as the cursor moves within the map window. Click Select alternate projection for position to display coordinates in an additional projection. For example, the cursor position can be viewed in UTM and Lat/Long coordinates or UTM and Local Grid coordinates at the same time.

The Location Display window can be moved by dragging the window title bar. To close the Location Display window click the button in the top-right corner.

Measuring Distance and Bearing

The Bearing and Distance measurements displayed are taken from the last selected cursor position. To start measuring, click at the desired location in the map window. The bearing and distance measurements from the selected location to the current cursor location are displayed in the Location Display window. The measurements are updated continuously as the cursor is moved within the map window. Click in the map window again to re-start the bearing and distance measurements.

Object Attributes

In addition to coordinate display and bearing/distance measurements the browser attribute entries for a selected table can be displayed as the cursor is moved over map objects within the map window. In the Details for pull-down list choose the table to display the browser information. Move the cursor over the map objects to view the browser entries from the selected table. To stop displaying browser entries select <None> from the Details for pull-down list.

Note The coordinates displayed in the Location Display window may appear different to those displayed by the MapInfo cursor position due to in-built rounding in the MapInfo coordinates. Discover reports and displays the coordinates as reported by MapInfo for the screen position. The precision of the coordinate locations is dependent on the map window zoom level, the higher the zoom the greater the coordinate precision.

Note When selecting map window locations to be used in Bearing and Distance measurements, map objects cannot be selected using the MapInfo Snap utility.


See also...Reference Manual: Discover>Map Window>Distance and Bearing tool...Coordinates and Projections...Coordinate Transformations...Map Projections

Display a Dynamic Scale Bar Window

A customizable scale bar, which dynamically scales with the current mapper window, can be displayed in a separate window. The scale bar dynamically updates the scale when the current map window is zoomed and resized, or when another mapper window is selected.

To display the dynamic scale bar:

• On the Discover menu, point to Map Window, and click Show Dynamic ScaleBar. The scale bar is displayed in a separate window.

To modify the appearance of the dynamic scale bar:

1. Right-click in the Scalebar window and select Options from the shortcut menu. The Scalebar Options dialog box is displayed.

Changes to the scale bar properties are displayed in the Preview box.

2. Under Type, select the scale bar style, number of segments, and units.

3. Under Display, select the scale bar colour and the placement, font size and font of the labels.

Note If the map window has scroll-bars enabled, the browser details may not be displayed when the cursor is placed over an object. Remove the scroll-bars using the Map>Options menu option.


To add the scale bar as a static object to the map window:

1. Right-click in the Scale Bar window and select Save to Map from the shortcut menu.

2. From the Save Scalebar dialog, either type the position of the top-left corner of the scalebar in the X and Y boxes, or click Select On Map to locate the scale bar interactively.

3. To change the location of the table the scalebar is saved to, under Output, click the Save button and navigate to the required folder.

4. Click OK to save the scale bar and display in the map window.

See also...Reference Manual: Discover>Map Window>Show Dynamic ScaleBar...Map Projections...Map View Settings...Coordinates and Projections...Creating Scaled Maps...Add a Map Grid

Add a Dynamic Map Grid to a Map Window

A dynamic Autogrid can be added to the front map window. The map window grid coordinates are updated automatically whenever the map window is zoomed or panned. The Autogrid re-displays the new map window coordinates on the fly when the window view dimensions are modified and can be turned on and off as required.

An Autogrid is ideal for interactive work, but when creating grids for presentation purposes in scaled maps, you should use a static map grid as described in Map Making.

To define and add an Autogrid to the front mapper window:

1. On the Discover menu, click Map Autogrid.

2. The Setup Map Autogrid dialog box is displayed. See Add a Map Grid for information on setting the grid display options.

After the grid is defined and displayed, the Autogrid menu and toolbar are displayed.


To hide and show the Autogrid:

See also...Reference Manual: Discover>Map Autogrid...Creating Scaled Maps...Add a Map Grid...Map Projections...Map View Settings...Coordinates and Projections

Window Size and Zoom Controls

The following tools allow you to use objects to reset the map window. The map window can either be fitted to the bounding rectangle of an object, or zoomed to the extents of the object (or objects) without changing the aspect ratio (height to width ratio) of the window:

• Fit the Map Window to the Selected Object

• Zoom to the Extents of the Selected Object

Fit the Map Window to the Selected Object

This is useful when adding a frame of specific size to a layout. Use the drawing tools or Discover>Object Editing>Key In Shapes tool to create a rectangle covering the area to print, and then use Fit Map Window to Selected Object to re-size the map window to the selected rectangle.

• Display of the Autogrid can be toggled from either the menu or by clicking the toolbar button.

Each time the grid is turned on the Setup Map Autogrid dialog is displayed. The last entered grid line styles and colours are retained between views but label positions need to be specified each time if they vary from the default. To close all currently open autogrids use the Autogrid>Exit Autogrid menu option.

Note Map Autogrids cannot be removed from a map window through the Layer Control or Enhanced Layer options.

Use Discover>Map Window>Fit Map Window to Selected Object to resize the map window to the aspect ratio of the selected object and to zoom and re-position the map window to display the minimum bounding rectangle of the selected object.


This tool can also be used to display an entire map object when a selected region or polyline object is much larger than the current map window zoom level. In this case, remember that the aspect ratio of the map window is fitted to the object’s bounding rectangle.

See also...Reference Manual: Discover>Map Window>Fit Map Window to Selected

Object... Zoom to the Extents of the Selected Object...Managing Maps and Layers...Matching the Sizes of Linked Windows

Zoom to the Extents of the Selected Object

See also...Reference Manual: Discover>Map Window>Zoom to Extents of Selected

Objects... Fit the Map Window to the Selected Object...Managing Maps and Layers

Linking Map Windows

Map Linking provides the ability to geographically link mapper windows so that any pan or zoom update applied to one mapper is automatically applied to all other map windows included in the linked group.

Access Map Linking by either:

• Select Discover>Map Window>Map Linking.

• Right-click in a map window and select Map Linking from the shortcut menu.

Note For objects that have an aspect ratio of less than 0.1 or greater than 10, the selected object does not completely fill the map window.

Select the object or objects, and then select Discover>Map Window>Zoom to Extents of Selected Objects (or right-click and select Zoom to Extents of Selected Objects from the shortcut menu) to zoom the map window to show the entire minimum bounding rectangle of the selected object(s).

Note The Enhanced Layer Control (ELC) of Discover provides for unlimited Previous Views of map windows.


Map Linking dialog to select and enable mapper windows

The Map Linking dialog lists all currently open mappers and the projection of each. Use the checkboxes next to Mapper names to select/unselect mappers. Select All and Unselect All buttons are also provided.

Two mapper Linking Methods are available:

• Fixed extents - The windows are synchronised so that the window centre point and the X axis extents are always visible in the map window regardless of either the map scale or the window dimensions.

• Fixed scale - Following a pan or zoom, the new map centre and scale are applied to the other linked mappers. Thus, each linked mapper window has the same centre coordinate and scale but the amount of data shown in each depends on the individual window size and dimensions.

Individual mappers can also be linked via the Link this map option on the pop-up menu from a right mouse click in a mapper. A tick next to this menu item indicates that the mapper is linked. Selecting the option toggles the linkage.

After selecting the map windows to be linked and method to use, click OK.


The Map Link option can be deselected from either the Map Linking dialog by clicking Unselect All or by the right-mouse click pop-up menu in any linked window and deselecting the Link this map option. When this option is disabled the menu item will not show a tick beside it (see above).

See also...Reference Manual: Discover>Map Window>Map Linking...Show Cursor Position in Linked Windows...Matching the Sizes of Linked Windows

Show Cursor Position in Linked Windows

Cursor Positioning dialog and window selection

Select the map windows to display the cursor locator symbol by placing a check next to each window box. Sometimes the cursor position selected in one mapper is not currently visible in another mapper because the data coverage does not include the selected position. Check the Pan mapper to show cursor position box to pan the map window view to show the cursor position.

The cursor symbol style button allows you to modify the Cursor position symbol to any of the standard MapInfo symbols. To adjust the symbol style, press the Symbol button or use the MapInfo menu item Options>Symbol Style.

Interactive Cursor Positioning displays the same geographic location in separate mapper windows by placing a symbol at the same position as selected in one linked window. If the cursor position is not visible in a linked map window the mapper can be panned to show the selected location.


Cursor positioning is a useful function in circumstances where you wish to use a mapper as a ‘locator’ and review data at a different scale in a second or third window. An example of two windows with the location symbol placed at the same geographic position but with different scales and information content is shown below:

Cursor Positioning showing a symbol placed at the same geographic location

The Cursor Position operation can be deselected at any time by clicking on the Cursor Position Off button on the Cursor Position toolbar.

See also...Reference Manual: Discover>Map Window>Cursor Position Menu...Linking Map Windows...Matching the Sizes of Linked Windows


Matching the Sizes of Linked Windows

The Map Window>Match Window Sizes option allows linked mapper windows to be displayed in the standard size map window. If tables are displayed in a number of different sized linked mapper windows the preferred map window size can be selected and all other map windows will be re-sized to these map window dimensions. This allows for easy comparison of the same area between the linked map windows.

See also...Reference Manual: Discover>Map Window>Match Window Sizes... Linking Map Windows

3 Importing and Exporting 31

3 Importing and ExportingIn this section:

• Importing Data with MapInfo and Discover

• Import Formats Supported by Discover

• Tabular and Vector Data

• Raster Imagery

• Surface Grids

• Drillholes

See also...Reference Manual: Supported Data File Formats...Registering and Rectifying Raster Images...Saving a Map Window as a Registered Raster Image...Making Movies and Animations from Map Windows

Importing Data with MapInfo and Discover

Your combined MapInfo Professional/Discover GIS platform can import in excess of 100 industry standard and third-party data formats. These include:

To import tabular and vector data, use:

(including databases, contour files, text files, etc.)

• MapInfo File>Open

• MapInfo File>Universal Translator

• MapInfo Table>Import

• Discover>Import and Export (see )

To import raster imagery, use:

(such as aerial photography, SPOT imagery, company logos, etc.)

• MapInfo File>Open Raster Image

• Discover Images>Rectify Image (see )


To import gridded surfaces, use:

(such as digital elevation models and geophysical grids)

• MapInfo File>Open Grid Image

• Discover Surfaces>Import Grid File (see )

To import drillhole data, use:

• Discover Drillholes>Import or Export (see )

Every file format that can be imported into MapInfo Professional and Discover is listed in Reference Manual: Supported Data File Formats, as well as the location of the corresponding import tools. File formats are listed by source (e.g. Landmark Grid files) and file name extension (e.g. GRD).

A range of additional formats can be imported using Safe Software’s Feature Manipulation Engine (FME).

Import Formats Supported by Discover

Tabular and Vector Data

• acQuire

• ASCII Data

• Datamine

• DataShed

• DataSight

• DXF

• Geosoft

• Gemcom

• ioGAS

• LIDAR LAS

• MicroMine


• MineSight

• Surpac

• Vulcan

• Import, Reproject and Convert Vector Files

Raster Imagery

• Rectifying Raster Images

• ECW/JPEG2000

• Importing an EGB Image

• Exporting as an EGB Image

• Saving a Map Window as a Registered Raster Image

Gridded Surfaces

• ASCII Grid

• BIL Grid

• ER Mapper Grid

• ESRI ASCII Grid

• Geosoft Grid

• HGT Grid

• Minex Grid

• Surfer Grid

• Vertical Mapper Grid

• USGS DEM Grid

Import tools

• Convert v2.1 Grids

• Toggle Support for Vertical Mapper Grid


Export

• Export Grid to ASCII File

• Export Grid

Drillholes

• Discover Drillhole Projects

• gINT

• WinLoG

Tabular and Vector Data

• acQuire

• ASCII Data

• Datamine

• DataShed

• DataSight

• DXF

• Gemcom

• Geosoft

• ioGAS

• LIDAR LAS

• MicroMine

• MineSight

• Surpac

• Vulcan

• Import, Reproject and Convert Vector Files


acQuire

Discover>Import and Export>acQuire Database Import

The acQuire Import utility enables you to import drillhole or geochemical data directly from an acQuire® database into MapInfo tables for use with the Discover drillhole display module. The import utility uses the acQuire direct API to provide direct access to the acQuire database.

Due to database size and performance considerations Discover imports the selected data from the acQuire database into MapInfo .TAB files rather than establish a live connection to the data. Therefore, if the data is modified or updated in the database you will need to import a new copy of the data into Discover to make sure you are using the latest information.

To import data from an acQuire database:

1. On the Discover menu, point to Import and Export, and then click acQuire Database Import.

The Import from acQuire Dialog Box is displayed.

2. Under Mode, select either Drillholes or Point samples.

3. Under Commands, click Select data from acQuire to connect to the acQuire database. Refer to the acQuire documentation for information about creating database connections and how to use the acQuire API interface to select the data you want.

4. Click Choose MapInfo projection and choose the projection that the collar coordinates were recorded in.

5. In the X field and Y field boxes, select the fields containing the X and Y coordinates.

6. Select Open database to display the table in a browser window. Select Create map to display the table in a map window.

7. Click Save acQuire Settings to retain these settings for future use. Next time the acQuire data is to be displayed use the Load acQuire Params button to re-load a saved acQuire database query.

8. Click Import.

Note The acQuire database import supports all acQuire data models up to 4.2.0


The Choose Output Files Dalog Box is displayed.

9. Next to the Collars file box, click the Open button to select the output folder and file name. When selected, the other output file locations are updated to match. Click in any box to edit the defaults or click Open.

10. To disable import of the survey, lithology or assay data table, clear the Import check box adjacent to each file name box.

11. Press the OK button to complete the import process.

See also...Reference Manual: acQuire Database Import Tool

ASCII Data

Discover>Import and Export>Advanced ASCII Import

The Discover Advanced ASCII Import utility is designed to import external multi-column ASCII data files into a MapInfo .TAB file.

Features of the Advanced ASCII Import include:

• Flexible import format that can accommodate any number of ASCII data columns.

• Can read ASCII files with either fixed width (defined by column size) or delimited by user defined characters.

• Easy interface for column naming can use a header line or interactive dialogs. Unwanted header records can be skipped during the import.

• Comment lines are accommodated as are various data formats such as real, and scientific notation.

• Data specification can include multi-channel and banded data (for example, EM data)


• Use or save templates to describe the data format for re-use. Comments, headers and nulls are all handled in the templates.

To view samples of ASCII files that you can import, see Supported ASCII File Formats.

After data is imported, it is saved to a .TAB file and automatically opened in a browser view. If X and Y columns are present in the file, points will automatically be created and displayed in a map window.

To import an ASCII file:

1. On the Discover menu, point to Import and Export, and click Advanced ASCII Import.

The ASCII Data Import Dialog Box is displayed.

2. Under Input file, click the Open button and select the ASCII file to be imported.

The first 100 data records of the file are displayed in the Data preview box. If the format is not supported (e.g. binary file or inappropriate text file), a warning message is displayed.

To examine the input file in an external text editor, click the Preview button. To change the default editor, click Options (see ASCII Import Options).

3. The file is scanned to determine whether if it is a fixed width or delimited format. View the sample records in the Data preview box.

To change the format, under Column Format, click a different format . A Fixed width file is one where each column is confined to fixed character positions on each line of the file. A Delimited data file is one where each column is separated from the others by single or multiple delimiter characters. Some common delimiters include spaces, tabs and commas. Additional delimiters can be typed in the Other box. A Comma delimited (CSV) file is a delimited format with a comma delimiter.


4. The column widths are indicated by vertical lines in the Data preview box. With fixed-width data, if fields that are not properly identified, you can add and move separators.

• To add a separator, click the new position in the Data preview box.

• To delete a separator, double-click the separator.

• To move a separator, click and drag it to a new position. Holding the CTRL key while you move a separator will also shift all columns to the right of the current column.

5. If the file contains header lines, under Header, select the Number of lines in header. The header lines are displayed in the Data preview box.

6. Column names can be assigned to each column either automatically from a header record or by selecting the name for each column.

• If column names are provided in the header:Under Header, select the Field names are in header on line check box and select which line of the header contains the field names. Click Get Field Names to update the preview. Only field names starting with alphabetic characters or underscores are accepted. To ignore an invalid leading character, using the Starting at char option.

• To manually assign column names:In the Data preview box, right-click the column label and select a standard field from the Fields Shortcut Menu or click Properties to create a new field name and type. Fields named Skip are not imported.

Click Field Summary to display a list of all the assigned column names and field data types. To change the field assignment and filed type, right-click the column label and click Properties.

7. Input data fields containing an asterisk (*), a solitary minus sign (-) or a space ( ) are automatically treated as null values. When imported, nulls are written out to the .TAB file as blanks in character fields and zeroes in numerical fields. To define a different null specifier string, (e.g. –999.99), right-click the column label and select a standard field from the Fields Shortcut Menu and click Properties. From the Properties Dialog Box, under Nulls, in the String interpreted as null input value box, type the null string. To apply the same null string to all input fields, select Apply to all fields.


The steps above describe the common tasks when importing ASCII files. For information about advanced ASCII import features, see:

• ASCII Import Options

• Line Number Record

• Ignored Records

• Ignored Characters

• Save and Reload ASCII Template

Supported ASCII File Formats

The Discover Advanced ASCII Import utility can load a wide range of ASCII multi-column formats. Typically the formats fall into the following classes:

No header or comments, multi-columns of constant width

1600 300200.0 6253800.000 56481.027 -0.010 1600 300220.0 6253810.000 56479.535 -999999 1600 300240.0 6253820.000 56478.371 -0.003 1600 300260.0 6253830.000 56477.547 -0.001 1600 300280.0 6253840.000 56477.035 -0.000 1600 300300.0 6253850.000 56476.781 -0.000 1600 300320.0 6253860.000 56476.707 -0.001 1600 300340.0 6253870.000 56476.723 -0.003 1600 300360.0 6253880.000 56476.734 -0.005 1600 300380.0 6253890.000 56476.660 -0.008

8. When you have completed defining the structure of the input file, click Import to create the .TAB file.


Header lines and comments with multi-columns of constant width

LINE EAST NORTH MAG GRAV \ This is a comment line used for information 1600 300200.0 6253800.000 56481.027 -0.010 1600 300220.0 6253810.000 56479.535 -999999 1600 300240.0 6253820.000 56478.371 -0.003 1600 300260.0 6253830.000 56477.547 -0.001 1600 300280.0 6253840.000 56477.035 -0.000 1600 300300.0 6253850.000 56476.781 -0.000 1600 300320.0 6253860.000 56476.707 -0.001 1600 300340.0 6253870.000 56476.723 -0.003 1600 300360.0 6253880.000 56476.734 -0.005 1600 300380.0 6253890.000 56476.660 -0.008

Geosoft-style data files having line numbers embedded as standard XYZ file

Line 1600 300200.0 6253800.000 56481.027 -0.010 300220.0 6253810.000 56479.535 * 300240.0 6253820.000 56478.371 -0.003 300260.0 6253830.000 56477.547 -0.001 300280.0 6253840.000 56477.035 -0.000 300300.0 6253850.000 56476.781 -0.000 300320.0 6253860.000 56476.707 -0.001 300340.0 6253870.000 56476.723 -0.003 Line 1700 300660.0 6243880.000 56476.734 -0.005 300680.0 6243890.000 56476.660 -0.008

Delimited data with inconsistent column widths with or without headers

1600,300200,6253800,56481,-0.01 1600,300220,6253810,56479.5,-1.00E+30 1600,300240,6253820,56478.4,-0.003 1600,300260,6253830,56477.5,-0.001 1600,300280,6253840,56477,0 1600,300300,6253850,56476.8,0 1600,300320,6253860,56476.7,-0.001 1600,300340,6253870,56476.7,-0.003 1600,300360,6253880,56476.7,-0.005 1600,300380,6253890,56476.7,-0.008


ASCII Import Options

The Options Dialog Box contains defaults for importing an ASCII file.

• If the Use last format file (*.i3) by default is checked, next time a saved format file (*.i3) is loaded by pressing the Load format button, the directory path of the previously loaded or saved format file directory will be used. If this option is left unchecked, the default path when browsing for a format file will be the same as the path of the ASCII file currently being imported (but with an .i3 extension).

• If the Rename selected easting field to X and selected northing to Y is checked the field names for the respective easting and northing columns will be changed to X and Y.

• Two options are available for the Auto-classify behaviour: Hide header when classified and Show dialog compacted. These options are toggles for the initial display of the Advanced ASCII import dialog. Auto-classification occurs when the Advanced ASCII importer can detect the ASCII structure upon loading a file without any prompts from the user.

• Null value inputs can be specified under the Properties dialog when right clicking on a particular field. To specify the output value of a defined null value, type in for example -9999 into the Output null value dialog box. Subsequent to importing the ASCII file, the defined null values will populate the MapInfo Browser.

• The input file can be previewed with an external editor of the user’s choice as set under the Editor option. By default this is set to WordPad.exe.

Line Number Record

Check the Import the Line Field box if there is a column containing a line identifier in your data. In some cases, there is not a line field in your survey data. Instead, the file contains a separate data line that specifies the start of each new survey line. The data following the line identifier are all the measurements relating to that survey line. The simplest example of this is for the line simply to contain the string Line x, where x is a survey line name e.g. 1020.

To import data from files with interspersed line numbers check the box Has interspersed line numbers and select an appropriate line number prefix from the pull-down list. If the line prefix that is not in this drop-down list, it can be typed in manually. The line prefix may be included in the output or can be left out altogether (e.g. Line 1020 or just 1020). When the Has interspersed line numbers option is enabled there is no need to select a field to be the Line field.


Ignored Records

Sometimes a file may contain additional data lines that are not needed in the data import. To enable Discover to ignore particular lines of data in an ASCII file, enter the symbol or text used at the start of the unwanted lines (e.g. “#”,”//”, etc) in the Comment Lines control. Make sure each entry is contained within quotation marks and multiple entries are separated by a comma.

To import the ASCII file select the Import button in the top-right corner of the dialog. You are then prompted to select the name of the TAB file that is created to contain the imported data.

Ignored Characters

To pre-process or filter out unwanted characters from the ASCII dataset, type the characters to ignore (such as *, %, $, #, @ or ?) into the Ignore characters text box (top left of the dialog). Once these characters have been defined, the Data preview will interactively change displaying the dataset without the specified characters. Upon import these characters will not be displayed.

Save and Reload ASCII Template

If you need to import a number of files with the same data layout it may be useful to save the ASCII import Template for later use. To do this, simply press the Save Format button and enter a name for the template. Make sure to save the import template before you start importing the data the format information is lost.

When you want to import another data file with an identical format, reload the saved template using the Load Format button. Discover will automatically configure the new data file with the appropriate field names, field properties, delimiters, column widths, etc.

Datamine

Discover can automatically import point or polyline files exported from Datamine® in ASCII format. Datamine ASCII files consist of header rows defining the field names followed by the rows of data.

MapInfo files can also be exported in Datamine ASCII format so they can be read directly into Datamine.

• Importing Datamine Points

• Importing Datamine Perimeters and Strings


• Exporting to Datamine

Importing Datamine Points

Discover>Import and Export>Datamine ASCII Import as Points

To import a Datamine ASCII point file:

1. On the Discover menu, point to Import and Export, and then click Datamine ASCII Import as Points.

The Advanced ASCII Import tool automatically recognises the standard Datamine ASCII point file structure and makes the relevant selections. To modify the automatic assignments, see ASCII Data.

2. Click Import.

3. You are then asked to select the output table and location, and select a projection.

Example Datamine ASCII point file:

IN FILE CREATED BY SYSTEM USING DATAMINE ON 03/05/28 8 8COLOUR N 1 1 -0.100000E+31XP N 1 2 0.000000E+00YP N 1 3 0.000000E+00ZP N 1 4 0.000000E+00PTN N 1 5 0.000000E+00PVALUE N 1 6 0.000000E+00SYMBOL N 1 7 -0.100000E+31LSTYLE N 1 8 -0.100000E+31 1.0 5669.462 3481.314 10148.0 1.0 182.0 201.0 1001.0 1.0 5670.037 3478.527 10148.0 2.0 182.0 201.0 1001.0 1.0 5668.771 3478.072 10148.0 3.0 182.0


201.0 1001.0 1.0 5668.072 3481.049 10148.0 4.0 182.0 201.0 1001.0 1.0 5669.462 3481.314 10148.0 5.0 182.0 201.0 1001.0 1.0 5666.332 3442.354 10148.0 1.0 183.0 201.0 1001.0 1.0 5665.804 3441.783 10148.0 2.0 183.0 201.0 1001.0

Importing Datamine Perimeters and Strings

Discover>Import and Export>Datamine ASCII Import as Polylines

To import a Datamine ASCII string file:

1. On the Discover menu, point to Import and Export, and then click Datamine ASCII Import as Polylines.

The Advanced ASCII Import tool automatically recognises the standard Datamine ASCII string (polyline) file structure and makes the relevant selections. To modify the automatic assignments, see ASCII Data.

2. Click Import.


Example Datamine ASCII perimeter or string file:

IN FILE CREATED BY SYSTEM USING DATAMINE ON 03/05/28 9 9String_N N 1 1 -0.100000E+31COLOUR N 1 2 -0.100000E+31XP N 1 3 0.000000E+00YP N 1 4 0.000000E+00ZP N 1 5 0.000000E+00PTN N 1 6 0.000000E+00PVALUE N 1 7 0.000000E+00SYMBOL N 1 8 -0.100000E+31LSTYLE N 1 9 -0.100000E+31 10.0 1.0 6034.375 4083.493 9045.26 1.0 176.0 201.0 1001.0 10.0 1.0 6031.418 4082.272 9045.213 2.0 176.0 201.0 1001.0


10.0 1.0 6028.923 4080.577 9045.14 3.0 176.0 201.0 1001.0 10.0 1.0 6027.251 4078.672 9045.131 4.0 176.0 201.0 1001.0 10.0 1.0 6025.765 4076.356 9045.239 5.0 176.0 201.0 1001.0 10.0 1.0 6025.11 4075.285 9045.262 6.0 176.0 201.0 1001.0 10.0 1.0 6024.77 4073.3 9045.316 7.0 176.0 201.0 1001.0

Exporting to Datamine

Discover>Import and Export>Datamine ASCII Export

To export a MapInfo table as a Datamine ASCII file:

1. On the Discover menu, point to Import and Export, and then click Datamine ASCII Export.

The Datamine Export Dialog Box is displayed.

2. Under File details, click the Input table box and select the table to be exported.

3. In the Output Datamine box, type or edit the output file name, or click the browse button to navigate to the output folder and file.

4. Under Elevation, click the Z value from column box and select the field that defines the elevation, or type a default elevation in the Default Z value box.

5. Under Attributes, select additional data fields (other than the X, Y, Z coordinates) to be exported into the output file. To select multiple columns, click and drag, or hold the SHIFT or CTRL key while you select columns.

6. If required, create a coordinate transform using the boxes under Coordinate Transform.

7. Click OK to start the export.

For more details, see Reference Manual: Datamine Export Dialog Box.


DataShed

Discover>Import and Export>DataShed Database Import

The DataShed Database Import utility is an installation option for users working with DataShed® databases. When the DataShed Database Import menu option is selected the DataShed menu is added to the MapInfo menu bar.

The link between MapInfo and the DataShed database is provided by the DataShed Geocomm utility. For information on how to run the Geocomm utility, refer to the DataShed documentation. All help enquiries should be directed to Maxwell Geoservices at [email protected].

See also...Reference Manual: DataShed Database Import Tool

DataSight

Discover>Import and Export>DataSight Import

DataSight is a platform for the management, communication and reporting of any natural resource data. DataSight handles information relating to any part of the sector—surface and groundwater, atmosphere, soil and others. DataSight stores data on the MS SQL Server platform and the DataSight Import Tool is designed to provide Discover users with a simple interface for connecting to, and importing data from SQL Server tables and views created by DataSight. This allows information stored in DataSight to be quickly visualised and analysed in its spatial and 3D context.

For more information, see:

• Server Authentication

• Access Methods

• Prerequisites for Using the DataSight Import Tool

• Using the DataSight Import Tool

mailto:[email protected]


Server Authentication

The DataSight Import Tool supports both Windows Authentication and SQL Server Authentication for connecting to MS SQL Server. Windows Authentication uses your Windows ID and password to access the database. If you select this option, you will be able to open the resulting .tab file or .wor files that contain this table without entering a user name or password. You do not have to enter a user name or password in the fields provided.

SQL Server Authentication requires that you enter a unique ID and password to access this database. If you select this option, you will be prompted for this ID and password each time you open this .tab file or access it in a workspace. Please see your database administrator to determine which authentication methods are enabled on your server.

Access Methods

The DataSight Import Tool supports two methods for connecting MapInfo to the server. A linked table is a MapInfo Professional table that is downloaded from a remote database and retains links to its remote database table. The remote database table is known as a DBMS table. When MapInfo Professional downloads a table, it copies the entire contents of the table to the local machine. Any changes you make to the copy can be committed to the server table at any time. We often recommend that you use linked tables rather than live tables to improve performance.

You can access remote data as a live access table using MapInfo Professional. It is called a live access because there is no local copy of the data, that is, all operations against the data go directly to the server. This differs from linked tables, which download a snapshot from the remote database into a native MapInfo Professional table.

You can perform most operations on a live access table that you do for a regular MapInfo Professional table. For example, you can view, edit, copy, and save a live access layer just as you can a regular MapInfo Professional table. However, you cannot pack or modify a live access table's structure.

You can create live access tables with or without a cache. The cache is a memory cache, which contains only the rows that are in the map display for that window. This optimizes certain operations such as ToolTips, labeling, etc. on the map. The cache is automatically updated when the view of the map changes, (for example, zooming or panning).


Prerequisites for Using the DataSight Import Tool

Before using the DataSight import tool, ensure that the following prerequisites have been established:

• An instance of SQL Server, containing at least one DataSight database.

• The user has a valid login for SQL Server and permission to read the DataSight database.

• The DataSight database has been configured to include GIS co-ordinates for stations, and that these co-ordinates have been populated.

• The user understands the map projection in which the GIS co-ordinates in DataSight have been created.

Using the DataSight Import Tool

Importing tables or queries from DataSight is a three-step process.

1. Load the DataSight menu.

2. Setup a database connection.

3. Create an SQL query and import data into a MapInfo table.

From the DataSight menu, you can also:

• Reopen a table using a previous SQL query.

• Delete a linked database table.

• Refresh a linked database table.

Load the DataSight import menu

• On the Discover menu, point to Import and Export, and click DataSight Connector.

The DataSight Menu is added to the menu bar.

Set up a database connection

1. On the DataSight menu, click Setup Database Connection.

The Setup Database Connection Dialog Box is displayed.


2. In the SQL Server box, type the name of a SQL Server instance that contains a DataSight database, or click Browse to select from the list of available SQL servers.

3. In the Authentication box, choose either <Windows Authentication> or <SQL Server Authentication>.

4. If SQL Server Authentication is selected box, in the User Name and Password boxes, type a user name and password

5. In the Select Database box, type the name of a DataSight database, or click Browse to select from the list of databases available on the selected SQL server.

6. To verify the connection, click Test Connection.

Create a new SQL query and import data into a MapInfo table

1. On the DataSight menu, click Import from DataSight.

2. In the Database box, select from the list of available database connections.

3. In the Available tables box, select a table or view to import. Click Advanced Table Filter to filter this list.

4. Under Select fields and criteria, move fields into the Selected box to include them in the imported table.

5. Select the Refine selection criteria check box if additional criteria are required to filter the rows imported into MapInfo.

On the Simple tab, use the expression builder to define selection criteria. To create a multi-line expression, in the Join column, select AND or OR, and then define the following criteria.

6. Click Next.

7. Under MapInfo Table Options, select either linked tables (recommended) or Live Access.

8. Under MapInfo Output Table, type a file name for the MapInfo table or press the disc button to open a save file dialog.

9. Select Table is Mappable to create points in the MapInfo table and click the symbol button to apply a point symbol style.


10. Press Projection to choose the appropriate projection to create the points (must match the projection used to create the Latitude / Longitude fields in DataSight).

Open data with an previous SQL query

1. On the DataSight menu, click Open Data from Template.

2. In the Table box, select a previous query.

3. Click Open.

Delete linked MapInfo tables

1. On the DataSight menu, click Delete linked MapInfo tables.

2. In the list box select a table to delete, the click Delete.

Refresh open tables

1. On the DataSight menu, click Refresh tables.

2. In the list box select a table to refresh, the click Refresh

DXF

The Discover DXF Import function has a major advantage over the MapInfo DXF Import utility and the Universal Translator (UT). The Universal Translator is available in MapInfo Professional v4.5 or later.

The major differences between using MapInfo, the Universal Translator and Discover are:

• Discover assigns layer names as attributes to each object. With MapInfo or UT, you cannot retain layering information unless you write each layer out to a separate file.

• MapInfo is much quicker than Discover for DXF importing.

• MapInfo allows you to transform the coordinates from CAD to World coordinates if necessary.

• MapInfo can store DXF object attributes in the MapInfo table.

• Discover stores the elevation of all objects into a column. MapInfo stores elevations only for lines or points, not polylines (such as contours).


All three import functions have merit. Use the one that is most appropriate for your situation.

DXF import and export tools available from Discover:

• DXF Import

• Export Contours to 3D DXF

• Export Digitized Boundaries to 3D DXF

DXF Import

Discover>Import and Export>DXF Import

Import layered CAD data into one MapInfo table, writing the CAD layer name as an attribute for each object. Optionally store a Z-value (for example, elevation) as an attribute for a map object.

To import a DXF file:

1. On the Discover menu, point to Import and Export, and click DXF Import.

2. Select the Input file by clicking on the Browse button

3. Select the output .TAB file name by clicking on the Browse button and selecting an appropriate location. By default Discover will save the Output file with the same name and in the same location as the source file.

4. Select the required object import method from the Create Object type pull down list. Two options are available:

• Points Only - create points for each vertex in the string file. Use this option to import the string vertices only and preserve the original string file X, Y, Z coordinate information.

• Auto Select - create either point or polyline objects depending on whether there are single or multiple line entries per block of data.

Note The X, Y coordinate values will not be imported into the browser for each vertex and the Z value will be an average of the vertex Z values for each string in the original file, as MapInfo does not support multiple vertex records per object in a browser.


6. Set the Coordinate Transform options to apply a transform to the data during import if required. The transform options allow you to Add/Subtract or Multiply the X, Y coordinates in the DXF file by constant values during import. This is especially useful if you need to convert the data from local mine grid coordinates to world coordinates.

7. Choose an Aspect from which to view the DXF file when it is displayed in MapInfo. View from Top, South or East.

8. If the DXF file is multi-layered select the Output each layer to a separate file option. This will create a separate MapInfo Table for each layer present in a DXF. Otherwise, a single MapInfo Table will be created containing all layers.

9. Press OK to commence the import process.

DXF Attribute Data

In your CAD drawing, you should digitize each rock type (or other data type) into an appropriately named layer. For example, digitize all basalt polygons to a layer called "Basalt", all tenement boundaries to a layer called “Tenement” and all stream polylines to a layer called “Streams”.

When Discover reads a DXF file created in your CAD package, all objects are inserted into the one table, but the DXF layer name is written as an attribute for each object. The end result is one table containing all DXF layers, each of which has an appropriate name as an attribute. You can then easily split out all objects of one type (such as basalts or tenements) and save them to a different table or join them to related attribute tables.

DXF Elevation Values

Elevation values are automatically stored from the DXF file and an extra Z is added to the new table. Note that for points, the elevation is unambiguous, but for multi-node objects such as polylines and polygons only one elevation is stored for an entire object. This elevation is the Z-value of the first node in the object. If a polyline defines a watershed or fence line for example, the first elevation is likely to be unrepresentative of the average elevation of the object.

5. Select an appropriate MapInfo projection for the data.

Note The MapInfo DXF import function allows you to store elevations of DXF lines, but not polylines. To store elevations of DXF polylines, you need to use Discover.


Export Contours to 3D DXF

Surfaces>Export Grid File or Contours>Export Contours to 3D DXF

Discover can export contour lines with attributes to 3D DXF files. Whilst MapInfo exports any map objects to a DXF file, it does not use an attribute (such as height) for the elevation field in a DXF file.

Use Discover to create 3D DXF files containing the Z value attribute from the contour line that can then be imported into AutoCAD, MicroStation or other 3D visualisation software.

Export Digitized Boundaries to 3D DXF

Drillholes>Boundary Digitizing>Export Boundaries

Objects digitized into a section boundary table can be exported to 3D DXF files for visualisation in 3D software systems including the Discover 3D add-on module. The 3D DXF format is compatible with AutoCAD® 2005.

Any type of map object (polylines, regions, points etc) may be digitized into the boundary table. When these objects are exported to 3D DXF, any attributes that have been added to the boundary objects are also exported.

Export boundary layers.

Choose the boundary to export from the Available Section Feature Layers list. Enter a Layer Name for the boundary or check the Use section name as layer name option. Discover can export section boundaries as a single 3D DXF file with all boundaries in one layer. In addition, a single 3D DXF file with separate layers for each boundary may be exported.


3D DXF files may also be created using unique attributes from a column in the section boundary table. For example, if one or more section boundary tables contain lithological boundaries for shale, sandstone, basalt, etc select the column that stores this attribute from the Multiple Files pull-down list. A series of 3D DXF files are created with each file containing all the lithology polygons for one unique attribute, e.g. Shale.DXF

Gemcom

Discover>Import and Export>Gemcom BT2 Import

Import Gemcom® binary triangulation files (.bt2) directly into MapInfo. A binary triangulation file is comprised of triangles representing a 3D solid or surface.

To import a Gemcom BT2 triangulation file:

1. On the Discover menu, point to Import and Export, and then click Gemcom BT2 Import.

The Gemcom BT2 Import Dialog Box is displayed.


2. Next to the Input file box, click the browse button and select the input file.

3. In the Output file box, type or edit the output table name, or click the browse button to navigate to the output folder and file.

4. In the Create Object type box, choose the object type. The surface can be imported as either points or 3D face objects.

5. Click Set Projection and choose the projection that the data coordinates were recorded in.


7. Under Aspect choose how it will be viewed in the map window: from the top, south or east.

8. Click OK to start the import.

See also...Reference Manual: Gemcom BT2 Import Tool

Geosoft

Discover>Import and Export>Geosoft Database Import

The Geosoft Import utility enables you to import data from a Geosoft® Oasis Montaj™ database into a MapInfo table. The imported data is stored in native MapInfo .TAB file format. When importing databases which contain multi-channel array data (such as Geotem or EM data) data into Discover each array channel will be imported as a single column. Because MapInfo Professional has a limit of 255 columns in a table any Geosoft databases which contain more than 255 channels will be truncated during import. In this situation you will be warned that some data loss will occur.

To import data from a Geosoft database:

1. On the Discover menu, point to Import and Export, and then click Geosoft Database Import.

The Import Geosoft Database Dialog Box is displayed.

Note The X, Y coordinate values will not be imported into the browser and the Z value will be an average of the vertex Z values for each string in the original file as MapInfo does not support multiple vertex records per object in a browser.


2. Next to the Input file box, click the browse button and select the .GDB input file.

3. If the data file contains spatial data, select the Has X and Y fields check box.

4. In the X field and Y field boxes, select the fields containing the X and Y coordinates.

5. To import a subset of records from the input file, click Select subset of lines, and then choose the lines to be included or excluded.

Select lines from Geosoft Database to import

6. Click Choose Projection and choose the projection that the data coordinates were recorded in.

7. Select Open in map to display the table in a map window. Clear the check box to display the data into a browser only.


For more details, see Reference Manual: Import Geosoft Database Dialog Box.

See also...Reference Manual: Geosoft Database Import Tool


ioGAS

Discover>Import and Export>ioGAS Menu

The ioGAS Import Tool is developed by Encom Technology in consultation with ioGlobal. This tool enables users to import ioGAS files and attributes directly into Mapinfo Professional® and save as a series of *.TAB files. The main data table contains the sample locations plotted in geographical space and displayed using the saved attribute symbology. Each attribute style also has an associated legend table.

To load the ioGAS menu:

• On the Discover menu, point to Import and Export, and then click ioGAS Import.

You can also use the MapInfo Tool Manager to autoload ioGASImport.MBX , which is located in the Discover folder.

To import an ioGAS file:

1. On the ioGAS menu, click ioGAS.

The ioGAS Importer Dialog Box is displayed.

2. Under Input file, browse to the .GAS file to be imported.

3. Under Field assignments, review and select the input field assignments.

4. In the Null Value box, type the value that will be substituted into any blank field records in the .GAS file. Otherwise, Mapinfo sets blanks to zero.

5. Under Field selection, use the controls to select additional fields to be imported.

6. Under Display options, choose if you want to import all data records, or only data that is visible in ioGAS.

7. Under Output options, select the output table name and location.

8. Click Projection and choose the projection that the coordinates (see Field assignments above) were recorded in.



When the data is imported a map window is displayed which contains the attributed data. Three legend windows are also opened which correspond to each of the colour, shape and size attributes used in the map window.

Imported MapInfo table and attribute legends

To refresh an imported table and thematic map from ioGAS:

• On the ioGAS menu, click Refresh Table.

This will overwrite the existing Mapinfo table. Use File>Save Copy As to preserve the original table.

See also...Reference Manual: ioGAS Menu

LIDAR LAS

Discover>Import and Export>LIDAR LAS (ASPRS) Import

The LIDAR Importer allows a quick and efficient way of importing ASPRS standard LAS files into MapInfo TAB files, creating the associated attributed points.

Note To avoid truncation of table names, keep ioGAS file names under 31 characters.


LAS is a binary format defined by ASPRS (www.asprs.org).

Importing LAS files into Discover

1. On the Discover menu, point to Import and Export, and then click LIDAR LAS (ASPRS) Import.

The LAS Import Dialog Box is displayed.

2. Next to the Input file box, click the browse button and select the LAS input file.

3. In the Output file box, type or edit the output table name, or click the browse button to navigate to the output folder and table.


5. Click Choose optional fields and choose additional data fields (other than the X, Y, Z coordinates) to be imported into the output table.


7. Click Import.

For more details, see Reference Manual: LAS Import Dialog Box.

MicroMine

Discover>Import and Export>MicroMine Import

Import MicroMine® data and string files into MapInfo tables. Discover reads the MicroMine file, creates an appropriately structured table and inserts the data.

To import a MicroMine file:

1. On the Discover menu, point to Import and Export, and then click Micromine Import.

2. You are asked to select the input file and output table, and then the MicroMine Import Dialog Box is displayed.

Note LIDAR LAS datasets can also be directly interpolated to create a gridded surface using the Large Multi-file Triangulation tool in the Discover Surfaces module

http://www.asprs.org


3. Select the input file data type:

• Data file: Select if the file contains sample and drillhole information, including survey and downhole data files. The Micromine Data Import Dialog Box is displayed.

• String file: Select if the file contains string (polyline) data. The Micromine String Import Dialog Box is displayed.

4. Select the import options:

• For string files, select the fields in the input file that define the X and Y coordinates, and the string ID. Options are also provided for creating closed polygons and defining the line style.


MineSight

The MineSight Import utility enables you to import MineSight® SRG string files into MapInfo tables. The data can either be imported as points representing each vertex in the string file or as strings (polylines).

MapInfo files can be exported in MineSight SRG format so they can be read straight into MineSight.

• Importing MineSight Points and Polylines

• Exporting to MineSight

Importing MineSight Points and Polylines

Discover>Import and Export>MineSight SRG Import

Polyline and point files exported from MineSight are in an ASCII, CSV format. The MineSight file has an SRG extension and contains fields: Easting, Northing, Elevation, Node Point count, Material name, Attribute name, Object Name, and Attributed Material name. The Easting, Northing, Elevation and Node Point count are required items.

To import a MineSight SRG file:

1. On the Discover menu, point to Import and Export, and then click MineSight SRG Import.


The Advanced ASCII Import tool automatically recognises the SRG file structure and makes the relevant selections. To modify the automatic assignments, see ASCII Data.

2. Click Import.


Example MineSight SRG file:

2733.330,5507.240,420.000,1,TOE,,TOE,2736.520,5502.470,420.000,2,TOE,,TOE,2730.110,5490.940,420.000,3,TOE,,TOE,2727.920,5479.010,420.000,4,TOE,,TOE,2740.690,5472.920,420.000,5,TOE,,TOE,2754.040,5480.850,420.000,6,TOE,,TOE,

Exporting to MineSight

Discover>Import and Export>MineSight SRG Export

To export a MapInfo table as a MineSight SRG file:

1. On the Discover menu, point to Import and Export, and then click MineSight SRG Export.

The MineSight Export Dialog Box is displayed.


3. In the Output SRG file box, type or edit the output file name, or click the browse button to navigate to the output folder and file.

4. Select the Flip XY check box to reverse the order of the X and Y coordinates.






For more details, see Reference Manual: MineSight Export Dialog Box.

Surpac

The Surpac Import utility enables you to import Surpac® ASCII string files into MapInfo tables. The data can either be imported as points representing each vertex in the string file or as strings (polylines). If you have a binary Surpac string file you will need to convert it to an ASCII format file before importing it into Discover.

MapInfo files can be exported in Surpac string format so they can be read directly into Surpac.

• Importing Surpac Strings

• Exporting to Surpac

Importing Surpac Strings

Discover>Import and Export>Surpac String Import

Surpac ASCII string files consist of a comma delimited header row and a coordinate definition row followed by data blocks representing each string in the file. Each string is separated by row of zeros. The Header File line consists of 4 fields separated by commas. The order of these fields is: the file location, the file date, the file description, the name of the associated string styles file.


Example Surpac string file:

lev,21-Mar-01,,ssi_styles:stylesam.ssi0, 0.000, 0.000, 0.000, 0.000, 0.000, 0.00010, 3571.951, 5778.637, 9991.767, 10, 3568.500, 5777.694, 9992.258, 10, 3563.795, 5777.088, 9992.910, 10, 3560.255, 5777.434, 9993.444, 10, 3559.546, 5777.745, 9993.561, 10, 3560.346, 5780.250, 9993.330, 0, 0.000, 0.000, 0.000,10, 3556.639, 5782.807, 9993.623, 10, 3554.921, 5781.819, 9993.826, 10, 3554.277, 5781.922, 9993.879, 0, 0.000, 0.000, 0.000,

Discover ignores the Surpac header and coordinate definition rows during import and instead creates a fixed format table to store the data. The default columns named used by Discover are String_Num, Group_Num, Z, X, Y. Depending on the structure of the file there may also be additional Attribute columns which contain additional information contained in the source string file. Each attribute column will be assigned a numeric index to represent different fields in the source file.

To import a Surpac string file:

1. On the Discover menu, point to Import and Export, and then click Surpac String Import.

The Surpac String Import Dialog Box is displayed.

2. Next to the Input string file box, click the browse button and select the input file.


4. In the Create Object type box, choose the object type.

5. Select the Flip XY check box to reverse the import order of the X and Y coordinates. Discover assumes that the input Surpac file lists coordinates in Y, X order.





For more details, see Reference Manual: Surpac String Import Dialog Box.

Exporting to Surpac

Discover>Import and Export>Surpac String Export

To export a MapInfo table as a Surpac string file:

1. On the Discover menu, point to Import and Export, and then click Surpac String Export.

The Surpac String Export Dialog Box is displayed.


3. In the Output string file box, type or edit the output file name, or click the browse button to navigate to the output folder and file.

4. Select the Flip XY check box to reverse the order of the X and Y coordinates. By default, the coordinates are created in Y, X order.





For more details, see Reference Manual: Surpac String Export Dialog Box.


Vulcan

The Vulcan Archive Import utility enables you to import Vulcan® Archive ASCII files into MapInfo tables. The data can either be imported as points representing each vertex in the string file, strings (polylines) or as closed strings (polygons).

MapInfo files can be exported in Vulcan Archive ASCII format so they can be read straight into Vulcan.

Importing Points and Polylines

Discover>Import and Export>Vulcan Archive Import

To import a Vulcan archive file:

1. On the Discover menu, point to Import and Export, and then click Vulcan Archive Import.

The Vulcan Import Dialog Box is displayed.

2. Next to the Input file box, click the browse button and select the input file.


4. In the Create Object type box, choose the object type.




For more details, see Reference Manual: Vulcan Import Dialog Box.

Note The X, Y coordinate values will not be imported into the browser and the Z value will be an average of the vertex Z values for each string in the original file because MapInfo does not support multiple vertex records per object in a browser.


Exporting to Vulcan

Discover>Import and Export>Vulcan Archive Export

To export a MapInfo table as a Vulcan archive file:

1. On the Discover menu, point to Import and Export, and then click Vulcan Archive Export.

The Vulcan Export Dialog Box is displayed.

2. Under File details, click the Input file box and select the table to be exported.

3. In the Output file box, type or edit the output file name, or click the browse button to navigate to the output folder and file.

4. In the Name field box, select the column assigned to the Name field (HoleID, for example) in the output file.

5. In the Value field box, select the column assigned to the Value field in the output file.

6. In the Z field box, select the field that defines the elevation, or select the Use fixed Z value check box and type the elevation in the adjacent box.




For more details, see Reference Manual: Vulcan Export Dialog Box.

Import, Reproject and Convert Vector Files

Discover>Import and Export>Transform Vector File

The Transform Vector File utility enables the transformation and reprojection of vector objects. It also enables a large range of vector formats to be imported and converted.

The Transform Vector File utility can handle a large range of vector file formats:


• MapInfo Professional .TAB

• MapInfo Professional .MIF

• ESRI shapefiles .SHP

• AutoCAD .DXF

• Gemcom .BT2

• ESRI .TIN, .ADF

• Surpac .DTM

• GOCAD vector .TS, .PL, .VS

• Datamine wireframe .DM

• Vulcan triangulation .00T

• 3D Studio files .3DS

The tool can be used to convert between file formats (with or without transformation and/or reprojection) by assigning the desired format with the Save File button at the base of the dialog. The following vector formats can be created:

• MapInfo Professional .TAB

• MapInfo Professional .MIF

• ESRI shapefiles .SHP

• AutoCAD .DXF

• .CSV file

• Encom Model Vision format .TKM


The Transform Vector File dialog

A range of Transformation options are available as independent X, Y and/or Z operations, allowing vector objects to be scaled, offset and/or rotated.

Vector files can also be Reprojected to accommodate absolute coordinate handling in Discover 3D. For instance, if all of your MapInfo data is in a UTM projection, but an ore body DXF model from a CAD program is in a different projection, this option will enable the DXF to be reprojected into the same projection as the rest of the 3D data. Enable the Reproject Coordinates option, and set the appropriate Source and Target projections using the Choose buttons.


Raster Imagery

Discover provide supports a number of different located image formats (see Reference Manual: Supported Data File Formats) and tools for importing and exporting raster imagery:

• Rectifying Raster Images

• ECW/JPEG2000

• Encom EGB

• Saving a Map Window as a Registered Raster Image

Rectifying Raster Images

Use Images>Rectify Image to import and register other types of raster imagery. For more information, see Registering and Rectifying Raster Images.

See also...Importing an EGB Image...ECW/JPEG2000...Saving a Map Window as a Registered Raster Image

ECW/JPEG2000

Discover>Import and Export>ECW/JPEG2000 Import

Use the Discover ECW/JPEG2000 import tool to import an ECW or JP2 located image and register it correctly in MapInfo Professional.

You can also load and open images from an ECWP or IWS image server. When processed, this generates both a TAB and an IWS file on the local disk. The IWS is a metadata file containing details about the Image Web Server ECWP link.

In addition, this tool also enables you to load and open ECWP (ECW protocol) images from an Image Web Server (IWS) URL (Universal Resource Locater) location. ECWP files are defined by a URL that starts with a ecwp:// prefix.

ECWP Image web servers can be found via the internet, or on local database servers. There is a number of free access and subscription based websites which provide access to ECW imagery databases via the internet.


When ECWP file is opened in Discover, a local TAB file and a local metadata link file with the extension IWS is created. The IWS file contains information such as the URL location of the ECWP file.

To open a local ECW/JP2 image file:

1. On the Discover menu, point to Import and Export, and then click ECW/JPEG2000 Import.

The Open ECW/P or JP2 Image Dialog Box is displayed.

2. Under Open, select Open .ECW or .JP2 file. to open a file from the local disk or network.

3. Click the Open button and select an image file to open. The image is displayed under Preview and its details are displayed under Image properties. Use the preview toolbar to examine the image.

4. If an appropriate projection is found in the image file, this will be automatically set and displayed in the Image Projection box, otherwise click the browse button next to the Map Projection box and select a MapInfo projection. Do not override the projection defined in the input file; instead, import the file, and then use Images>Reproject Image to reproject the image.

5. Check the dimensions of the Image in Columns x Rows, and further information can be found under the Information button.


6. Select the Raster grid handler.

7. Click Open.

To open an ECW/JP2 image file from an Image Server:

1. On the Discover menu, point to Import and Export, and then click ECW/JPEG2000 Import.

The Open ECW/P or JP2 Image Dialog Box is displayed.

2. Under Open, select Open file from Image Server.

3. Type or paste the URL link in the text box. Make sure to include the ecwp:// prefix.

4. Click the Load button to open the ECWP link in the preview area.

5. If an appropriate projection is found in the image file, this will be automatically set and displayed in the Image Projection box, otherwise click the browse button next to the Map Projection box and select a MapInfo projection. Do not override the projection defined in the input file; instead, import the file, and then use Images>Reproject Image to reproject the image.

6. Check the dimensions of the Image in Columns x Rows, and further information can be found under the Information button.

7. Select the Raster grid handler.

8. Click Open. You are pormpted to select an output file name and location. When processed, this generates both a TAB and an IWS file on the local disk. The IWS is a metadata file listing details about the Image Web Server ECWP link.

See also...Reference Manual: Discover>Import and Export>ECW/JPEG2000 Import...Importing an EGB Image...Rectifying Raster Images...Reprojecting an Image...Converting an Image to Another Format

Note ECW/JPEG2000 grids are not supported by the Discover Surfaces module.


Encom EGB

• Importing an EGB Image

• Exporting as an EGB Image

Importing an EGB Image

Discover>Import and Export>Encom PA Located Image Import

Discover can automatically import EGB (Encom Georeferenced Bitmap) files created in Encom PA or Discover 3D. EGB files are text header files that are used to open and display image files such as *.BMP, *.JPG and *.PNG in 3D georeferenced space.

Example Encom Georeferenced Bitmap (EGB) file:

GeoreferenceImage Begin Comments = "" Version = "1.0" Image = "Kangaroo_Flats_Geochem_Map.png" ImageFormat = PNG Geometry = QUAD CoordinateSpace Begin Projection = "Transverse Mercator (Gauss-Kruger)" Datum = "Australian Geodetic 1966 (AGD 66)" Units = "km" CoordinateSpace End Registration Begin TopLeft = 373570,5380784.86,0 TopRight = 400692.53,5380784.86,0 BottomLeft = 373570,5356994.78,0 BottomRight = 400692.53,5356994.78,0 Registration EndGeoreferenceImage End

To import an EGB located image:

1. On the Discover menu, point to Import and Export, and then click Encom PA Located Image Import.

The EGB Import Dialog Box is displayed.

2. Under File details, next to the Input EGB file box, click the browse button and select the input file.


3. In the Output TAB file box, type or edit the output table name, or click the browse button to navigate to the output folder and file.

4. If a transparent colour is defeined in the input file, select Use transparent colour from EGB.

5. Click Set Projection and choose the projection that the image coordinates were created in.

6. If required, under Coordinate Transform, reassign the X and Y coordinates. For example, you can map the Z field in a vertical section as the Y field in the map window.


For more details, see Reference Manual: EGB Import Dialog Box.

See also...ECW/JPEG2000...Rectifying Raster Images

Exporting as an EGB Image

Discover>Import and Export>Encom PA Located Image Export

MapInfo files can be exported as EGB (Encom Georeferenced Bitmap) files so they can be read straight into Encom PA or Discover 3D. The MapInfo map window is converted into a PNG file with an associated EGB (Encom Georeferenced Bitmap) header file.

To export a map window as an EGB located image:

1. On the Discover menu, point to Import and Export, and then click Encom PA Located Image Export.

The Export Map to Encom PA Dialog Box is displayed.

2. Under Windows available for export, select the map window to be exported.

3. In the Height for Z axis box, type the elevation (Z) in metres.


Exporting Drillhole Sections as EGB Images

You can also export sections and plans from a Discover drillhole project using Drillholes>Import or Export>Export Located Bitmap for Encom PA. This will correctly register a plan or cross-section in 3D.

See also...ECW/JPEG2000...Rectifying Raster Images

Saving a Map Window as a Registered Raster Image

Use Discover>Map Window>Convert Map to Registered Raster to save a map window as a registered raster image. For more information, see Saving a Map Window as a Registered Raster Image.

See also... Importing an EGB Image...Exporting as an EGB Image...ECW/JPEG2000...Rectifying Raster Images

Surface Grids

Use MapInfo Professionals File>Open option to import the following grid file types, and set the Files of Types to Grid Image:

• BIL Grid

• ER Mapper Grid

• ESRI ASCII Grid

• Geosoft Grid

• Minex Grid

• Surfer Grid


• USGS DEM Grid

The formats above can also be imported from the Surfaces>Import Grid File menu (see Alternative Grid Import Tools); however, File>Open is the recommended method.


Use Discover Surfaces>Import Grid File menu to import the following grid file types:

• ASCII Grid

• HGT Grid

Use Discover Surfaces>Export Grid File menu to export grids:

• Export Grid to ASCII File

• Export Grid

Other tools:

• Convert v2.1 Grids

• Toggle Support for Vertical Mapper Grid

ASCII Grid

Surfaces>Import Grid File>ASCII Grid

Discover can convert and register ASCII format grids, i.e. text file format, so they can be displayed and queried using the Discover Surfaces module. ASCII grid files may contain X, Y and Z values or just Z values only.


ASCII grid import dialog configured for an XYZ value format

To import an ASCII Grid:

1. Open the ASCII Grid Import dialog

2. Use the Browse button to select the ASCII grid File to Import (*.TXT, *.ACS or *.CSV formats)

3. The Output Grid will automatically be assigned with the same name as the input grid and default to the preferred grid format specified in Discover>Configuration>Grid Handlers. Both the saved grid name and saved grid type can be modified using the Browse button adjacent to the Output Grid control.

4. Use the File Format pull-down list to select whether the grid file contains X, Y and Z values or Z values only. The dialog options for these formats are discussed further below.

5. If there are null cell values used such as -9999 enter these into the Null cell value window.

6. Select a colour look-up table to display the grid once it is created from the Image Shading pull-down list.

7. Select the projection of the ASCII grid using the Map Projection button.


8. Select a Coord Type either the Cell Lower Left Corner or the Cell Center. This specifies at which point the XY coordinates refer to in each cell.

9. Press OK to complete the ASCII grid import process.

X Y Z values file format

XYZ ASCII files contain a row for each cell listing it’s X and Y coordinate information and Z value. In the Coord type control (bottom of the dialog), the XY coordinates must be specified as referring either to the Cell Centre or the Cell Corner point.

ASCII XYZ file displayed in a text editor

Z values only file format

If the ASCII grid file contains Z values only, the Import Properties dialog is automatically displayed requesting further grid information:


Import Properties dialog

The following information must be specified for a Z-values only grid:

• the number of rows and columns in the grid

• the origin (XY coordinates) of the grid

• the grid cell size.

Discover can automatically obtain this information if the grid to import is an ESRI ASCII Grid as the grid dimensions are stored in the Header of this grid file type. If the grid file does not contain a header the grid dimensions will need to be entered manually.

Discover also must know where to start importing the grid from and whether to import by row or column. When complete, click OK to return to the ASCII Grid Import dialog.


HGT Grid

Surfaces>Import Grid File>HGT Grid

NASA Shuttle Radar Topography Mission (SRTM) data is available in a binary height file format (*.HGT). Discover’s HGT Importer imports both 1 and 3 arc-second HGT files as ERMapper grids for use in the MapInfo environment.

To import a HGT file:

1. From within the tool, first select the appropriate arc-second size (1 or 3 seconds).

2. Press Process files, and select one or more HGT files to import. Press OK to generate the necessary ERS header and TAB file/s

3. Close the dialog, and use MapInfo’s File>Open to browse for the newly created TAB files. Open these.

A source of HGT grid files is NASA’s FTP site at ftp://e0srp01u.ecs.nasa.gov/srtm/version2/. This has both SRTM1 (1 arc-second) data covering the US and its territories and possessions, and SRTM3 (3 arc-second) data covering the world.

Alternative Grid Import Tools

The formats below can be imported from the Surfaces>Import Grid File menu; however, File>Open is the recommended method for these formats.

• BIL Grid

• ER Mapper Grid

• ESRI ASCII Grid

• Geosoft Grid


• Minex Grid

• Surfer Grid


• USGS DEM Grid

The Discover Surfaces>Import Grid File option provides a method that enables the user to check the grid header file during the import process.

When importing the grid files Discover will attempt to read the grid geometry information from the grid file header. If Discover cannot access the grid geometry information it will check the grid file size, the number of cells and the cell size to ensure that the grid geometry is valid. Modify or enter any additional information necessary in the registration dialog. When importing a grid using Discover specify an appropriate MapInfo Projection for the grid file so it can be correctly registered.

When a grid is imported into MapInfo, a .TAB file is created that defines the filename, format (“raster”) and the origin and extents of the data. The coordinate system and projection information is also specified.

When a grid is imported into MapInfo, a .TAB file is created that defines the filename, format ("raster") and the origin and extents of the data. The coordinate system and projection information is also specified. The TAB file also contains metadata relating to the statistics and colour applied to the display of the grid in MapInfo. The following is an example TAB file containing grid display metadata for an ER Mapper grid:

!table!version 500!charset WindowsLatin1

Definition Table File "png_compositesrtm.ers" Type "RASTER" (128.999583333333,0.000416638889) (0,0) Label "Pt 1", (155.000415626633,0.000416638889) (31201,0) Label "Pt 2", (128.999583333333,-11.000416254411) (0,13201) Label "Pt 3", (155.000415626633,-11.000416254411) (31201,13201) Label "Pt 4" CoordSys Earth Projection 1, 104 Units "degree" RasterStyle 6 1begin_metadata"\Encom" = """\Encom\Grid" = """\Encom\Grid\Display" = ""


"\Encom\Grid\Display\Min Cell Value to Colour" = "-60.00000000000""\Encom\Grid\Display\Type" = "3""\Encom\Grid\Display\SunElevation" = "60.0""\Encom\Grid\Display\Max Cell Value to Colour" = "4805.000000000""\Encom\Grid\Display\Colouring" = """\Encom\Grid\Display\Colouring\InterpolateColor" = "1""\Encom\Grid\Display\SunHighlightElevation" = "60.0""\Encom\Grid\Display\MaxCellValue" = "4805.0000000000""\Encom\Grid\Display\SunIntensitySaturation" = "100.0""\Encom\Grid\Display\SunColorSaturation" = "0.0""\Encom\Grid\Display\SunAzimuthDeg" = "45.0""\Encom\Grid\Display\SunHighlightIntensity" = "40.0""\Encom\Grid\Display\SunHighlight" = "0""\Encom\Grid\Display\SunHighlightAzimuth" = "315.0""\Encom\Grid\Display\SunHighlightSaturation" = "0.0""\Encom\Grid\Display\LUT" = "pseudocolor.lut""\Encom\Grid\Display\MinCellValue" = "-60.000000000""\Encom\Grid\Display\SunShadowDepth" = "50.0""\Encom\Grid\Display\SunShading" = "0""\IsReadOnly" = "FALSE"end_metadata

BIL Grid

Surfaces>Import Grid File>BIL Grid

The Band Interleaved by Line (BIL) format for storing gridded surface data is a popular format and is readable by many other software packages, such as ER Mapper and Arc/Info. The BIL format simply stores each grid cell value sequentially starting at the upper left and proceeding by row towards the lower right. The geometry of the BIL grid file is defined in an associated .HDR file (that states the number of rows and columns as well as other information).

The BIL format used by Discover allows grid cells of any values to be stored, as well as null cell values (grid cells that do not have an interpolated value). Discover can also read BIL files created in other software and on UNIX workstations.

Discover can automatically register BIL grids (and the corresponding .HDR file) using the information in the .HDR file. For the grid to register correctly select an appropriate MapInfo projection using the CoordSys button to correspond with the coordinate system of the BIL file.


BIL Grid import parameters with selected projection

ER Mapper Grid

Surfaces>Import Grid File>ER Mapper Grid

The ER Mapper software image/grid format is described in detail in the ER Mapper Open Standards documentation. The grid format is unchanged from Versions 3.x, 4.x, 5.x and 6.x of ER Mapper. The standard raster image that may be displayed by ER Mapper software can be imported as a Discover grid. The image/grid is actually defined by two files, a header (.ERS file) plus a binary data file. The content of the .ERS file is defined in ER Mapper documentation but an example is shown below:

DatasetHeader BeginVersion= '5.5'LastUpdated= Thu Mar 3 23:38:11 GMT 1995SensorName= 'GEOTEM'SenseDate= Fri Nov 19 06:07:58 GMT 1996DataSetType= ERStorageDataType= RasterByteOrder= MSBFirstCoordinateSpace BeginDatum= 'AGD66'


Projection= 'TMAMG53'CoordinateType= ENUnits= 'METERS'Rotation= 0:0:0.0CoordinateSpace EndRasterInfo BeginCellType= Signed32BitIntegerNullCellValue= -9999999CellInfo BeginXdimension= 50Ydimension= 50CellInfo EndNrOfLines= 128NrOfCellsPerLine= 320RegistrationCoord BeginEastings= 327600Northings= 8595050RegistrationCoord EndNrOfBands= 2BandId BeginValue= 'Channel 16'Units= 'ppm'BandId EndBandId BeginValue= 'Channel 3'Units= 'ppm'BandId EndRasterInfo End

DatasetHeader End


ER Mapper Grid import parameters with selected projection

Discover automatically registers an ER Mapper dataset (an .ERS file and accompanying grid file). Select the appropriate coordinate system using the CoordSys button and the registration dialog displays the information from the ER Mapper header file.

Note When ER Mapper grids are created by Discover the Datum and Projection variables in the .ERS file are NOT set to the projection of the input data points. Instead the Datum and Projection fields are set to RAW, RAW by default. To open an .ERS grid which has been created by Discover in ER Mapper these variables must be edited and replaced with the correct ER Mapper Projection and Datum variables that equate to the projection of the original point data used by Discover. If the RAW, RAW variables are not replaced with the correct Projection & Datum information the .ERS file will not open in ER Mapper 6.0 or later.

Note Any *.ERS files created as a virtual dataset are not registered.


ESRI ASCII Grid

Surfaces>Import Grid File>ESRI ASCII Grid

Discover can automatically register ESRI ASCII grids, so they can be displayed and manipulated using the Discover Surfaces module.

The structure of ESRI ASCII grid file (opened in a text editor).

ESRI ASCII grids generally have a six line header at the beginning of the file which contains information relating to the number of rows and columns in the grid, the lower left hand corner X and Y coordinates, the grid cell size and the null data value. Each entry under the header represents the z value of a grid cell. The order of the data is from left to right along each row at a time.

To import an ESRI ASCII grid:

1. Open the Import ESRI ASCII grid dialog by selecting the Surfaces>Import Grid Files>ESRI ASCII Grid menu option.

2. Use the Browse button to navigate to and select the target grid. The importer will automatically detect the ESRI ASCII grid geometry and populate the dialog with the correct details.

3. By default the grid projection will not be defined. Click on the Projection button and choose the correct projection for the grid.

4. To import the grid into MapInfo click the OK button.


The ESRI ASCII Grid Importer Dialog

Geosoft Grid

Surfaces>Import Grid File>Geosoft Grid

The Geosoft binary grid format is composed of two elements:

• a 512 byte grid header

• the grid/image data

Specific details of the contents of these files can be obtained from Geosoft (Toronto, Canada). Some revisions of the grid format have been made and the import utility within Discover has been established to comply with the grid format current as of March 2000.

When importing a Geosoft grid select an appropriate MapInfo coordinate system using the CoordSys button to enable the Geosoft grid to be correctly registered.

Note Discover supports both uncompressed and compressed Geosoft Grids


Geosoft Grid import parameters with selected projection

Minex Grid

Surfaces>Import Grid File>Minex Grid

Discover has the facility to Import Minex Grid files. The Minex .XYZ grid format is typically used in Surpac Minex software package for the display of 3D surfaces. The Minex Grid utility is capable of importing multi-banded .XYZ datasets.


Typical Minex XYZ Grid ASCII data format

The geometry of the Minex grid is defined in the header of the grid file:

• Origin - Grid origin located at the lower left grid cell centre

• Extent - Refers to the dimensions of the grid

• Mesh - Size of the grid cells

• Rotation - Rotation applied to the grid.

• X and Y - Start position and length for X and Y data values

• Band* - Start position and length for each data band.

To import a Minex grid, navigate to Surfaces>Import Grid Files>Minex Grid menu option.

Note The Minex utility is not currently designed to display rotated grids upon import. To rotate a grid after it has been imported use the Surfaces>Grid Utilities>Rotate tool. Although Discover can import multi-banded Minex grids, the grid will not be separated into its component bands on import. To separate a multi-banded grid, use the Discover>Surfaces>Grid Utilities>Split utility.


Minex Grid Importer Dialog

In the Import Minex grid dialog use the Browse button to navigate to the folder where the grid file is located and select the grid.

The importer will automatically detect the Minex grid geometry and populate the dialog with the correct details. If you wish to alter the grid registration this can be done within the Import Minex Grid dialog.

By default the grid projection will not be defined. Click on the Projection button and choose the correct projection for the grid.

To import the grid into MapInfo click the OK button.

Surfer Grid

Surfaces>Import Grid File>Surfer Grid

Discover supports the Surfer GS Binary Grid file format. These grid files have a .GRD file extension. When importing a Surfer GS Binary grid Discover will automatically determine the grid dimensions and grid geometry. The projection in which the grid was originally created must be known prior to import as the Surfer binary grid format does not contain any coordinate system information.

When importing a Surfer grid select an appropriate MapInfo coordinate system using the CoordSys button to enable the Surfer grid to be correctly registered.


Surfer Grid import parameters with selected projection

Surfer ASCII grids may be imported using the Import ASCII Grid option but will need to be modified to conform to standard ASCII grid import format. Any header information would need to be removed from the file and the grid then imported using the ASCII Grid Import Z-values only option. The number of grid rows and columns, the grid origin and grid cell size information from the original header information will need to be entered manually.

Vertical Mapper Grid

Surfaces>Import Grid File>Vertical Mapper Grid

Vertical Mapper grids are supported in MapInfo Professional 5.5 or later as read only files. A Vertical Mapper grid is a binary format grid with the file extension default of .GRD. Vertical Mapper can export a number of different grid formats including ASCII grids.

Discover includes a read/write Grid Handler for Vertical Mapper format grids so they can be read and modified by the Discover Surfaces utilities. An appropriate MapInfo coordinate system must be selected using the CoordSys button to enable the Vertical Mapper grid to be correctly registered.


Vertical Mapper Grid import parameters with selected projection

In order to modify a grid created by Vertical Mapper using Discover the Vertical Mapper grid file must be “toggled on” within Discover. See Surfaces>Import Grid File>Toggle Support for Vertical Mapper Grid for more information.

For information on the formats of each of the above, refer to the Vertical Mapper User Guide.

USGS DEM Grid

Surfaces>Import Grid File>USGS DEM Grid

The United States Geological Survey (USGS) provides Digital Elevation Model (DEM) data across the entire United States. One of the formats which is provided free of charge to the general public is DEM data captured at 1:24,000 or 7.5 minute scale. This 1:24,000 scale provides elevation data in 30 x 30 meter spacings with each DEM tile corresponding to the USGS 7.5 minute topographic quadrangle map series for the United States.

Note When a Vertical Mapper grid is associated with Discover the grid will not be able to be modified in Vertical Mapper until the format handling is toggled back to Vertical Mapper. This is done by re-selecting the Surfaces>Import Grid File>Toggle Support for Vertical Mapper Grid menu option.


1:24,000 scale DEM data is available in SDTS format only. Spatial Data Transfer Standard (SDTS) format is a standard industry file format used to share or transfer spatial data between different computer systems. The 1:24,000 DEM data files in SDTS format can be downloaded from GIS Data Depot http://gisdatadepot.com/dem, from MapMart.com at www.mapmart.com, and from Advanced Topographic Development and Images (ATDI) at www.atdi-us.com.

Once the appropriate DEM file is selected from one of the websites listed above, download both the DEM data file and the corresponding text file to your computer. The DEM dataset is made up of a number of files which have been packaged together as a .TAR archive file and then saved using the gzip compression format. For example, the Bear Hole 1:24,000 DEM from Big Horn county, Montana download file is named 1630650.DEM.SDTS.TAR.GZ. The corresponding 1630650.DEM.SDTS.TXT file can be opened using any text editor such as WordPad, NotePad, etc and contains information about the DEM data including cell size, grid origin and projection information which will be required in order to import the DEM data successfully.

In Windows Explorer open the 1630650.DEM.SDTS.TAR.GZ file using WinZip or an equivalent zip file software application. A message similar to the following should appear:

The Discover USGS DEM import utility uses the contained .TAR file to import, extract and display the DEM data. Therefore do not decompress the contents of this file to a temporary folder and open it but click “NO” in order to display the contents of the 1630650.DEM.SDTS.TAR.GZ file in WinZip:

http://www.mapmart.com


http://www.atdi-us.com

http://gisdatadepot.com/dem




1. Copy this zipped 1630650.dem.sdts.tar file into a folder in Windows Explorer. The DEM data is now ready to import using Discover.

2. Select Import Grid File>USGSDEM Grid from the Discover>Surfaces menu.

3. Browse to the folder in Windows Explorer containing the DEM .TAR file and click Open.

The Discover USGSDEM Grid Registration dialog is displayed with the number of columns and rows, the top left X and Y grid coordinates and the cell height and width already populated.


Click on the CoordSys button and select the correct projection. The 1:24,000 DEM grids are generally in the Universal Transverse Mercator (NAD 27 for US) projection and the correct zone information can be found in the corresponding TXT file discussed earlier. Click OK to create the grid. The DEM grid is displayed in grey scale in a new map window and can be used with any of the Discover Surfaces grid menu options and tools. To re-open the USGS DEM grid simply select the .TAB file in the MapInfo File>Open dialog.

Convert v2.1 Grids

Surfaces>Import Grid File>Convert v2.1 Grids

Versions 2.0 and 2.1 of Discover created BIL grids in 8-bit per cell format. Whilst these grids still display with no problems they cannot be used for grid analysis (profiles, contours etc.) with later versions of Discover. The old grid file is overwritten unless it is a read-only file.

Toggle Support for Vertical Mapper Grid

Surfaces>Import Grid File>Toggle Support for Vertical Mapper Grid

Use the Toggle Support for Vertical Mapper Grid menu item to associate a Vertical Mapper grid with Discover. Once a Vertical Mapper grid has been associated with Discover, the grid cannot be used within Vertical Mapper until the toggle is turned off. Turn off the toggle by re-selecting the Toggle Support for Vertical Mapper Grid menu.


Export Grid to ASCII File

Surfaces>Export Grid File or Contours>Export Grid to ASCII File

There may be instances where a Discover grid is to be used with other software that cannot read binary grids. In this case, the safest way to transfer the grid is in ASCII format. Discover provides the option of exporting the grid as either XYZ values or Z values only per line. It can also create an ESRI ASCII grid file.

The following parameters can be set in the ASCII Grid Export dialog:

• Grid Origin – specifies the location of the first cell written to the file. The grid will be written sequentially from this point.

• Cell Origin – sets whether the XY co-ordinates refer to the cell centre or lower-left corner point.

• Export by – sets whether the file will be written row-by-row or column-by-column.

• Delimiter – the value delimiter method used in the file (e.g. tab, comma, etc) .

• Null Cell Value – value written for null cells – this overrides any inherent null value in the grid.

• Precision – precision of numbers written to the file.

Note for ESRI ASCII export format, only the Cell Origin, Null cell value and Precision options are available.

Export Grid

Surfaces>Export Grid File or Contours>Export Grid

Discover can convert (export) any supported grid to an alternative grid format. This allows a grid created in Discover to be used with another software packages.

This menu option opens the grid Convert Tool; this can also be accessed from Surfaces>Grid Utilities.

Note When exporting to the ESRI ASCII format, only the Cell Origin, Null cell value and Precision options are available.


Drillholes

• Discover Drillhole Projects

• gINT

• WinLoG

Discover Drillhole Projects

Drillhole projects can be imported and exported to allow transfer of projects to other computers or for archiving of projects.

Discover Drillhole Project DXP File

When a drillhole project is exported from Discover, all related files, including the downhole colour look-up tables, section definition files, collar, survey, downhole data tables, and section-specific downhole data display settings templates are exported. All exported drillhole project files are copied to a single directory along with a newly created .DXP file. The .DXP file is a drillhole project marker file that is used to import the project on another computer. When the drillhole project files have been copied, the entire contents of the export directory can be zipped and sent to other users or can be archived.

To export a Discover drillhole project:

• On the Drillholes menu, point to Import or Export, and then click Export Discover Drillhole Project.

If transfering to a pre-version 10 installation of Discover, use Export Discover Drillhole Project in Pre-Version 10 Format.

To import a Discover drillhole project:

1. On the Drillholes menu, point to Import or Export, and then click Import Discover Drillhole Project.

2. Select the .DXP file.

The drillhole project is added to the current drillhole project list and any colour look-up tables and other data are appended to their respective tables.

Note Export Discover Drillhole Project tool does not support the Project Session functionality (see Saving and Restoring Drillhole Sessions)


See also...Reference Manual: Import or Export Menu (Drillholes)

gINT

Drillholes>Import or Export>gINT Importer

The gINT® product suite encompasses software for creation of borehole, well log and fence diagrams, amongst other things. Bundled with Discover is an easy to use importer which converts data stored in the gINT® database format into the necessary MapInfo tables required for a Discover drillhole project, and optionally automatically creating a drillhole project.

To import data from a gINT database:

1. On the Drillholes menu, point to Import or Export, and then click gINT Importer.

The gINT Importer Dialog Box is displayed.

2. Under Input gINT project database file, if you have previously imported this database and saved the import settings as a template, click Open Template and select the template. Otherwise, click the Open button and browse to the .GPJ file to be imported.

If you have selected a template, review the table and field assignments on the Collar Settings and Downhole Data Settings tabs, and then click OK to start the import. Otherwise, for a new database import, follow the instructions below.

3. On the Collar Settings tab, under Collar table, click Projection and choose the projection that the collar coordinates were recorded in.

4. Under Collar fields, review the field assignments.

5. On the Downhole Data Settings tab, use the controls to move the required data table to the Selected box.

When a table is selected, the Downhole Field Assignments Dialog Box is displayed, from which you can assign the hole ID, depth fields, and data fields. Note that:

• For downhole depth measurements, assign the depth field in both the Top Depth (From) and Bottom Depth (To) boxes. The importer will automatically create two separate output fields.


• Required fields, such as sample depths and borehole number, cannot be deselected.

Field assignment examples for depth (e.g. geophysics) and interval (e.g. Lithology) data (left and right examples respectively).

To review and edit field assignments, double-click the table in the Selected box, or select the table and click Set Field Mappings.

6. Under Output options, click the Save button and select the folder where the new MapInfo drillhole tables will be created.

7. To create a new Discover drillhole project (recommended), select the Create Discover project check box and type a project name in the adjacent box. To overwrite or refresh an existing drillhole project, select the project name from the list and ensure that the output folder specified in the Directory box matches that of the target project.

Note Updating an existing project will not update any sections or plans. These will need to be refreshed and regenerated.


8. Use the Save Template button to save your import settings so that you can quickly re-import an updated version of this database using the Open Template option (see step 2).


If a drillhole project was created by the import, select Drillholes>Project Setup to open the new project and review the project settings.

See also...Reference Manual: Import or Export Menu (Drillholes)...Modifying and Deleting Drillhole Projects...Refresh Downhole Data...Regenerate Sections

WinLoG

Drillholes>Import or Export>WinLoG Import

WinLoG is a well-logging application used in the environmental and hydrogeology fields. Discover can easily import a WinLoG database, converting the data into the necessary MapInfo tables required for a Discover drillhole project, and optionally automatically creating a drillhole project.

Before importing a WinLoG database, you need to know the following:

• The projection of the collar co-ordinates.

• Are all the wells/bores vertical, or does the database contain some inclined holes? WinLoG calls these “deviated” boreholes.

• Which downhole data tables within the WinLoG database are to be used, and which fields in each table are required. WinLoG stores data in a standard Access database (.MDB) structure, regardless of what downhole data was input. Therefore every WinLoG database will have exactly the same standard tables and table structure (e.g. Lithology, Geophysics_Data, Samples, Water_Data, etc), even if these tables are empty.

To import data from a WinLoG database:

1. On the Drillholes menu, point to Import or Export, and then click WinLoG Import.

The WinLoG Importer Dialog Box is displayed.


2. Under Input WinLoG project database file, if you have previously imported this database and saved the import settings as a template, click Open Template and select the template. Otherwise, click the Open button and browse to the .MDB file to be imported.

If you have selected a template, review the table and field assignments on the Collar Settings, Survey Settings, and Downhole Data Settings tabs, and then click OK to start the import. Otherwise, for a new database import, follow the instructions below.

3. On the Collar Settings tab, under Collar table, click Projection and choose the projection that the collar coordinates were recorded in.

4. Under Collar fields, review the field assignments.

5. If the database consists entirely of vertical holes or wells, you can skip the Survey Settings tab. The WinLoG Importer will automatically create the necessary Dip and Azimuth fields required by the Discover Drillhole module and set these values at 90 and 0 degrees respectively.

If the database contains any inclined holes (WinLoG version 4 and later), on the Survey Settings tab, under Borehole survey table, select Assign a separate downhole survey table for angled holes. Tthe WinLoG DeviationSurvey table is automatically converted for use in Discover.

6. On the Downhole Data Settings tab, use the controls to move the required data table to the Selected box.

When a table is selected, the Downhole Field Assignments Dialog Box is displayed, from which you can assign the hole ID, depth fields, and data fields. Note that:

• For downhole depth measurements, assign the depth field in both the Top Depth (From) and Bottom Depth (To) boxes. The importer will automatically create two separate output fields.

• Required fields, such as sample depths and borehole number, cannot be deselected.

Note WinLoG uses a dip of 0 degrees for vertical holes; these will be converted automatically to 90 degrees. Thus a WinLoG dip of 5.2 degrees will be converted to 84.8 degrees for use in Discover.


Field assignment examples for depth (e.g. geophysics) and interval (e.g. Lithology) data (left and right examples respectively).

To review and edit field assignments, double-click the table in the Selected box, or select the table and click Set Field Mappings.

7. Under Output options, click the Save button and select the folder where the new MapInfo drillhole tables will be created.

8. To create a new Discover drillhole project (recommended), select the Create Discover project check box and type a project name in the adjacent box. To overwrite or refresh an existing drillhole project, select the project name from the list and ensure that the output folder specified in the Directory box matches that of the target project.

Note Updating an existing project will not update any sections or plans. These will need to be refreshed and regenerated.


9. Use the Save Template button to save your import settings so that you can quickly re-import an updated version of this database using the Open Template option (see step 2).


If a drillhole project was created by the import, select Drillholes>Project Setup to open the new project and review the project settings.

See also...Reference Manual: Import or Export Menu (Drillholes)...Modifying and Deleting Drillhole Projects...Refresh Downhole Data...Regenerate Sections

4 Working with Tables 103

4 Working with Tables• Opening and Closing Tables

• Refreshing Tables with Database Connections

• Searching and Replacing Text in Tables

• Selecting Table Records

• Splitting Tables

• Digitizing and Data Entry

• Working with Multiple Tables

Opening and Closing Tables

• Opening Favourite Tables

• Opening Multiple Tables

• Closing All Tables

Opening Favourite Tables

The Favourite Tables tool enables frequently used tables to be added to a list where they can be opened and displayed quickly and easily. Instead of having to use File>Open to open tables each time, tables located in different folders or on different network drives can be opened from a single source. Favourite tables can also be assigned an "alias" name to make it easier to determine the contents of the table in the list if desired.


Favourites Dialog Showing Tables List

To add a favourite table:

1. Select Discover>Table Utilities>Favourite Tables.

3. Click File Open and browse to the location of the table to add.

4. Enter an alias name for the table into the Name window if desired.

5. Click OK.

6. Repeat steps 3 and 4 to add another table to the list.

2. Click the Add button.



To open Favourite Tables:

1. Select Discover>Table Utilities>Favourite Tables.

3. To select multiple tables click and drag with the mouse or hold down the SHIFT or CTRL keys.

4. Select a Preferred View from the following:

• New Mapper for All – Open the selected tables into a single map window

• New Mapper for Each – Open the selected tables into separate map windows

• Current Mapper – Open the selected tables into the current map window

• Browser – Open the selected tables as browser windows only

• No View – Open the selected tables but do not display them in a map or browser window

5. Click Open Tables.


Additional Options:

• Opening Multiple Tables

2. To open a single table select it from the list and double-click with the mouse or click Open Tables.

• To remove a table highlight it and click the Remove button.

• To edit a table name or location highlight it and click the Edit button.

• To re-order tables highlight the table in the list and click on the Up and Down arrow buttons.


Opening Multiple Tables

Discover>Table Utilities>Multi-File Open

Open many tables at once from a number of different folders.

The Multi-File Open is extremely useful when working with many tables. It is not uncommon for a user to want to open a number of tables from different folders and add them to a new map window. Rather than using the MapInfo File>Open Table menu option once for each different folder containing the desired tables, the Discover Multi-File options enable a user to choose all the tables from the one dialog.

Open Multiple Tables dialog


Select the disk drive from the Look in drop-down list. Browse through the folders in the drive until a desired folder is reached. Highlight the table(s) from the folder and click on the Add File button. The selected tables will then be displayed in the Selected Files window. Choose the mode of display from the Preferred View drop-down list. The available preferred views include opening all the selected tables into the one map window, each table into a separate map window, into a currently open map window, as browser windows or as no view. If all the tables to open are located within the one folder, click Open when all tables have been selected.

If some of the tables exist in other folders (or on another disk drive), change to the appropriate drive and folder. Select another table and use the Add File button to add this table to those already in the Selected Files window.

To remove a table from the Selected Files list make sure it is highlighted and then click on the Remove File button. When all the files to be used are selected, choose the Preferred View and click on the Open button.

Closing All Tables

Discover>Table Utilities>Close All

The MapInfo File>Close Table or File>Close All commands enable all or a selection of the currently open tables in the work session to be closed. In addition to closing selected tables from the currently open table list the Discover Close All command can also enable unused or query tables to be removed from the current work session.


Close All Dialog with Queries and Unused Tables highlighted

Hold down the SHIFT key or click and drag holding down the left mouse button to select consecutive tables from the list to close. Hold down the CTRL key to select non-consecutive tables.

Click the Unused button to close all tables which are open but not currently visible in a map or browser window. This option should be used before saving a workspace to close any unused tables open in the background. This should help to minimize problems with opening the workspace in the future if all unnecessary tables are removed prior to saving the workspace.

Click the Query button to close all tables created from map or browser window selections including queries created using the Query>Select or Query>SQL Select menu options.

Note If the Save Queries in Workspaces option in the Options>Preferences>Startup dialog is checked then any open query tables created using the Query>Select or Query>SQL Select will be written to a saved workspace. Remove unwanted queries using the Discover Close All command before saving the workspace.


Refreshing Tables with Database Connections

Discover>Table Utilities>DBMS Auto Refresh

The Discover DBMS Auto Refresh utility enables tables linked to a remote DBMS database such as SQL, Oracle or Access to be automatically refreshed at a specified time interval. This ensures that the most recent exploration or mining data is being used at all times with MapInfo. In order to use the DBMS Auto Refresh utility a remote database connection must be created and the database tables already open into MapInfo. See the MapInfo User Guide for more information on how to set up and work with remote database connections.

Select the DBMS Auto Refresh option from the Discover>Table Utilities menu. A new DBMS Auto Refresh menu is added to the MapInfo Menubar.

Click on the Settings option to display the Select Database Tables to Update dialog:


All of the DBMS currently open tables are displayed along with the remote database connection details including DSN name, database file path and driver information. Select the remote database tables to be updated automatically by clicking in the box next to each table or use the Select All button.

Specify an Update Interval Time in Minutes or Hours. Click OK to finish.

To start the automatic refresh, select Update On from the DBMS Auto Refresh menu. A tick will be placed next to this option when in update mode. Alternatively, turn on the automatic refresh by clicking on the Update On button.

To stop the automatic refresh, select Update Off from the DBMS Auto Refresh menu. A tick will be placed next to this option when not in update mode. Alternatively, turn off the automatic refresh by clicking on the Update Off button.

To refresh a database in between the scheduled automatic updates select the Refresh Now menu option or click on the Refresh Now button.

Note If a remote database table is closed during the automatic update session a warning message is displayed. To prevent warning messages being displayed for closed tables go to the Settings menu option to remove the tables from the update list or select the Update Off option to turn off the automatic refresh altogether.


Searching and Replacing Text in Tables

Discover>Data Utilities>Text Search and Replace

The search facility enables identification of selected records which contain specific words or characters. For example, select all sample numbers that contain the letters "SS" or all surveys that contain the word "Aeromagnetic". The text search may be case-sensitive but does not require that the whole word is entered. Discover will search selected fields for all records which contain the characters and return all records regardless of the other characters in the string.

To initiate a search, select the Discover>Data Utilities>Text Search and Replace option from the Discover menu or click the Text Search button. Select the table to search from the Select a Table dialog. The Text Search dialog is displayed.

Text Search dialog

Select the columns to search from the list. Click and drag holding the left-mouse button to select consecutive search columns or use the SHIFT key. Use the CTRL key to select non-consecutive search columns from the list.

Search one or more columns in a table for a particular text string with the option to replace each occurrence with a new string.


Choose the type of search from Find text only or Find and Replace selected text or whole string. All searches can be designated to find records according to case by checking the Case Sensitive search box. To view the selected records check the Browse Selection box. If this box is not checked a dialog will appear with information relating to how many records are found and/or replaced with the selected text.

Enter the entire text string or selected text characters from the search text string in the Find window. In the above example, Discover will search for all occurrences of the text "Riversleigh" in the Unitname field. The returned search records can also be replaced with new text if desired. Although the above search is performed on a character column, searches can also be made on numeric fields whereby Discover will search and/or replace the selected numerical data.

If a Find and Replace text search has been selected enter the replacement text in the Replace with window. For example, find all occurrences of “North” in the selected field and replace with “Nth”. Depending on the Find and Replace option selected, records which only contain the text “North” may be replaced or all records which contain the text “North” along with other text may be replaced.

The search result is held in a temporary table which is named according to the search text specified. In the above example, a temporary table called “Riversleigh” is created.

Selecting Table Records

• Select by Group

Additional tools are provided for selecting map objects in a map window (see Selecting Objects)

Select by Group

Discover>Data Utilities>Select by Group

Use the Select by Group tool to select all records with specific values or attributes from a specified column in a table.


Select by Group dialog

Use this option to quickly see a list of all the unique entries in a selected column. For example, visualize a list could easily be created of all the rock types logged in a drillhole downhole lithology table. The user could then choose just the units of interest (e.g. QV and Fault) and create a query of all intercepts with these lithologies.

To use the tool, choose the source table from the Table to Select From pull-down list. Select the attribute column from the Selected based on field pull-down list. A complete list of unique data entries for the selected column is displayed in the Groups window.


• Browse selection displays the selected records in a browser window.

• Map Selection displays the selected records in a new map window.

• Zoom map to selection will zoom to the extents of the selected records in the current map window.

The output query can be given a unique name by entering a value into the Selection Result Table text box.

Press OK to complete the query.

Sorting Tables

Discover>Table Utilities>Sort a Table

The Discover>Table Utilities>Sort a Table command enables a user to sort an original table permanently based on either a primary column or a primary and secondary column, in the one step.

In the Table Sort dialog select the table to sort from the Table Name list. Select the primary column to sort the table from the Primary Column Name drop-down list. Select the Ascending or Descending option to sort the records in ascending or descending order. If required, a secondary sort column may be selected from the Secondary Column Name drop-down list. Click OK to sort the table.

The unique field attributes will initially populate the Unselected pane. Move the required attributes to the Selected pane using the selection buttons. To select consecutive attributes hold the left-mouse button and drag or use the SHIFT key in combination with the mouse control. To select non-consecutive attributes use the CTRL key in combination with the mouse control.

A number of options are provided for displaying the output query:

Note For Alpha-numeric character columns, these will be sorted as a character. Ie. “A11” is greater than “A100”, but “A011” is less than “A100”.


Sort Table dialog

By default, the selected table is sorted by the first column, with no secondary sort column.

A new table can be created which will make a copy of the original table before sorting. This will have a default name of the input table with “_Sorted” suffixed...

Note This operation cannot be undone. If you wish to add a row number prior to sorting, so that the original table order can be retrieved by sorting on this column, you can use Discover>Table Utilities>Add Unique Identifier.


Changing the Map Bounds of a Mappable Table

Discover>Table Utilities>Alter Map Bounds

The Alter Map Bounds function enables a user to adjust the map bounds of a mappable table. The map bounds of a mappable table may need to be modified under the following circumstances:

New map objects are to be added that are located beyond the bounds of the existing non-earth map table.

Map objects digitized from a raster layer and then saved may have restricted map bounds that prevent the addition of new map objects into the layer

Loss of data precision resulting from map bound extents that are set too large for a non-earth map table. Restricting the bounds can help to improve the data precision.

Alter Map Bounds dialog

Select Discover>Table Utilities>Alter Map Bounds and choose the table to modify the map bounds. In the Alter Map Bounds dialog the Table Name, CoordSys, Current Map Bounds and the Current Data Limits for the selected table are displayed. The New Map Bounds Minimum and Maximum X and Y coordinates are automatically populated with the values calculated for the Current Data Limits. The Current Data Limits encompass all of the map objects currently in the table.


If the Current Data Limits are not acceptable, enter new map bound coordinates into the Minimum and Maximum X and Y windows. Click OK to alter the map bounds.

Splitting Tables

Discover>Data Utilities>Table Split

The Split Table utility allows a table to be split into multiple tables using unique attribute values in a field. For example, create separate tables for different geological units covering a project area from a master table, extract tenement data by holder or split out open file geochemical data by company.

Note When using this option, data outside the specified boundary is deleted from the table file and cannot be recovered.


Table Split dialog

Select the source table from the Table to Split pull-down list. Select the attribute field (e.g. company_name or lithology) from the Split based on field pull-down list. The number of unique entries or groups in the selected field will be indicated. If there are spelling mistakes or different entries for the same attribute in a field these will be treated as unique and separate tables will be created for each.

A table can be split by two methods;

• Auto – A new table will be automatically created for every unique attribute in the selected field.


• Custom – The user can individually select which attributes are to be split or combine individual attributes into Groups for splitting. A combination of individual and grouped attributes can also be chosen. Multiple attributes grouped together will form a single output table.

To Group a series of attributes (into a single output table), first deselect all the attributes (None). Then in the Unselected list, hold the left-mouse button and drag or use the SHIFT key in conjunction with the mouse control. To select non-consecutive attributes use the CTRL key in conjunction with the mouse control.

When the attributes have been selected for grouping, press the Select button to create the split group. The Group Properties dialog will open listing the Group members. The Group Name can be modified if required.

Table Split Group Properties dialog

In Custom mode, the unique field attributes will initially populate the Selected pane. To select and deselect items use the selection buttons.

To split a table using a limited number of individual attributes, press None to deselect all attributes, then migrate each required attribute separately to the Selected pane using the Select button. This process must be repeated for each required attribute. If most (but not all) of the unique attributes in the source table are required in separate tables, change from Auto to Custom mode, and just deselect the unrequired attributes from the Selected list.


Digitizing and Data Entry

Discover>Data Utilities>DigData

Use the Discover DigData utility to streamline the entry of attribute data for digitized map objects. Attribute data in a column can be incremented automatically, populated with a constant value including X and Y coordinates or selected from a look-up table. Attribute data can also be entered manually for selected columns after each map objected is digitized. If the digitized map object style is selected from the styles library (see Using Object Styles), the style attribute can also be automatically added to each new digitized object.

When digitizing point data such as sample sites from a field plan it is useful to be able to add attribute data to one or more columns as each point is digitized. Within MapInfo attribute data must be entered into the Browser window or via the Info tool once the map objects have been created. If attribute data entry has been setup in DigData then aside from columns automatically being populated with the pre-set attributes a dialog is displayed which allows users to manually enter attribute data for each digitized map object.

When the DigData menu option is selected a separate DigData menu is added to the MapInfo menu bar. Select the DigData>Data Table menu option and choose a table for data entry. The Data entry to columns dialog is displayed:

The default output table name for the newly created tables uses the original table name with the unique attribute or group name extension. To change the default output name, click on the Save button. The {GROUP} placeholder must be part of the output table name. As MapInfo truncates table names longer than 30 characters when they are displayed in MapInfo it is recommended to try and keep output table names as short as possible.


Highlight the columns from the table to populate with attribute data during the digitizing process. A maximum of 10 columns can be used for data entry with DigData.

DigData also allows X and Y coordinates to be automatically added to the table as each map object is digitized. Check the Easting and Northing boxes and select the X and Y columns from the pull-down lists. This feature is useful when digitizing point data. If the digitized map object is not a point then the X and Y coordinates of the object centroid are added to the table.

Note DigData can be used when digitizing any type of map object (not just points) and works in the same way when digitizing from the screen or via a digitizing table.


Setting Increments and Constant Values

Discover>Data Utilities>DigData>Set Up Increments

Digitizing increments using DigData

DigData attribute data may be assigned using the following methods:

• Increment

Check the Increment box to automatically add a consecutive value to each new digitized map object. Increments are useful for populating sample number columns and can serve as the primary identification field for an object.

Increment columns do not have to be numeric but must contain one or more numeric parts. Sample numbers commonly begin with an alpha prefix and some naming conventions include an additional alpha string in the middle of the sampleID. For Example, SS11235 or SS87RC-69435). DigData will perform the increment on the last number in the string which, in the example above, would be SS87RC-69436.

• Value

To assign a constant value to an attribute column check the Value box and enter the required value into the window to the right of the checkbox. The constant value will be entered into the selected column until the value is changed manually. Constant values are useful for attributes such as Line number, Sample type, Rock Unit, etc where many records have the same attribute.


• Use Style

If the Use Style box is checked for an attribute column an empty window in a pop-up data entry dialog will be displayed enabling a user to manually enter individual values after each map object is digitized. If a style is selected from the styles library (see Using Object Styles), the style name will automatically be added as the value.

• Use Look-Up

If the number of attribute values is relatively standard it may be best to create a look-up table and check the Use Look-Up box next to the attribute column. The look-up table must be already open and selected from the pull-down list to the left of the Use Look-Up option. In the pop-up data entry dialog a pull-down list of values will be available in order to choose the required attribute.

Manual Data Entry

To enter manual attribute data for each map object as it is digitized or view incremental or constant values select the DigData>EnterData menu option. A tick will be displayed next to the EnterData option in the DigData menu to show the option is toggled on. To turn off the EnterData mode check, select the menu option again.

Once a map object is digitized the data entry dialog box will be automatically displayed for all the attribute columns selected. Any increment or constant value fields should be automatically populated. Other fields will have the last values selected and can be modified as required. Enter the required attribute data, click OK on the dialog and digitize the next object.


Automated Data Entry

If the attribute columns are to populated with only increment or constant values turn off the check next to the DigData>EnterData menu option. The constant and increment values will be automatically written to each new record as the map object is digitized.

At any time while DigData is being implemented the attribute data columns can be re-specified. New increment intervals or starting numbers can be selected and constant values can be modified via the Set Up Increments menu option. To add new columns populated with attribute data requires the table to be selected again in the Data Table menu option.

Select the Beep On menu option to activate a beep sound every time a map object is digitized. Re-select the Beep On menu option to turn off the beep.

The EnterData and AutoData options can be combined when digitizing. Check EnterData and enter new values for the next digitized record, then return to AutoData, where fields are incremented from the previous record values. This enables any changes made to the last record with the Info tool or in the Browser window to be utilised by DigData.


Adding Unique Identifiers to Table Records

Discover>Table Utilities>Add Unique Identifier

Unique Identifier tool

The Discover Add Unique Identifier (UID) utility allows an incrementing numeric code, with optional alphabetic prefixes/suffixes, to be quickly assigned to a table based on the row number.

This can be used to generate a unique ‘sample code’ for table if this does not exist, or is in an invalid format for sorting. To create add a unique ID to each row in a table:

1. With the tool open, select the Input Table.


2. Enter a Start Number and Increment Value (e.g. 434, 435, 436, etc).

3. Optionally specify a Prefix and/or Suffix (e.g. pictured example adds a 'GHRC' hole refix to the numeric value): the resulting code will therefore be an alphanumeric code.

4. Either add a New Field (and specify its position) or use an Existing Field for the output UID. For new fields, the field type will automatically be assigned depending on the UID format. For existing fields, only field types compatible with the UID formatting defined will be able to be selected.

5. Press OK to populate the table.

Updating Multiple Columns

Discover>Table Utilities>Multiple Column Update

The Multiple Column Update tool enables columns in one table to be updated with data from columns in another table where there is a common join such as sample number or drillhole name between the two tables. Discover can update up to 30 columns at the one time so long as the columns already exist in the table to update. Only the records which match the join criteria are upated and any other unmatched records in the table retain their original values. This enables subsets of data to be easily updated.

For example:

• Update surface sample table with assay data

• Update drillhole collars with survey data


Multiple Column Update dialog

To update multiple columns:

1. Open the table to update into MapInfo.

2. Make sure that the table to update contains columns to store the new values. If the columns do not already exist in the table create them using Table>Maintenance>Table Structure or the Discover Multi-table, Multi-field Editing.

3. Open the table to update the values from into MapInfo.

4. Select Table Utilities>Multiple Column Update.

5. Select the table to Update values in from the pull-down list.


6. Select the table to Get values from in the pull-down list.

7. Select the column in the table to update pull-down list and select the matching join column in the from value table pull-down list.

8. Under Field Mapping select the first column in the Update From pull-down list.

9. Select the corresponding column in the table to update from the Update To pull-down list.

10. Repeat steps 8 and 9 to match all columns to update from and to in each table.

11. Click OK to update columns.

Additional options:

Troubleshooting:

• To reduce processing time make sure table to update from is in native MapInfo format instead of linked to an Excel or Text file.

• To reduce processing time index the the join column in each table. To index a column see Table>Maintenance>Table Structure.

Note If the column name in Update To matches the column name in Update From simply select the next Update From column to automatically display the matching Update From column.

To save or load a set of Field Mappings, use the save/load buttons. This will save/load the mappings based on the field names but not types. If not all saved fields exist when loading a mapping, a summary report will be provided detailing which fields do not exist or are invalid.

To remove an entry under Field Mapping, select a cell in the row and click the Delete button.

Check the Allow Undo option to enable updates to a table to be undone using File>Revert Table. This will return the data in the table to the last time it was saved.

If a table is in non-native format, the join fields are not indexed or the datatypes are different between the update from and to columns the Alert button is displayed. Place the cursor over the button to view message. See Troubleshooting for more information.


• To avoid data loss, ensure columns in the table to update are the same datatype as the columns in the update table. Eg. Character, Float, Date, etc. To compare and modify tables use the Discover Multi-table, Multi-field Editing or Table>Maintenance>Table Structure.

Working with Multiple Tables

• Packing Multiple Tables

• Appending Multiple Tables

• Importing Multiple MID/MIF Files

• Exporting Multiple MID/MIF Files

• Reprojecting Multiple Tables

• Multi-table, Multi-field Editing

Packing Multiple Tables

Discover>Table Utilities> Multi-Pack

Use Discover>Table Utilities>Multi-Pack to pack multiple tables. Select the tables to pack from the available open tables list. Choose to pack only the tabular component of the table, the graphical component of the table or both tabular and graphical table components. Click OK to pack the selected tables.

Multiple table selection for packing tables


Appending Multiple Tables

Discover>Table Utilities>Multi-Append

Append multiple tables to another table. Select the table to append to from the available Open Tables list. Select the table to append the other tables to from the Append to Table pull-down list. Choose the order in which the tables are to be appended. Use the arrow keys to re-order if necessary. Click OK to append the selected tables.

Importing Multiple MID/MIF Files

Discover>Table Utilities>Multi-MIF Import

Import multiple MID and MIF files into MapInfo.

The user is prompted to select a directory to store the new MapInfo files created from the imported MID/MIF files. Follow the same procedures for Multi-Open menu option regarding selecting folders and files to add to the Selected Files window, choosing the Preferred View and removing files from the list.

Note With the Multi-Append option, all tables selected must have the same number of columns. If the tables have the same number of columns but do not have the same structure then data conversion errors (such as when character values are read into a numeric column) may occur during the appending process.


Exporting Multiple MID/MIF Files

Discover>Table Utilities> Multi-MIF Export

Export multiple tables to MID/MIF format. Select the tables to export from the available open tables list. Choose to export to the same directory as the tables or to a new directory. Click OK to export the selected tables.

Reprojecting Multiple Tables

See Reprojecting Multiple Tables under Coordinates and Projections.

Multi-table, Multi-field Editing

Discover>Table Utilities> Multi-Table Structure Manager

The Multi-Table Structure Manager is a powerful tool allowing the easy comparison and editing of multiple fields across multiple tables. It essentially provides multi-table and field functionality of the MapInfo Modify Table Structure dialog (Table>Maintenance>Table Structure). It is of particular use when trying to alter the structure (field names, formats, field order, etc) of a number of similar data tables prior to combining them using the Table Utilities>Multi-Append tool.

The Multi-Table Structure Manager contains the following multi-field editing options:

• Addition


• Deletion

• Copying

• Rename

• Type Alteration

• Reorder

The Multi-Table Structure Manager dialog matching 2 tables by field name

Field Display

The Table Structure Manager dialog enables multi-table comparison through a customizable grid/browser view. First, a Base Table needs to be selected from the pull-down list of open tables. Generally this is the table whose structure will be used as a template for other comparison tables; it will be the first table displayed. Multiple comparison tables can then be selected; these will be displayed adjacent to the Base Table.

Two field display options are available at the top right of the dialog:

The tables to be compared/altered need to open in MapInfo prior to running the tool. The Multi-Table Structure Manager can be accessed either via the menu option on the Discover>Table Utilities menu or by the shortcut button on the Discover toolbar. Image and grid tables cannot be viewed or modified with this tool.


• Match by Field Name will display fields with the same name in the same row. This is an excellent way to check whether assay fields are named identically e.g. two tables might have a “Cu” field, whilst a third table might have a “copper” field. Another example: one table may have a “HoleID” field, whilst another a “Hole_ID” field. It also allows a simple visual comparison of the field types of matching fields: three tables may have “HoleID” fields of differing types (e.g. Character(10), Character(40) and Integer).

• Non-matching fields are displayed in a cascading view below the Base Table fields. This tool will attempt to match field names between comparison tables in the cascade view.

• The Case Sensitive option at the bottom left of the dialog enables matches only between field names of the same case (e.g. “HoleID” will not match “holeID” or “holeid”).

• Match by Column Order: fields are displayed in their individual table orders. This is useful once field names and field types have been mirrored/replicated across the tables (using the Match by Field Name option): it allows an easy visual comparison of whether the fields are ordered identically across multiple tables.

The Table Structure Manager dialog is resizable, as are individual column widths.

Field Editing

At the base of the Table Structure Manager dialog are the editing tools. These require a field selection to open: this can be a single field, multiple fields within a table or multiple fields across multiple tables. Field selection is with the left mouse button: either hold this button down to highlight multiple adjacent fields, or use it in combination with the keyboard CTRL button to select non-adjacent cells. However, not all editing functions can handle multiple cell selections (e.g. you cannot rename multiple fields in the same table at once); an appropriate warning message will be returned if the current selection is invalid for the selected editing tool.

Each editing button will open an appropriate dialog, which can be resized to allow the full target file name to be visible:


The Add Fields dialog resized to display the full target field names

• Add - adds a new field with the specified name and type to each selected table. The new field will be added to the end of each table. This option requires a single field selection in each target table; this can be a populated or blank field, neither of which will be altered.

• Delete - deletes all selected fields.

• Copy – copies the selected fields to other tables. The field, if it does not exist, will be appended to the end of the destination table.

The warning dialog displayed when copying a field that already exists

• The Edit button accesses the following functionality:

• Rename - a single field from each table can be renamed.


• Change Types - multiple fields can have their types/format altered (e.g. from integer to float). The selected fields do not need to have the same initial type. Note however that this may result in data truncation or loss, e.g. changing latitude and longitude fields from float to integer will result in a massive loss of precision. A warning message to this effect will be displayed prior to finalising field type alterations.

The warning dialog displayed when altering field types

• Order - a single field from each table can be assigned a new field position. This will result in a reordering of all fields below this new position, e.g. moving a field to the 3rd position within its table, the existing 3rd field will be moved to the 4th position, the 4th to the 5th, etc. If the specified position does not exist within the table, the field will be placed at the end of the table (e.g. moving a field in a 10 field table to position 20 will simply place it at the end of the table).

The Display Object Columns option at the bottom left of the dialog will add an Obj field to each mappable table. This field is not editable, but allows a count of the total number of objects in a table, as well as a count of each object type (points, lines and/or regions). To initiate an object count, select the pull-down arrow in the Type cell of the appropriate Obj field; for a small number of objects the total and sub-counts will be displayed.

An Object field displayed with its record count

If the table contains a large number of objects, a warning message will be displayed indicating the total object count and that the sub-count may take some time.


Object count warning message for larger datasets

Press OK to continue with the count. When the warning message disappears, re-access the Type pull-down arrow to view the count result.

A Text Report of the current multiple table comparison (it requires at least two tables to be open in the dialog) can be generated using the button at the bottom left of the dialog. This output can be copied and pasted to a text editor (e.g. Notepad or Word) using CTRL+C and CTRL+V.

5 Data Processing and Statistics 137

5 Data Processing and Statistics• Pre-processing and Cleaning Data

• Classifying Data

• Normalizing or Levelling Data

• Computing Summary Statistics

• Computing a Correlation Matrix

Pre-processing and Cleaning Data

Geochemical data is often received in a format that requires some manual manipulation before the data can be used in geochemical analysis. Use the Data Handling tool to pre-process and clean the input data.

The Data Handling Options tool is available from utilities on the Geochem menu and selected other tools. The processing options available include:

Negative values

• Set negative values to Null, which is statistically ignored, or any user-specified value. For example, if –999 is used to identify “below detection limit,” you can reset these values to zero or a discrete value such as 5 ppb.

• Multiply negative values by a constant—for example, multiply by –0.5 to convert each negative value to half the detection limit.

Non-numeric values

• Set non-numeric values to Null or any user-specified value.

Zero values

• Set zero values to Null or any user-specified value.

Replacement values

• To apply different replacement values for element data in a table or for multiple replacements within the same element field, create a custom template. The template contains the element name, the original assay value, and the replacement assay value.


To pre-process a geochemical data table:

1. Open a geochemistry table in a map window.

2. On the Geochem menu, click one of the menu options; for example, Point Classification.

3. Select the geochemistry table. For more information about selecting a table, see the relevant topic in Geochem Menu)

4. Click the Data Handling Options button.

5. Under Input, select the options you want to apply to negative, non-numeric, zero, and other data values. For more information about the options available, see Data Handling Options.

6. Under Output, select the options you want to apply to the output table. For more information about the options available, see Data Handling Options.

7. Click OK and return to the previous dialog and continue processing the modified table.

See also...Data Handling Options...Geochem Menu

Classifying Data

Point Classification of data is used to segregate a dataset into groups defined by a range or group of values. Point symbols can be modulated by colour, size and/or symbol type using one or more data fields.

• Classifying Data by Colour, Size, and Symbol

• Multi-field Classification

• Trivariate Point Classification

Classifying Data by Colour, Size, and Symbol

Geochemical data is often collated from different sources and to highlight this graphically a different symbol type can be assigned to each sub-grouping of the dataset. Assay values can then be classified into value range groups via various statistical methods and displayed as the colour or size of the symbol.


Point classifications can be displayed as a thematic map overlay or the new point symbols can be saved to the existing table or new table.

To apply a classification scheme:


2. On the Geochem menu, click Point Classification.

3. In the Point Classification dialog box, in the Select table box, click the geochemistry table.

4. In the Select column box, click the field you want to classify.

5. To ignore or replace negative, zero or non-numeric values in the data field click the Data Handling Options button. For more information, see Pre-processing and Cleaning Data.

6. Select a classification. You can classify data by colour, size and symbol concurrently.

The classification divisions and number of values in each are displayed in tthe classification table. For many datasets, a linear range classification will not be suitable to show the data range variation. There are a number of statistical methods to classify data, such as log and exponential distributions, and percentile groups.

• To classify by colour, on the colour tab, select the Classify by colour check box, and then select a method for distributing the data values for each colour division in the Colour method box. To change the colour scheme, in the Colour table box, select a colour lookup table.

• To classify by symbol size, on the size tab, select the Classify by size check box, and then select a method for distributing the data values for each size division in the Size method box. To change the size range, edit the values in the Size min, Size max, and Size step boxes.

• To classify by symbol type, on the symbol tab, select the Classify by symbol check box, and then select a method for distributing the data values for each symbol division in the Symbol method box. To change the symbol range, edit the values in the First char, Last char, and Char Step boxes.


7. To edit the colour, size, or symbol assigned to a division, in the classification table, click the Colour, Size, or Symbol cell and type or select another value.

8. To edit a division, click in a Description, >= or < cell and type a new value.

10. Choose output options:

• Click Create new table to create a new table containing the classification applied. Click New table options to select which fields in the input table will be added to the output table and to change the name of the new table.

• Select the Null symbol check box to apply the Base symbol to all null value data. Only selected classification properties (colour, size, symbol) are applied to null value data.

• Click Change source to apply the classification in place to the input table.

• Click Thematic map to display the classification as a thematic map. Any Null or unclassified points will be displayed with the Base symbol. Points styles can be further modified with the Map>Modify Thematic Map option or by double-clicking on the Theme Legend window.

11. When you have completed defining the classifications (on the colour, size, and symbol tabs) for the selected data field, click Apply.

To add or remove divisions in the classification method, use the Add, Remove or Clear All division buttons. Note that divisions cannot be changed for unique value groups, such as for non-numeric data, except for a custom classification method.

9. Save a classification or load a saved classification using the Save and Load buttons. This saves all colour, size and symbol classifications.

Note Values outside the lowest and highest classification groups will be ignored. However, the tool applies continuous internal data ranges. Any gaps from one classification group to the next will be ignored.


To save or restore a classified table:

• On the MapInfo File menu, click Save Table to save the classification, or Revert Table to restore the table to its last saved state. To save an RGB classification thematic map, you must save the workspace.

See also...Multi-field Classification...Trivariate Point Classification...Geochem Menu

Multi-field Classification

To modulate the point styles by two or three different fields, apply the classifications consecutively, saving the classified table between each classification. For example, to modulate the point colour by Cu, and the point size by Pb:


2. Select the table, and then in the Select column box, select the Cu field.

3. On the colour tab, select the Classify by colour check box, and then select the classification options.

4. Under Output type, click Change source, and then click Apply.

5. On the File menu, click Save Table.


7. Select the table, and then in the Select column box, select the Pb field

8. On the size tab, select the Classify by size check box, and then select the classification options.

9. Under Output type, click Change source, and then click Apply.

10. On the File menu, click Save Table.

Note The classified symbol may be hidden by a coincident point symbol. Use the Discover>Map Window >Select by Graphical Styles option to query the map table for all the samples that fall within a particular Point Classification for a combination of colour, size, symbol style properties.


See also...Classifying Data by Colour, Size, and Symbol... Trivariate Point Classification

Trivariate Point Classification

Trivariate Point classification of geochemical data is used to identify homogeneous groups of data within a sample population which can be distinguished from other groups. Samples that pass a combination of the thresholds for three selected elements are displayed using the same symbol style, colour and size to enable them to be easily viewed in the map window. Each element is assigned an RGB channel (red-green-blue) and a threshold value; during processing each sample is compared with the threshold values set for its channel.

Trivariate classification can be used to highlight points that are above a threshold in individual RGB channels, as well as above combinations of thresholds on multiple RGB channels.

The output classifications can be displayed as a thematic map overlay or the new point symbols can be saved to the existing table or new table. Classification legends can be displayed as a thematic legend or as a MapInfo table which can be edited and scaled. Each sample is assigned a point classification code which is saved to a new column in the original or new table.

The classification code is a three-digit binary number (stored as a character string) that indicates if the value passes the threshold on each channel. For example, the code 101 indicates that the threholds on the R and B channels have been passed (1) but has failed (0) on the G channel.

To apply a trivariate classification scheme:


2. On the Geochem menu, click Trivariate Point Classification.

3. In the Trivariate Point Classification dialog box, under Table, in the Select table to classify box, click the geochemistry table.

4. To ignore or replace negative, zero or non-numeric values in the input fields, click the Data Handling Options button. For more information, see Pre-processing and Cleaning Data.

5. Under Channel selection, in the Red box, click the field you want to assign to the red channel. Make field selections in the Green and Blue boxes.


6. Click a threshold type:

• Value: Type a threshold value for each channel in the adjacent boxes. The data range is displayed to the right of the box.

• Percent: Type or select a percentage threshold for each channel in the adjacent boxes. The corresponding threshold value for each channel is displayed to the right of the box.

• Percentile: Type or select a percentile threshold for each channel in the adjacent boxes. The corresponding threshold value for each channel is displayed to the right of the box.

7. For each channel, type or select a threshold value in the corresponding box. Or click the Use single threshold check box to use the same threshold (defined for the red channel) on all three channels.

8. Select output options:

• Save classification code to field: The classification code field name. Click the box to select a different, existing character field, or type a new field name. The default field name is _ClassField.

• Set Point Styles: Click to assign point styles to each of the eight RGB classification codes. For more information, see Setting Point Styles.

• Display custom legend: Select the check box to display the classification as a thematic legend. For more inforamtion, see Displaying a Point Style Legend.

• Display MapInfo legend: Select the check box to display the classification as a MapInfo table. For more inforamtion, see Displaying a Point Style Legend.

• Display/classify points that incorporate null values: Select the check box to classify and display all points in the input table. Clear the check box to exclude those with null values.

9. Select the type of output:

• Thematic map: Display each sample point according to their assay values relative to the specified threshold level as a thematic map. The sample point style, colour and size are as defined by the Set Point Styles option.


After the thematic map is created, points styles can be modified through the Map>Modify Thematic Map option or by double-clicking on the Theme Legend Window. To save an RGB classification thematic map, the workspace must be saved.

• Change source: Permanently colour each sample point in the base geochemistry table according to their assay values relative to the specified threshold level. The sample point style, colour and size are as defined by the Set Point Styles option.

• Create new table: Create a new table with each sample point coloured according to their assay values relative to the specified threshold level. Click the New Table Options button and select fields from the input geochemistry table to add to the new classification table.

By default, the new table is named by adding the “_Classified” extension to the input table name. The new table is saved to the same directory as the base geochemistry table. The new classification table is automatically displayed in a new map window.

10. Click OK to apply.

Setting Point Styles

For each of the possible eight classification codes, a separate point style can be set. Each sample will be coloured in the map window according to these classification point styles. To view or modify the default point styles click the Set Point Styles button. The Point Style Setup dialog contains a symbol button for each classification code.

Assigns a 12pt yellow solid-filled circle to the 110 classification code.

Note It is not possible to control the order in which multiple sample points at the same location are displayed. Therefore it may appear that a sample which is coloured is masked by overlying sample points. Use the Discover>Data Utilities>Select by Group option or an SQL query on the “_Classfield” column to query the table for all the samples that fall within a particular RGB Classification.


To change a symbol style, click the symbol button and choose a new symbol style, colour or size for the selected code. The Null symbol shape will be applied to all points assigned a null value by the Data Handling Options tool. To use the same symbol for all RGB threshold combinations, check the Use single symbol style box, and select the symbol style to use. To automatically size the symbols across the classification codes, select the Graduate symbol size from check box and type a size for the smallest symbol.

Displaying a Point Style Legend

Two legend options are available for identifying what each symbol style represents.

Custom Legend

To create a legend table that can be edited and scaled as a permanent MapInfo table, select the Display custom legend check box. The custom legend displays the legend items as text or point objects, which can be modified using the standard MapInfo map object style options. The legend window is created in a non-earth centimetre projection and can be placed in a layout and scaled using the frame tool.

The first five characters of the red, green and blue channel field names will be displayed in place of the channel names. The threshold value and the threshold value as a percentage of the maximum value is also displayed in the legend table.

MapInfo Legend

Check the Display MapInfo legend box to create a MapInfo legend similar to those created in the MapInfo Create Legend or Create Thematic Map menu options. MapInfo legends cannot be scaled and must be saved as part of a workspace. To modify a MapInfo legend, double-click in the legend window and use the Styles and Legend buttons in the Modify Thematic Map dialog.

Null Values

If the Display/classify points that incorporate null values option is checked, then a sample with a null or 0 value (one or more elements) is deemed to be below the threshold and will be displayed using the corresponding point symbol. If samples that contain only valid data values for all of the selected elements are to be included in the final point classification display, then clear this option.

To ignore or replace negative, zero or non-numeric values in the data table click the Data Handling Options button. See Pre-processing and Cleaning Data in for more information on using this tool.


Normalizing or Levelling Data

Many statistical processes require data to be normally distributed. Because geochemical data is often log-normally distributed or positively skewed, it must first be transformed or “levelled” so the data conforms to a normal distribution. The Discover levelling utility provides a number of standard levelling operations that can be applied in normalize the data.

Often a dataset contains mixed sample populations such as soil samples taken over different rock or regolith lithologies, stream sediment samples taken from different mesh size fractions or samples analysed by different analytical techniques. In these cases data should be levelled according to each distinct value for a group.

Data levelling can be applied to either an entire dataset table or a subset (Query).

To level (normalise) a data set:


2. On the Geochem menu, click Data Levelling.

3. In the Levelling Utility dialog box, in the Select table to classify box, click the geochemistry table.

4. To ignore or replace negative, zero or non-numeric values in the input fields, click the Data Handling Options button. For more information, see Pre-processing and Cleaning Data.

5. In the Fields to level box, select the assay fields to level. To select multiple fields, click the first field and drag to select consecutive fields, or hold the CTRL key to select non-consecutive fields.

6. In the Fields to level by box, select the fields that contain data such as sample geology or regolith type, sample type or analytical method which will be used in the levelling process to calculate values for each unique attribute entry in these fields. As each field is selected the number of distinct values in the column is automatically displayed. To select multiple fields, click the first field and drag to select consecutive fields, or hold the CTRL key to select non-consecutive fields.

7. In the Levelling operations box, select one or more operations. For more information, see Levelling Operations. To select multiple operations, click the first and drag to select consecutive operations, or hold the CTRL key to select non-consecutive operations.


8. To filter the results columns by a minimum value, select the Include summary columns check box and type a value in the Threshold box. The raw assay values will also be output.

9. To change the output table name and folder, in the Output table box, edit the default name or type a folder and file name.

10. Click OK to apply.

The levelled data table is created and opened into a new browser window.

Levelling Operations

Select one or more of the following levelling operations to perform on the geochemical data:

• Mean: Divide each variable by the mean of the group it belongs to. This method performs a linear transform of the data to give a response ratio or times background measure. Suitable for normally distributed data.

• Log-mean: Log transforms each variable and divides by the mean of the group it belongs to. This method performs a linear transform of the data to give a response ratio or times background measure in log space. Suitable for log-normally distributed data.

• Z-score: Converts each variable to a Z-score for the group it belongs to. This method performs a linear transform of the data into units of standard deviation centred around zero (the mean value). Suitable for normally distributed data.

Note Levelled data values are calculated for each element and each selected category. Use the Discover>Data Utilities>Select by Group menu option to check unique field values and remove any duplicate or misspelled entries and populate blank entries prior to running the Data Levelling utility.

Note To see the source data fields after any data handling options have been applied, in addition to the new levelled fields, select the Include working columns in output table option in Data Handling Options. These fields are the data values used to calculate the levelling operations. If all negative values in a field are converted to zero, they are displayed as zero. Null values will also be displayed as zero, but will be handled correctly internally (separately to true zeros).


• Log(Z)-score: Log transforms each variable and converts to a Z-score for the group it belongs to. This method performs a linear transformation of the data into units of standard deviation centred around zero (the mean value). Suitable for log-normally distributed data.

• Median: Divides each variable by the median of the group it belongs to. This method performs a linear transform on the data to give a response ratio or times background measure. It is very similar to the mean method but is more robust to outliers or extreme data values. Suitable for most distributions.

• Median-MAD: Subtracts the median from each variable and divides by the median absolute deviation (MAD) from the median for each group. This method performs a linear transform which gives a ratio or times background measure. More robust than the median method to outliers or extreme data values. Suitable for most distributions.

• Rank-percentile: Ranks each variable within the group it belongs to and then converts it to the equivalent percentile value. This method performs a non-linear transform that is suitable for most distributions.

• Rank-Gauss: Transforms variables in each category using a non-linear scaling method so the distribution approximates a normal distribution. The results are then rank ordered. This method performs a non-linear transform that is suitable for most distributions.

• Standard deviation: Divide assay value for each element by the background standard deviation concentration calculated for each attribute group.

• Variance: Divide assay value for each element by the background variance concentration calculated for each attribute group.

• Log: Apply base 10 logarithm to each assay value.


Correlation Statistics dialog

A Correlation Matrix can be calculated for either an entire dataset table or a subset (Query). Choose Compute Correlation Matrix from the Geochem menu and select the input from the Select table pull-down list. Select the assay fields to be used in the correlation from the Select Fields window. Click on an assay field and drag holding the left mouse button to select consecutive fields. Use the Ctrl key to select non-consecutive assay fields.

The correlation matrix can also be calculated based on attribute entries from another field in the geochemical table such as geology. Select the field to use from the Select Group Field pull-down list.

To ignore or replace negative, zero or non-numeric values in the data table click the Data Handling Options button. See Data Handling Options in this section for more information on using this dialog.

The default Output Table is named using the original geochemical base table with a “_CorMatrix” extension and saved to the same directory. Enter an alternative name and location if desired. Click OK. The correlation matrix data table is created and opened into a new browser window. If a group field is selected a separate correlation table is created for each distinct value. The distinct value is included in the output table name.


Computing Summary Statistics

The Summary Statistics utility reports a number of common statistical measurements for a geochemical dataset. If a dataset contains mixed sample populations such as soil samples taken over different rock or regolith lithologies, stream sediment samples taken from different mesh size fractions or samples analysed by different analytical techniques then statistics can be calculated for each distinct value in a group.

As geochemical data generally has a lognormal or positively skewed distribution a number of additional mean calculations aside from the arithmetic mean have been included such as geometric and harmonic.

Summary Statistics Dialog

Summary Statistics can be applied to either an entire dataset table or a subset (Query or Selection). Choose Summary Statistics from the Geochem menu and select the input from the Select table pull-down list. Select the assay fields to be used in the statistics calculation from the Select Fields window. Click on an assay field and drag holding the left mouse button to select consecutive fields. Use the Ctrl key to select non-consecutive assay fields.


Statistics can also be calculated based on attribute entries from another field in the geochemical table such as geology. The results table will contain an entry for each unique geological unit along with statistics calculated from the samples that are located within each unit. Select the field to use from the Select Group Field pull-down list.

To ignore or replace negative, zero or non-numeric values in the data table click the Data Handling Options button. See Data Handling Options in this section for more information on using this dialog.

Statistical Operations

Select one or more of the following statistical operations to calculate for the geochemical data:

• Count – Total number of samples in dataset

• Count Valid – Number of samples used in the statistical calculation

• Count Invalid – Number of samples not used in the statistical calculation. Any samples set to null in the Pre-processing and Cleaning Data options are invalid samples.

• Min - Minimum assay value

• Max - Maximum assay value

• Sum - Sum of assay values

• Mean - Sum of assay values divided by number of samples

• Median - Middle assay value or 50th percentile of ordered assay values. Median of even number of samples calculated using mean of two middle assay values.

• Range - Maximum assay value minus minimum assay value

• Mode - Assay value that occurs most frequently

• RMS (Root Mean Square) - Square root of the mean of the squares of each assay value.

• Sum of Squares - Sum of the square of each assay value

• Geometric Mean - Used for positively skewed distributions. Nth root of the product of the assay values.


• Harmonic Mean - Sum of the reciprocals of each assay value divided by the number of samples.

• Trimmed Mean - Remove a percentage of the largest and smallest assay values and re-calculate arithmetic mean on trimmed dataset.

• Median Dev. Mean – Median deviation from the Mean

• Median Dev. Median – Median deviation from the Median

• Variance - Measure of the ‘spread’ within a dataset. Average squared deviation of set of assay values from their mean.

• Standard Deviation - Measure of the ‘spread’ within a dataset. Square root of the variance.

• Skewness - Estimate of asymmetry of a distribution compared with a normal distribution.

• Kurtosis - Degree of ‘peakness’ or ‘flatness’ of a distribution compared with a normal distribution.

• InterQuartile Range - Measure of the ‘spread’ within a dataset. Difference between the 75th (3rd) and 25th (1st) quartiles.

• Percentile - Division of a dataset into one hundred groups containing equal numbers of samples. Each percentile represents the proportion of samples that lie below this value; e.g. 60% of data lies below the 60th percentile, 95% of data lies below the 95th percentile, etc.

• Count = 0 - Number of samples with zero assay value

• Count < 0 - Number of samples with assay values less than zero

• Count of Minimum - Number of samples with minimum assay value

• Percent of Minimum - Percentage of samples with minimum assay value

• Percent = Null – Percentage of invalid samples

The default Output Table is named using the original geochemical base table with a “_Stats” extension and saved to the same directory. Enter an alternative name and location if desired. Click OK. The statistics data table is created and opened into a new browser window.


Computing a Correlation Matrix

The correlation matrix is a variance – covariance matrix which is standardized in order to emphasise the relative variation between two elements. Raw data is standardized by calculating the correlation coefficient so all elements have a variance of one and a mean of zero. The correlation coefficient is a unit-less number and is the ratio of the co-variance of two elements to the product of their standard deviations.

Correlation coefficient values range from +1 to -1. A correlation coefficient of +1 indicates a direct linear relationship between two elements whereas a correlation coefficient of -1 indicates an inverse relationship between two elements. Correlation coefficients may fall anywhere between these two end values with a correlation of zero indicating no linear relationship existing between the two elements.

For values in the Correlation Matrix that cannot be computed, due to one of the Standard Deviations equalling zero, then a string ‘NA’ will be written in the matrix.

6 Coordinates and Projections 155

6 Coordinates and Projections• Calculating Distances Between Points in Separate Tables

• Displaying Cursor Coordinates in a Map Window

• Updating Coordinates

• Coordinate Transformations

• Reprojecting Coordinates

• Generating Traverse Lines and Peg Coordinates

Calculating Distances Between Points in Separate Tables

Discover>Data Utilities>Distance Calculator

The Distance Calculator can be used to measure the distance and angle between points in two separate MapInfo tables. For example, determine an error distance and bearing between control points in Local and UTM projection when transforming point coordinates.

To effectively utilise this tool, the two tables must share a common field to create the link or join between them; e.g. Control point number. The join must be a one-to-one relationship. One point in the first table can only be linked to one point in the second table.

Note This tool has been primarily designed to work with point datasets. Region or line objects may be used, however the distance and angle will be calculated from the object centroid which may not be satisfactory.


Distance Calculator dialog

Select tables for Distance Calculation

Select the two tables to calculate the distance and angle between using the pull-down lists. Make sure that the correct Key Fields in each table specifying the join are selected.

The distance and bearing are calculated by measuring the object(s) in Table 1 to the object(s) in Table 2 where the objects contain the same attribute in the Key Field. The bearing is determined by using grid north as the datum. The results for the calculation are stored in a new table containing the join key and the Distance and Angle.

Output Options

By default, the output table is saved using the Table 1 name with a “Distances” extension. To change the saved table name or location use the Save button.

When selecting the Output distance units, both metric and imperial units can be used independent to the coordinate system convention e.g. distances between points in a UTM projection can be displayed in miles (mi), yards (yd) or metres (m).


Displaying Cursor Coordinates in a Map Window

See Displaying Map Coordinates, Distances and Bearings.

Updating Coordinates

Discover>Data Utilities>Update Coordinates

Use Update Coordinates to place the coordinate positions of map objects (for example, sample points or collar locations) into data columns in the same MapInfo table. Alternatively, if new survey data has become available, update the position of existing map objects with new coordinates from X and Y data columns in the browser.

The Update Coordinates dialog

Note Calculations for bearing and distance can be perform between most standard MapInfo coordinates systems including geographical, UTM and local coordinate systems.

Add or update map object coordinates into data columns in a browser or update positions of existing points in a map window using coordinates from X and Y data columns in a browser.


Coordinate Update Mode

To update the coordinates held in the table with the current object positions, choose Mapper>Browser. Coordinates may be added to existing numeric columns or to a new column. To add new columns to store coordinates choose New Column from the X Column and Y Column pull-down list. New columns cannot be created if the column name contains spaces.

To update map object locations in the map window with new coordinates stored in the X and Y data columns, choose Browser>Mapper and nominate the X and Y columns containing the coordinates.

For either update mode, select the projection in which the coordinates are to be updated. Auto Projection will calculate coordinate positions for the map objects using the native projection of a table (the projection in which the original map objects were created). Select Other to calculate coordinates in any other existing projection in the MapInfo or Favourite Projections list.

The Other Projection option enables Lat/Long coordinates to be calculated for a table currently containing points in AMG coordinate values. Alternatively, if new survey data is received in a different projection to the existing data, then points can be moved to new positions using this projection data.

When processing a large table, coordinates may be updated more quickly if the table being processed is not displayed as a browser window.

Coordinate Transformations

Discover>Data Utilities>Transform Coordinates

Convert coordinates from one coordinate system to another based on various coordinate transformation parameters.

Note The Update Coordinates utility is best suited to point data but coordinates for polyline and polygon map objects can be calculated using the centroid X and Y coordinates.


Coordinate Transformation dialog

The Transformation Table window lists all of the tables that are currently open in MapInfo to use as the transformation table. Only native MapInfo or TAB files connected to an editable source table can be transformed. TAB files connected to Excel or Text files are Read-Only and will not be displayed in the Transform Table list. Save these tables to native MapInfo tables using the File>Save Copy As menu option and use the saved table for the transformation.

Discover provides two Transformation Targets:

1. E, N data columns - Transform coordinates stored in XY columns according to entered transformation parameters into new data columns in the table

2. Map Objects - Transform map objects (including complex regions and polylines) from one coordinate system to another according to entered transformation parameters.

Transformed map objects are saved to an output table with a “_trans” suffix.

The Discover Coordinate Transformation tool can transform coordinates using one of the following transform methods:

Note Raster images or Grid Surfaces cannot be transformed using the Transform Coordinates utility. For image reprojection, use the Images>Reproject tool; for grid surface reprojection, use the Surfaces>Grid Utilities>Reproject tool.


• Plane – A simple transformation defined by a scaling factor and two pairs of common coordinates or one pair of coordinates and a bearing difference. The plane transformation can provide only rotation and shift.

• Affine – The affine transformation provides for separate scaling, rotation and shift along the X and Y axes. This is an extremely useful transformation and can be used where you need to adjust from an unknown coordinate system such as a local mine grid to a known coordinate system e.g. AMG.

• Projective, Conformal, 2nd order polynomial, 2nd order conformal polynomial and 3rd order polynomial – these options provide for more advanced non-linear transformations for converting from one type of projection to another.

Plane Transformation

Select Plane from the Transformation Type pull-down list. The Plane Transformation option should not be used to convert to or from Latitude/Longitude coordinates. For data in a lat/long projection add two new columns to the table and populate with coordinates in a system such as UTM or AMG using the Data Utilities>Update Coordinates menu option. Make sure the table to transform is open in MapInfo.

1. Select the Data Utilities>Transform Coordinates option.

2. Select the transform projection from the Choose Projection dialog and click OK. The Transform Coordinates dialog is displayed:

Transform Coordinates using a Plane conversion


3. Select Add New Transform from the Choose a Grid Transform pull-down list. Alternatively, load an existing transformation from the pull-down list. When existing transformation parameters are loaded the dialog will be populated automatically.

4. For a new transformation select how the transformation is to be defined. Transformations can be defined by:

Origin, Bearing – Enter the X and Y transformation origin in both original and new coordinate systems. Enter the Bearing Offset between the two coordinate systems into the Old grid from new window.

Two sets of coords - When specifying the transformation as the coordinates of two points in each system enter the Current or original X and Y coordinates for both points overlain by the corresponding New X and Y coordinates for each point.

5. If the E, N data columns Transformation Target was selected in the opening dialog, select the X and Y data columns containing the original coordinates from the Transform Columns pull-down lists. Set the destination X and Y into Columns to store the transformed coordinates using the pull-down lists.

Transform Coords Now

In addition to transforming coordinates from table columns or map objects, single sets of coordinates can be entered for immediate transformation. Check the Transform coords now box. Enter the current X and Y coordinate to transform into the appropriate windows. Click the Calculate button to run the transform calculation. The new coordinates are displayed in the dialog box.

Plane Transformation Scale Factor

When a plane transformation is defined by Two sets of coords (coordinate pair and a bearing offset) then a scale factor must be entered. The scale factor is used to correct for the difference between earth curvature and the map projection used. By default the Scale Factor is set to 1.00.

If the plane transformation is defined by two pairs of coordinates, the scale factor is implicit (as is the bearing offset) and should not be entered.

Note The new X and Y columns must already be available for selection in the transformation table. To add new data columns to the table to store the transformation values use the Table>Maintenance>Table Structure menu option prior to running the Transform Coordinates utility.


A scale factor can be used to convert between coordinate systems in different units. For example, converting imperial coordinates in feet to a metric coordinates system enter a scale factor of 0.3048.

Save Plane Transformation

To save a plane transformation click on the Add button once all the transformation parameters have been entered and supply a transformation name to identify this transformation in the list.

When a previously stored transformation is selected from the list in the top left of the Transform Coordinates dialog, the transformation parameters are applied automatically but cannot be altered.

Plane transformations are saved to a table called LGTRANS (located in the Discover configuration folder) and should be maintained from within this function in Discover. To delete a transformation, open the LGTRANS table into a browser window and delete the corresponding browser record. Transformations can also be modified from the LGTRANS browser window.

Affine Transformation

An affine transformation is used to display MapInfo tables located in a local non-earth grid projection with data in a real-world projection, such as UTM or Lat/Long.

The Discover Transform Coordinates utility enables data to be transformed as a one off process using an affine transformation. Alternatively a custom affine coordinate system can be created and added to the MapInfo projection file as a permanent custom affine projection.

The custom affine projection can be selected for use with tables or as the map window projection just like any other existing projection. The custom affine projection can also be used to map point datasets.

Simple Affine Data Transformation

This process will transform a dataset located in a local non-earth grid projection into a selected real-world projection e.g. Non-Earth (metres) to MGA94 (GDA94) Zone 54

Note Saved transformation parameters can also be used with the Discover>Map Grid and Scaled Output utilities to display a local (non-earth) grid and a map (projected real-world) grid in the same map window.


To conduct a simple affine data transformation, a control point table is required. This is a MapInfo table which contains at least 3 points located in both local non-earth grid and real-earth projected coordinates. The greater the number of control points provided, the more accurate the final transformation (depending on the precision of the control points). Discover uses the control point coordinate pairs to calculate the Affine Transformation parameters.

Example Affine Data Transformation Control Point Table

1. Open the table to transform into MapInfo; this will be located in a local non-earth grid projection e.g. Non-earth (metres).

Note The control point table for a simple affine data transformation must contain four columns, which read in order from left to right as Local_Easting, Local_Northing, UTM_Easting and UTM_Northing. The naming convention of the column headings is not important, but the order of the columns is critical.

Note The control point table for a simple affine data transformation can be used to transform tables from local to UTM coordinates, but cannot be used to create a custom affine coordinate projection line.

See Creating a Custom Affine Projection for further information.


Coordinate Transformation dialog

2. Within the Coordinate Transform dialog, select the table to transform from the Transformation Table list. Choose Affine from the Transformation Type pull-down list.

3. Select the Transformation Target from E, N data columns or Map Objects.

4. Click on the Control Point Table button and browse to the control point table. The selected control point table will be displayed on the Control Point Button. This table does not need to be mappable.

5. Check the Show Transform Parameters box to run the transformation. The transformation parameter, residuals and standard deviation information is saved to a text file named MAPTRAN.LOG in the Discover temporary directory (refer to Discover Configuration). Check the Calculate Parameters only box to display the calculated Transformation Coefficients only without actually transforming the data.


Example maptran.txt report

6. Click OK to commence the data transformation. Select the UTM projection from the Choose Projection dialog.

Once the data has been transformed a new table will be created with the same name as the original transformation table with a suffix “_trans”. This table is automatically opened in MapInfo displayed in map or browser window.

Note The '_trans' table lists the Transformation Coefficents as used by the following affine transformation equations:

x' = Ax + By + C

y' = Dx + Ey + F

Note The maptran.log Total RMS is the total Euclidean distance between the X and Y residual components of the transformation. It does not directly relate to the individual control point's RMSs, and a large value can still be a relatively accurate transformation result depending on the scale and area of application.

The Standard deviation in X and Y indicate a better absolute measure of the error in the transformation.

Note The transformed data table and the original data table cannot be displayed in the same map window. The original table is still located in the local non-earth coordinate system.


Creating a Custom Affine Projection

An affine or custom coordinate system is a custom projection that contains affine transformation parameters and is added to the MAPINFOW.PRJ file. The projection is available for selection when creating and saving tables or setting the projection of a map window.

The data created or saved using the custom projection is still displayed in the local coordinates. The custom projection transformation parameters relate the local grid to real-world coordinates, enabling MapInfo to overlay UTM or Lat/Long data with data collected in the local grid system.

Example Custom Affine Projection Control Point Table

1. Open the table to transform into MapInfo. The transformation table must be mappable and in non-earth local coordinates e.g. Non-earth (metres).

2. In the Coordinate Transform dialog, select the table to transform from the Transformation Table list. Choose Affine from the Transformation Type pull-down list.

3. Set the Transformation Target for Map Objects.

4. Click on the Control Point Table button and browse to the control point table. The selected control point table will be displayed on the Control Point Button. This table does not need to be mappable.

5. Check the Make Affine Coordsys box and click OK. Select the required projection from the Choose Projection dialog.

Note In contrast to the simple affine data transformation, the control point table for a custom affine projection transformation must contain four columns which read from left to right as UTM_Easting, UTM_Northing, Local_Easting and Local_Northing. The naming convention of the column headings is not important, but the order of the columns is critical.


6. Discover will create the affine transformation and add the custom coordinate system description to the MAPTRAN.LOG file.

Example maptran.txt report with Custom Affine Projection line

7. Copy the line beginning “My affine coordinate system” from the MAPTRAN.LOG file and paste into the bottom of your MAPINFOW.PRJ file. The MAPINFOW.PRJ file is located in the ..\\MapInfo\Professional directory.

8. Assign a new name for the custom projection and add a new projection Category line above if desired. This projection category can be used to keep all your custom projections together, and should be in the format below:

"--- Alex’s Projections ---"

9. Add an appropriate bounds clause to the projection line. The bounds clause is used to specify coordinate limits. To specify bounds for the new projection enter the appropriate min_x, min_y, max_x, max_y values for your data as per the example below. Replace the min_x, min_y, max_x, max_y entries with appropriate values for your data. In the following example bounds of -500000, -500000, 10000000, 10000000 have been used.

Example of a custom projection in the MAPINFOW.PRJ file:

"--- Custom Coordinate Systems ---""Sylvania Local Grid", 3008, 13,7, 141, 0, 0.9996, 500000, 10000000, 7, 0.895898, -0.444543, 3108129.02, 0.444537, 0.895887, -6726798.31, -500000, -500000, 10000000, 10000000


Using the custom affine projection in MapInfo

Use this custom projection to create points for data collected in local coordinates, to save data collected in UTM or Lat/Long in local coordinates or to change the map window projection to display local coordinates.

To convert existing polyline or polygon tables in local projection (non-earth metres) so they can be overlain with UTM or Lat/Long data, export the tables as MapInfo MID/MIF files. Open the MIF file in a text editor and change the CoordSys line to the custom coordinate system. (To make sure the correct CoordSys line format is used, export a MapInfo table created in the custom coordinate system as a MID/MIF file and copy and paste the CoordSys line from the MIF file). Once the CoordSys line is replaced import the MID/MIF back into MapInfo.

For more information on creating custom projections refer to the MapInfo Professional User Guide Appendix H.

Reprojecting Coordinates

• Reprojecting a Table

• Reprojecting Multiple Tables

Reprojecting a Table

Discover>Data Utilities>Reproject Coordinates

The Reproject Coordinates utility enables data which is captured in one coordinate system to be reprojected and viewed in a new coordinate system. For example, vector data captured in Australian AGD84 coordinates can be reprojected into GDA94 coordinates. Vector data can be reprojected between projected (e.g. UTM), geographic (e.g. Lat/Long) and custom coordinate systems. The utility works in the same way as the MapInfo File>Save Copy As menu option but has been designed specifically to incorporate the NTv2 grid shift transformation parameters for selected Canadian and Australian projections.

Note Make sure the number after the custom projection name begins with a 30**.If the projection line contains “m” then the custom projection is still in non earth metres and is incorrect. Check the control point table column order is correct and the transform table is in local coordinates.


Reproject Coordinates dialog with NTv2 grid shift option

In the Reproject TAB File dialog select the table to reproject from the Filename pull-down list. Only tables currently open in MapInfo are available for reprojection. The native projection of the table should automatically be populated in the Projection window. If the utility does not recognise the native table projection a warning message is displayed stating that the projection is not listed in the Encom.prj file. See below for details on how to update the Encom.prj file.

By default, a new reprojected table is created using the original table name and a “_reprojected” extension. To change the output file name click on the new name and modify. Alternatively, click on the Browse button and select a new name and/or location for the reprojected table.

Note The projection list available in the Discover Coordinate Reproject utility is stored in a separate file to the MapInfow.prj file. Therefore not all the projections in the MapInfow.prj will be available for selection in this utility. For example, if you wish to reproject data using a custom coordinate system clause which has been added to the MapInfow.prj file you will need to copy the custom projection line into the Encom.prj file located in the .\Program Files\Encom\Common\Projections folder.

Note Check the Use NTv2 grid-shift box when reprojecting images between NAD27 and NAD83 Canadian coordinate systems or AGD66/AGD84 and GDA94 Australian systems. If you are not familiar with this method see Reference Manual: NTv2 Transformation for more information about this option.


Reprojecting Multiple Tables

Discover>Table Utilities>Multi-Table Reproject

Save multiple tables in another projection. All available open tables are displayed in the Tables to Reproject list. Use the Open Table button to add another table to the Tables to Reproject list if necessary. Select the tables to reproject by placing a tick in the table checkbox or use the Select All button. Click in the table checkbox to unselect a table or use the Unselect All button.

Click on the New Projection button and choose the new table projection. This projection will then be displayed in the Target Projection column of the Tables to Reproject window.

A number of options are available to save the reprojected tables. The existing tables may be saved in the new projection or new tables may be created. These new tables will be created in the original table directory unless a different directory is specified. The new tables also have the option to be renamed with a “_reproject” filename extension but this can also be modified to something more applicable if desired. Click OK to reproject the selected tables.

Note Multi-Table Reproject uses MapInfo’s (9.0.2+) method for NTv2 - see Reference Manual: Projections and Transformations for more details. Alternatively you can use Discover>Data Utilities>Reproject Coordinates to perform the NTv2 reprojection on an individual file.


Table Reproject dialog

Generating Traverse Lines and Peg Coordinates

Discover>Data Utilities>Local Grid Layout

The Local Grid Layout option enables a user to quickly and interactively design a local grid over an area of interest. A set of grid points (pegs) and traverse lines with both map (real-world) and local grid coordinates will be generated; these can then be used for geochemical sampling, drilling or geophysical surveys.

Note This routine is not designed to convert coordinates between coordinate systems. For this task use the Coordinate Transformations option described in this section.


A local grid created over a prospective magnetic feature.

To create a Local Grid:

1. Open the background datasets into a mapper window (e.g. interpreted geology, aero-magnetics, gravity, regional surface sampling). Set the view to encompass the target area, and use MapInfo’s Ruler tool to approximately gauge the width (line length) and length (baseline length) of this area.

2. Open the Local Grid Layout dialog.

3. Select the Traverse/Cross Line Orientation option (top left of dialog) and press the Define Interactively on Map button. In the mapper window, draw the initial traverse line by clicking on its start point, and while holding down the mouse button, moving the mouse to the end of the line. Release the mouse to complete the line.


4. This traverse line’s parameters will have been autopopulated into the dialog: it’s X & Y start coordinates, Traverse Line Angle, Line Length and the Projection of the Map Window. Any of these can be manually changed within the dialog, or the line can be redefined using the Define Interactively on Map button.

5. Specify the required Local Grid coordinates e.g. 5000E and 10000N

6. As noted in step 1, specify the Baseline Length, and the required Line Spacing (i.e. distance between grid lines). Press the Calculator button to return the number of lines that will result.

7. Enter the required Peg Spacing: it is likely that you will need to manually adjust the Line Length (captured automatically via Step 3) to accommodate this value (e.g. from 1125.67m to 1200m). Check that the line length is divisible by the peg spacing by pressing the Calculator button


8. Under the Output Options area (bottom right of dialog), use the Save button to specify a name and location for the output files. By default a mappable _Point table will be created detailing every peg in both real world and local coordinates. Enabling the Create Grid as Line File option will additionally create a _Line table comprising a series of attributed grid lines.

9. Enable the Add to Current Mapper Window and press the Preview button at the bottom left of the dialog.

10. To alter the dimensions, spacing or orientation of the grid, simply edit the appropriate parameters in the dialog and press Preview again (this may include redefining the initial grid cross line). Note that if the generated grid lines have been placed on the wrong side of your initial grid line, try changing the Grid Direction side at the top right of the dialog. Also if the grid line you defined interactively is in the middle of the target area, try setting this control to Both.

Local Grid Definition Options

A Local Grid can be defined either by specifying the orientation, length and position of:

• the baseline i.e. a line perpendicular to the required traverse/grid lines. This is generally parallel to anomalism/host rock

• or a traverse/grid cross line, generally perpendicular to the strike of anomalism/host rock

Both options can be defined either by:

• Interactively using the Define Interactively on Map button. In the mapper window, click and hold the left mouse button at the line start point, and drag the mouse to the line end point, releasing the button. The lines X/Y coordinates, orientation, length and mapper projection will be automatically populated into the dialog


• Manually by entering the necessary parameters into the dialog directly, including the required orientation and Projection

Grid Line Parameters

The user can specify any 2 of the following 3 parameters controlling the baseline and the number of cross lines:

• Baseline Length (may be interactively populated)

• Line Spacing (distance between cross-lines)

• Number of cross-lines

To automatically calculate the 3rd parameter, select the toggle to the left of this parameter: the Calculator button will move next to this parameter. Select the Calculator button to return the adjacent parameter.

Grid Parameters

The user can specify any 2 of the following 3 parameters controlling the grid cross lines:

• Line Length

• Peg Spacing (distance between grid pegs along each line)

• Number of Pegs

To automatically calculate the 3rd parameter, select the toggle to the left of this parameter: the Calculator button will move next to this parameter. Select the Calculator button to return the adjacent parameter.

Note The Local Grid Layout tool does not support Latitude/Longitude projections; ensure that the mapper window is in a UTM projection system.

Note If the Baseline Length has been populated via interactive definition, it will probably need to be manually adjusted so that it can be divided by the Line Spacing. Check this by using the Calculator on the Number of Lines field.


Output Options

The Local Grid Layout tool will generate a table called tablename_Point, where the tablename is specified using the Save As button. This mappable table will contain a point for each output grid peg, attributed with the following fields:

• PegNum – Peg number

• Line – Line number

• LocalX – non-earth easting coordinate

• LocalY – non-earth northing coordinate

• East – easting coordinate in the specified UTM projection

• North– northing coordinate in the specified UTM projection

If the Create Grid as Line File option is enabled, an additional mappable table tablename_Line will be created, containing a series of attributed grid lines attributed with the Line and LocalY fields.

Note If the Line Length has been populated via interactive definition, it will probably need to be manually adjusted so that it can be divided by the Peg Spacing. Check this by using the Calculator on the Number of Pegs field.


The output grid line file, labelled with the LocalY field.

If a map window other than the original mapper window is made active, enabling the Add to Current Mapper Window option and pressing Preview will add the local grid to this window. This can be useful when displaying different datasets of covering the same area in different windows (for instance using the Discover>Map Window>Map Linking and Cursor Position options).

Advanced Options

The Advanced Options button provides the following controls:

• First Line No. – allows the initial line number in the output Line field to be set (default 1)

• First Peg No. - allows the initial peg number in the output PegNum field to be set (default 1)

• Peg No. increment - allows the peg number incrementation (default 1) to be altered (e.g. to 10, 20, 30,...)

• Peg No. Prefix – add a prefix to the peg numbers e.g. RH530, RH531, RH532…


• Peg No. Suffix – add a suffix to the peg numbers e.g. 34 west, 35 west, 36 west

• Peg numbers can be set to increase up one line, then follow back down the net line (i.e. zig-zag)

• Alternate grid lines can be offset, allowing the creation of triangular/diamond grids. To accomplish this, specify an offset of half the Peg Spacing.

A triangular grid created using the Offset option under Advanced Options

7 Managing Maps and Layers 179

7 Managing Maps and LayersEncom Discover provides you with a flexible and powerful way of working with Map windows and layers. The Enhanced Layer Control (ELC) allows you to manage multiple map windows from a single control.

The ELC allows you to operate on all open map windows from a single control. It is a persistent control that remains visible as long as you want it to and provides easy access to all the standard MapInfo layer control functions.

Layers can be organised in natural groupings that can be independent of their display order, and aliases can be used to provide a more natural and consistent naming of data. Multiple layers can be selected and operated on simultaneously.

The ELC also provides complete control over the standard layer attributes such as editability, visibility and label display.

• Opening and Closing the ELC Window

• ELC Window Controls

• Configuring the ELC

• Using the ELC

• Layer Aliases

• Layer Groups

Opening and Closing the ELC Window

When you first load Discover, the ELC is displayed in a floating window that you can position and resize as required.

To roll-up, unroll, minimize and restore the ELC window:

• To roll-up or unroll, double-click the ELC title bar

• Click the minimise and restore up buttons on the title bar to minimize the ELC window to any position on the screen and then restore it back to the original position.

If the ELC is not displayed, click the ELC button on the Discover toolbar. To close the ELC, click the close button on the title bar. You can also show the ELC from the Discover menu.


To automatically start ELC when Discover starts:

1. On the Discover menu, point to Configuration, and then click Settings.

2. Under Automatic start, in the Auto-start modules section, select On (auto).

You can also change the auto-start property by clicking the Options button on the ELC and selecting Open automatically on startup.

ELC Window Controls

The ELC displays information as a two-level hierarchy. The top level describes the map windows and the second level describes the layers contained within them. If you have open Browsers, Layout Windows etc. they are also displayed and can be controlled by the ELC.

The ELC is operated by clicking the controls in the ELC window and from a number of shortcut menus:

Map windowCosmetic layer

Layer

Click to expand and contract map tree


Controls

Control Name Usage

Visibility Select or clear the check box to show and hide maps and individual layers.

Editable Click to toggle layer editability.

Selectable Click to toggle layer selectability.

Auto-Label Click to toggle layer labelling on and off.

Zoom to Extents Click to zoom to the extents of the layer or all layers.

Apply Changes Apply the changes to the map window. See Configuring the ELC.

Refresh Refresh the ELC window.

View Groups Click to toggle between standard and grouped views. See Layer Groups.

Zoom Previous Restore previous views. Every time you click this button the map window is redrawn to the previous limits. If the window size was changed in a previous view, the view is centred and displayed at the previous scale.

Options Display ELC Options. See Configuring the ELC.

Note Cosmetic layers are always visible—you cannot hide them from the ELC.

Note The Discover>Map Window>Make Selected Layer Editable is a useful shortcut to making the layer on which objects are currently selected editable. This is especially useful where there are many layers in a map. This option is only available when running MapInfo Professional versions earlier than 9.5.


Shortcut Menus

For more information, see Using the ELC.

Configuring the ELC

You can change the way the ELC interacts with your Map windows. The options available include:

• Apply changes instantaneously or only after you have made a number of changes to the ELC.

• Display layer information for all open Map windows or just the acti ve Map window.

• Display layer aliases or the .TAB file names.

• Display layers by user-defined groups or in the standard layer view.

• Expand all open Map windows, or only the active Map window.

• Autostart ELC.

• Manage Discover 3D windows with the ELC (if installed)

• Set field names fro aliases and groups.

To configure the ELC:

1. Open the ELC and click Options.

2. Select or clear the options as required. For information about the options available, see Reference Manual: Layer Control Options Dialog Box.

Do this To display

Right-click anywhere inside the ELC window away from maps, layers and other controls.

ELC shortcut menu

Right-click a map. ELC Map shortcut menu

Right-click a layer. ELC Layer shortcut menu


Using the ELC

You can perform a wide variety of tasks from the ELC. If the Apply Changes button is not available, the ELC will apply your selections instantaneously (see Configuring the ELC). Otherwise, selections made in the ELC will only be applied when you click Apply Changes.

Many commonly used tasks can be applied directly from the window controls. For a description of these controls, see ELC Window Controls.

When you right-click on a map or a layer or another part of the ELC window, different shortcut menus are displayed. From these menus, you can perform a wide variety of tasks. For more informatiion, see Shortcut Menus.

You can change the display order of layers and move layers to another Map window by selecting the layer in the Map tree and dragging it to another position in the tree. To select multiple layers, hold the CTRL key and click each layer, or hold the SHIFT key and select the first and last layer in a group.

Shortcut Menus

From the ELC Shortcut Menu (right-click inside the ELC away from the maps, layers and controls), you can:

• Open any table or open a table from your favourites list.

• Add, order and remove favourite tables.

• Change ELC options.

From the ELC Map Shortcut Menu (right-click a map), you can:

• Open a table.

• Add and remove layers.

• Change Map window properties and size. This option is especially useful when a window is drawn off the visible screen.


From the ELC Layer Shortcut Menu (right-click a layer), you can:

• Select and unselect objects in a layer.

• Add and remove layers.


• Create a stacked profile.

• Create and manipulate grids.

• Open and close tables.

• Open Mapper and Browser windows.

• Modfy the display properties of themes, objects, and labels.

• Control layer and object hotlinks.

• Display the projection parameters.

• Switch between layer aliases and table names.

• Remove alias names and group names.

• Add the layer to the favourites list.


The options displayed in the shortcut menu will depend on the type of layer, or layers, selected.

Layer Aliases

It is often convenient to refer to a layer with a name that differs from the name of its associated .TAB file. For example, you might have three .TAB files called:

area2_Collars_all_exp.tabarea2_lab1_assays_12-05-2001.tabarea2_StreamSamps.tab

Which would appear in the ELC as:


Actual TAB file names displayed in the layers

You can define more meaningful aliases for these tables, such as Assays, Stream_Samples and Drillholes, which would appear as:

The ELC with aliases used instead of the .TAB file names to better describe the layer content.

To create an alias for a layer:

1. In the ELC, click Options and ensure Use layer name aliases is selected.

2. Double-click the layer name in the ELC and then type or edit the alias.

3. Press ENTER.

The alias is saved as metadata in the .TAB file.


To show aliases or revert to table names:

• To show alias names in the ELC map tree, in the ELC, click Options, and then select Use layer name aliases. Clear this check box to display table names.

To remove an alias:

• In the ELC, right-click the layer, and click Reset Alias Name in the shortcut menu.

Layer Groups

With the ELC you can organise your layers into user-defined groups, independent of the drawing order of the layers.

For example, a Map window might contain the following layers:

Geochemical samplesOutcrop samplesVeins and dykesFaultsTownsElevation pointsElevation contoursDrainageRoadsRailwaysMining LeasesExploration AreasNational ParksGeological unitsMagneticsGravity

Some of these layers contain points and labels, others contain polylines, and some contain filled polygons. And there are images also, which are used as backdrops.

Note Layer aliases will only work in the ELC and some of Discovers dialogs. All MapInfo dialogs will show the name of the original table (.TAB file) even when an alias name has been set.


The order of these layers in the standard MapInfo layer control (and in the ELC in its default mode) corresponds to the order in which the layers are displayed by MapInfo. Images such as gravity, magnetics, and geology are displayed at the base of the map window so they do not obscure the other vector layers. Above the raster layers are polygonal layers, for example, National Parks, Exploration Areas and Mining Leases. Overlying the polygonal layers are tables comprising linework such as railways, roads, drainage, elevation contours, and veins and dykes. And above those are point layers such as towns, geochemical samples, outcrop samples, and elevation points.

Instead of ordering the layers by their drawing order, it would be more instructive to group them according to what they contain, for example:

The ELC allows you create groups and then order the layers in the Map tree into these groups.

To enable layer groups:

1. In the ELC, click Options.

2. Select the Allow layer logical grouping check box.

Samples Geochemical samplesOutcrop samples

Geology Veins and dykesFaultsGeological units

Geophysics GravityMagnetics

Topography Elevation readingsElevation contours

Infrastructure TownsRailwaysRoadsDrainage

Leases Etc. Mining LeasesExploration AreasNational Parks


To create a group:

To rename a group:

• In group view mode, double-click the group name and edit or type a new name.

To switch between group and standard view modes:

To remove a group:

• Right-click a layer in the group and, from the shortcut menu, click Reset Group.

To show and hide all layers in a group:

• Select or clear the group visibility check box.

The grouped view is a powerful feature when you have a large number of layers and you only want to display a few of them. Instead of showing and hiding individual layers, you can organise all of them in a single group and then, when you want to change from one set of layers to the next, hide the current group and show another.

1. In the ELC, click the View Groups button.

2. Right-click any layer and, from the shortcut menu, select Add Group.

3. Type the group name and replace the default name.

4. Select and drag the layers you want into the new group.

• Click the View Groups button.


The ELC showing Groups with associated layers

Limitations of the Grouped View

When you associate a group name with a layer, the name is stored as a metadata key in the corresponding .TAB file. This restricts the way in which you use Groups as follows:

1. A layer can only belong to one group.

2. If a layer has been included in a group, then all layers (in all map windows) that are attached to the same .TAB file, exist within the same group.

3. You cannot control the order that groups are displayed in a grouped view. They are displayed in alphabetical order.

8 Working with Map Objects 191

8 Working with Map ObjectsIn this section:

• Objects and Layers

• Creating Objects from a Table

• Creating and Editing Objects from the Keyboard

• Selecting Objects

• Copying, Moving and Transforming Objects

• Manipulating Lines, Polylines and Polygons

• Using Polyline and Polygon Attributes

• Conditioning and Converting Linelwork into Polygons

• Colouring Map Objects

• Formatting Vector Objects

• Cloning Object Styles

• Linking Objects to External Documents

See also...Digitizing and Data Entry...Selecting Table Records...Working with Tables

Objects and Layers

Before creating and editing objects in a map, the layer on which it is stored must be selectable and editable. Use the Enhanced Layer Control (ELC) tool to manage the properties of layers in a map.

The Discover>Map Window>Make Selected Layer Editable tool is a useful shortcut to making the layer on which objects are currently selected editable. This is especially useful where there are many layers in a map. This option is only available when running MapInfo Professional versions earlier than 9.5.


Use the Discover>Map Window>Distance and Bearing tool to display the browser entries for objects in the selected table continuously as the cursor moves over the objects in the map window.

See also...Managing Maps and Layers...Displaying Map Coordinates, Distances and Bearings

Creating Objects from a Table

Discover>Table Utilities>Build Objects from Table

Create MapInfo objects from descriptions stored as ASCII coordinates in MapInfo tables or text files.

If you have object descriptions other than points in a text file (in general a list of X and Y coordinate pairs), the only way MapInfo can import these objects is if the data is initially converted to a MapInfo Interchange Format (MIF) or Drawing Exchange Format (DXF) file. In most cases this is an impractical course of action. Discover provides the ability to create objects from a variety of ASCII description types.

In order to use ASCII coordinate data with Discover, the text file should be opened as a table in MapInfo. For large files, save the ASCII coordinate table to a native MapInfo table for quicker processing.

For all import formats the coordinate system of the ASCII data must be known. When importing polyline descriptions, there is the option to convert closed polylines to regions for appropriate formats. Regions are then created with the current pen and brush styles.

Note To build objects from Geographical or Longitude/Latitude coordinates, the data structure must be in a decimal degree format. The Build Objects from Table tool will not accept Degrees, Minute, Second (DMS) data format. To quickly reformat the DMS data, use the MapInfo tool located under Tools>Tool Manager>Degree Converter.


Build Objects from Table options dialog

Row Delimited Polylines

Polyline descriptions must have a delimiter to enable Discover to determine when the last node in an object has been read. The delimiter may be either a line between the objects (blank or otherwise), a change in attribute (such as polygon code) or a value such as “start” or “end” entered into another column. For each of these cases it needs to be specified which columns contain the X and Y coordinate information.

If the polylines are delimited by row then Discover must know whether to expect a blank line or a line with a different value in the X or Y coordinate column. Use the Row delimited Polylines to import objects in the Arc Line format, where the start delimiter line is a sequential record number and the end delimiter line is “END”.

Example of polylines without attributes delimited by a blank line

317822 6994520317911 6999620309400 7001427309400 6994833233410 7665412236410 7665499236410 7668390233410 7668211


Import Polylines using row delimiters options dialog

Column Delimited Polylines

If the polylines are delimited by column, Discover must know which column contains the delimiter and in what form the delimiter takes. Choose the Unique Attribute option if each node in a polyline is identified by the same attribute value. Use Start Keyword if the start of each polyline is identified by a word such as START, or use the Start and End Keywords if both the start and end of each polyline are identified. If using the start/end keyword options, enter the appropriate keywords for Discover to search for.

Example of polylines delimited by a unique identifier in column 1

EL877 317822 6994520EL877 317911 6999620EL877 309400 7001427EL1234 309400 6994833EL1234 233410 7665412EL1234 236410 7665499EL1234 236410 7668390EL1234 233410 7668211


Import Polylines using column delimiters options dialog

Discover provides the option of importing data either as normal X and Y coordinate pairs or as distance, bearing and elevation triplets. For the latter, the distance is taken to be measured in the current coordinate system units, the bearing is between 0º and 359º, and the angular elevation is between +90º (uphill) and –90º (downhill). If angular elevations have not been measured then Discover assumes the traverse is flat.

For both import options, Discover attempts to include any other values found on the first line of the object description as attributes in the MapInfo table.

Line on One Row Polylines

The Line on 1 row ASCII import format contains line descriptions with the coordinates of the two endpoints of the line in one row of the import file/table, as X1, Y1, X2, Y2. For example:

805600, 8475240, 805600, 8475260

If there are any attributes in the ASCII file, they are not carried across to the MapInfo table.


XYZ Grid

XYZ grids generated by other gridding programs such as Surfer can be imported using Discover. The grid cell size is automatically detected from the X,Y coordinate pair spacing and the grid is created as polygons centred on each X,Y point. The Z-value is added as an attribute to each object to generate a table similar to that produced by the Discover Surfaces module. The imported grid can then be thematically shaded.

Creating and Editing Objects from the Keyboard

Discover>Object Editing>Key in Shapes

Usually when creating map objects, you can draw them using a digitiser or mouse. However, in some cases you may have an object description in coordinates (such as a property or tenement boundary) or you may wish to create a polyline or region from a distance/bearing/elevation traverse.

Using Discover, you can enter coordinates directly from the keyboard and build simple objects, such as ellipses, points or lines, or more complex multi-node polylines and polygons. You can also edit the shape of existing objects by altering the node coordinates.

If you have a list of coordinates already in a text file, use the Discover>Table Utilities>Build Objects from Table function to create objects automatically from these coordinates.

If the object that you have defined lies outside the map window extents, the map window is panned to show the object.

Selecting the Object Type

In the Key in Shapes dialog, select which map layer in which you wish to create the new object (choose from any layers in the map window or choose to create a new table). Discover then uses the projection of the current map window to draw the objects. You can easily change projection by selecting a projection with the Favourite Projections option.

Note This import option produces a grid of MapInfo polygons. Use the Discover Surfaces>Import Grid File>ASCII Grid to import an ASCII grid into one of the supported raster grid formats.

Create map objects by entering node coordinates from the keyboard. Edit the node coordinates of a selected object.


Drawing objects by coordinates dialog

You should then nominate the type of object to draw, the units to use and how to specify nodes for polylines and polygons. If the map window is in a lat/long projection, the XY Units control is set to Degrees and disabled. If you are entering coordinates in degrees, select between decimal degrees and degrees, minutes, seconds (DMS). DMS format is dd.mmss, for example 47º 17’ 23.45” would be entered as 47.172345.

The dialog for entering the coordinate information depends on what type of object you have nominated to draw.

Draw a Point

Select Point as the Object Type and use the Object Style button to select an appropriate point symbol. Click on the Enter Coordinates button and key in the X and Y coordinates into the Draw Point dialog. Click OK to create new point.


Draw a Line

Select Line as the Object Type and use the Object Style button to select an appropriate line style. Two options are available for drawing line objects: Enter Nodes by Coordinates enables a user to enter the start and end coordinates of the new line. Enter Nodes by Distance, Bearing enables the user to specify a starting coordinate for the line and then a distance, bearing and inclination to the end point of the line. Choose the Enter Coordinates button to enter the line information into the Draw Line dialog:


Draw a Polyline/Polygon

Select Polyline or Region as the Object Type and use the Object Style button to select an appropriate line/region style. Two options are available for drawing polyline or region objects: Enter Nodes by Coordinates and Enter Nodes by Distance, Bearing. Once the appropriate option has been selected, click on the Enter Coordinates Button.

Enter Nodes by Coordinates

Enter Nodes by Coordinates enables a user to enter a coordinate pair for each polyline or region node. Use the Add button to add a coordinate pair to the list, and the Edit/Delete buttons to modify the Current Nodes list. When you have entered all the nodes for the object, click the Done button and the object is constructed in the appropriate map layer.

The dialog for entry of metric polyline/polygon nodes

Enter Nodes by Distance, Bearing

Enter Nodes by Distance, Bearing enables the user to specify a starting coordinate for the polyline or region and then a distance, bearing and elevation to the next node. Click the Add button, and the coordinates of the first two points are placed into the Current Nodes list.


Leave or enter the next distance/bearing/elevation value and click Add to place the coordinates of the next point in the list. If you do not have measured elevations, then leave these as zero. Otherwise, Discover uses negative elevations for down and positive elevations for up.

The dialog for entry of metric polyline/polygon nodes using Distance/Bearing/Elevation

Draw an Arc, Ellipse or Rectangle

Select Arc, Ellipse or Rectangle as the Object Type and use the Object Style button to select an appropriate line/region style. Click on the Enter Coordinates button.

To draw an ellipse or rectangle, the diametrically opposed corner coordinates of the object need to be entered. To draw an arc, the diametrically opposed corner coordinates of the arc need to be entered, along with the start and end angles for the arc.


Edit Node Coordinates

If you have an object selected when you choose Key in Shapes, Discover allows you to edit the existing node coordinates with the same methods described above. When editing a polyline or polygon, the Add button allows you to add a node at any position within the object. You are asked where to place the new node, and the coordinates are then added to the node list. You cannot create or edit multi-section polylines or regions using this tool in Discover.

Selecting Objects

• Select by Proximity

• Select All Objects in Editable Layer

• Select by Graphical Style

Select by Proximity

Discover>Data Utilities>Proximity Search

Display map objects that are located within a specified distance from one or more selected objects. Apply additional filter criteria to returned map objects to refine proximity search.

The Discover Proximity Search enables identification of map objects of interest due to their spatial relationship to other map objects. For example, a Proximity Search could be used to identify geochemical samples that are located within 2 km of an old mine site. The search can be further refined to only identify samples that have a gold grade greater or equal to 2 ppm. Alternatively, perform a Proximity Search for all significant copper occurrences that fall with 2 km of a selected fault(s).


Create a proximity search for mineral occurrences around a selected fault

1. Select the map object or map objects to search around, e.g. faults.

2. Choose the layer in the map window that is to be returned in the proximity search (e.g. mineral occurrence layer). Enter a search buffer Width and appropriate Units to use. The Resolution value relates to the number of segments used to create the buffer. The higher the resolution, the smoother the appearance of the buffer. To view the buffer check the Show buffer box and choose an appropriate Line Style.

Note You can choose more than one object to perform the proximity search around. To quickly select all map objects in a layer highlight the layer in the ELC and choose Select All from the right-mouse click pop-up menu.


The Proximity Search will only select map objects that are located within this buffer zone. If a number of adjoining map objects are selected one search buffer is created that covers all the adjoining objects.

3. To refine the selected map objects further check the Where box and use the column and operator pull-down lists to create an expression similar to that used in an SQL “Where” condition. This expression informs Discover to only select map objects located within the buffer that meet the specified selection criteria. For example, where the copper grade is greater than or equal to 2 ppm the mineral deposit type equals Au, etc.

4. The search results may be saved to a user defined file name and location. Otherwise the results will automatically be saved to a temporary table named PROXSRCH. Selected records may be displayed in a browser and/or added to the current map window.

Specify a unique map object style to display the selected objects in the map window.

5. Click OK to commence the Proximity Search.

If the Show buffer box is checked the search buffer is placed into the Cosmetic layer and may be removed at any time. Existing buffers are not erased by Discover when the Proximity Search is run again.

In the example shown above, each fault is made up of 5 to 10 separate polylines. When they are all selected, a buffer is created around all adjoining lines.

Use the Discover>Data Utilities>Line Orientation tool to insert the fault orientation as an attribute for each fault line and then create proximity searches to find mineral deposits or samples close to specifically oriented fault lines, e.g. 40º - 60º.

Select All Objects in Editable Layer

Discover>Map Window>Select All from Editable Layer

This menu choice is useful if the editable layer is not the top selected layer. The option allows you to select all the map objects in the currently editable layer in a single step.

Note This option is only available when running MapInfo Professional 9.5 or later.


Select by Graphical Style

Discover>Map Window >Select by Graphical Styles

The Select by Style dialog displays the style of the selected object and allows the selection criteria to be altered. By default, Discover selects all objects with exactly the same style from the same layer as the selected object. You can refine the selection criteria to request Discover to select, for example, symbols of the same colour but of any shape or size, or regions of a particular fill colour regardless of the fill pattern or line style.

To all objects of the same style from a table -

1. With the Select by Style dialog open, select a graphical object from the map window - all object types are supported including symbol, lines, polygons and text. An object in the cosmetic layer may also be selected.

2. Click Get selected object Style. The object's properties will be displayed in the dialog.

3. Select which properties to select by. By default all available properties will be used.

4. Now choose which table to search for matching objects from the pull-down list. This can be the same as the selection table or different table, but not the cosmetic layer.

5. By default the output selection will be named the table name plus "_selection" but this can be altered. The resulting selection can be opened in a new browser and/or map window.

Select by Graphical Styles allows you to select all objects from a table that have the same graphical style attributes as the selected object.


Select by Style dialog

Copying, Moving and Transforming Objects

• Offsetting Copies of an Object

• Moving, Scaling and Rotating Objects

• Aligning Objects


Offsetting Copies of an Object

Discover>Object Editing>Offset Object

Create multiple copies of a selected object at nominated offsets in the X and Y directions. The selected object can be of any type. Attributes can be copied from the “seed” object to the offset objects.

Create up to 10,000 objects offset from the selected object by specific distances in the X and Y directions. Enter X and Y offsets (positive values are up and to the right, negative values are down and to the left) and the number of objects to create in the X and Y directions (up to 100 in each direction). Discover then creates a matrix of objects.

Check the Retain attributes from selection box to populate the new object records with the browser attributes from the seed object.

Duplicating an object (left) by offsetting it in both the X and Y directions (right)

Offset


Use this feature to quickly create a table of mapsheet boundaries. You can create the “seed” object by using the Discover Key in Shapes tool to enter exact coordinates for the mapsheet object, and then use Offset Objects to create a full coverage of mapsheets. The mapsheet boundaries can then be used in Scaled Output to quickly produce a hardcopy map just for a specific mapsheet. Examine the MAP250K table in the .\DISCOVER TUTORIAL\OTHER DATA directory for an example mapsheet table (you should create the boundaries as regions rather than rectangles so they can be re-projected).

Moving, Scaling and Rotating Objects

Discover>Object Editing>Transform Objects

Transform one or more objects by applying shift, scale and/or rotation.

The Discover Object Transform function provides a simple method to transform multiple objects. This could be used in circumstances such as rescaling map annotation for a different output scale or shifting and rotating all map annotation for a different map projection.

Discover allows you to perform up to three transform procedures together – for example rotation followed by a scale and a shift.

Note You can offset an object by degrees even if the base projection of the layer is in metres.

Note The order in which scaling and rotation operations are carried out may produce differing results.


• Shifting – Specify the distance in metres in the X and Y direction to move each object by. Similar to map units, positive values increase the eastings and northings.

Moving an object by shifting it on both the X and Y directions

• Scaling – Specify the scaling factor for each object. Choose equal scaling in X and Y to retain the object aspect ratio. You also need to specify the basepoint position for each object, where the scaling is to be anchored.

Scaling an object uniformly by specifying equal X and Y axis ratios

• Rotation – Specify the angle to rotate each object by, in degrees anticlockwise from North (use negative angles to rotate clockwise). You also need to specify the basepoint position for each object, about which the rotation is performed.

Object rotation

Move

Scale

Base

Rotate

Base


The following points should be born in mind when using Object Transform:

• Transformation of each object is relative to a basepoint in each object.

• If you want to scale and rotate objects relative to one common point, use the Discover>Data Utilities>Transform Coordinates function.

• Scaling of points is not meaningful.

Aligning Objects

Discover>Object Editing>Align Objects

The Discover Align Objects tool enables two or more map objects to be aligned with respect to each other in a map window. Use the Align Objects tool to create professional looking legends by aligning legend map objects and text descriptions.

Any type of map object or combinations thereof including points, lines, polylines, polygons/regions or text may be aligned. To align map objects simply select the map objects using any of the MapInfo selection tools and select the Object Editing>Align Objects menu option. The Align Objects dialog is displayed:


Align Object dialog

Map objects can be aligned with respect to each other vertically or horizontally. When aligning map objects all selected objects will be aligned with the map object that has the greatest extent according to the alignment selected. For example, a Left Vertical alignment will align selected map objects with respect to the selected map object which is located the furthest to the left/east in the map window. The opposite applies for the right/west of the map window for a Right Vertical alignment. Vertical Centre alignment will align selected map objects with respect to the centre of the selected map object with the greatest horizontal extent in the selection.

Applying Vertical Centre and Horizontal Centre alignment options to map objects (left)

Align


results in the smaller object aligning itself to the larger map object (right).

Map objects can also be aligned with respect to each other in a horizontal direction. Top Horizontal alignment will align selected map objects with respect to the selected map object which is located the furthest to the top/north in the map window. The opposite applies for the bottom/south of the map window for a Bottom Horizontal alignment. Horizontal Centre alignment will align selected map objects with respect to the centre of the selected map object with the greatest vertical extent in the selection.

To equally distribute a group of map objects along the Vertical or Horizontal axes, use the Disperse Vertical and Disperse Horizontal options. For example, if 5 objects are selected to be dispersed horizontally, the 3 intermediary objects will be distributed evenly between the X coordinates of the two end-member objects.

Note that for the Disperse option, coincident points (where the centroids of multiple objects are identical) can either be treated as:

• Separate points (default), or

• As a single point so they are not separated. This is enabled by the Keep coincident points coincident when dispersing option.

If the position of the aligned map objects is not correct use the Undo button to return the map objects to their original position. The Undo button will only undo the last alignment and only if the original selection has not changed.

Manipulating Lines, Polylines and Polygons

• Smoothing

• Thinning

• Cutting

• Joining

• Inserting Nodes

• Changing Line Direction

• Creating Donut Polygons

• Clipping

• Splitting Multiple Polylines and Polygons


Smoothing

Discover>Object Editing>Polyline Smoother

The line smoother works by interpolating a spline curve through the selected polylines and adding nodes where necessary. This is in contrast to MapInfo’s smoothing which is a running average type smoothing and operates on-the-fly. Discover stores extra nodes for a smoothed polyline.

Use of the Polyline Smoother: the original polyline of the left, and the smoothed output on the right

Poor results are obtained when a minimum number of nodes define a polyline. For example, if a polyline in the shape of a rectangle is defined by only four nodes, the line smoother modifies the fundamental shape and produces an elliptical shaped polyline.

The polyline smoother can be used to overwrite a polyline with the smoothed line or write the smoothed line to a separate table. If the smoothed polyline is written to a different table, then data attributes are only carried across with the polyline if the structure of the two tables is identical.

Discover does not smooth polygons, because of the danger of destroying topology relationships between adjacent polygons that share boundaries. In general, if such polygons are smoothed, then the resulting boundaries have small areas of gaps and overlap.

The Discover Polyline Smoother is designed to improve the appearance of digitized linework by smoothing abrupt changes in direction.


Thinning

You may wish to use the thin polyline options when you are using detailed data at a much smaller scale than it was digitised at. For example, you may wish to make a less detailed copy of a complex piece of coastline. Discover provides two methods of thinning polylines as outlined below:

Thin Polyline by Node Number

Discover>Object Editing>Thin Polyline by Node Number

Decrease the number of nodes in the selected polylines or regions by removing every nth node.

Node Thinning dialog

Select the polylines or regions to thin (use any of the MapInfo selection methods) and then nominate a node thinning factor. Discover allows you to discard from 5% (1 in 20) to 95% (19 out of every 20) of the nodes in the selected objects.

This method of thinning polylines and regions may not produce acceptable results on some data sets such as geological boundaries and you may need to use the second thinning method described below.

Discover allows you to calculate statistics on the selection of polylines before you nominate a thinning factor. If you wish to retain the original, more detailed, data set make sure to save the processed data under a different name. Use the MapInfo File>Save Copy As menu option.

Note Do not thin regions that have adjoining regions as common boundaries will not necessarily remain the same.


Thin Polyline by Node Position

Discover>Object Editing>Thin Polyline by Position

Decrease the number of nodes in the selected polylines or regions by removing those nodes that lie within a tolerance angle of adjacent nodes.

Use this method of thinning nodes in a polyline or region for most natural and geological map objects such as contours or geological boundary lines.

Node thinning by scale or size

You define the sub-sampling to be carried out on the selected objects by specifying either a thinning width or a thinning scale. For a nominated thinning width, Discover examines the first 3 nodes in the object. If the second node lies within the thinning width of a line joining the first and third nodes, then it is discarded, otherwise it is kept and the second to fourth nodes are examined.

For the thinning scale, the same process is carried out with a thinning width implied by the specified scale. The thinning width is calculated as 1 thousandth of the specified map scale, so that for a map scale of 1:10,000 a thinning width of 10 m (or whatever current units are in use) is implied.

Use the Thin for scale option when you know what scale you are viewing your data at. Otherwise, use the Thinning width option if you know what size features and level of detail you need to retain.


Cutting

Discover>Object Editing>Line Cut

Using the MapInfo Objects>Split menu option, you can cut objects where they intersect a cutter region. In many cases this is cumbersome and requires that a region be specially constructed for the purpose from existing polylines. With Discover, you can use a line, polyline or arc as the cutter object to split polylines or regions. If the object that you want to split is not a polyline or a region, it is converted to one and then split. Therefore splitting an arc object will result in the creation of two polylines. Discover cannot split text or point objects.

When you have selected the objects to cut, choose the Object Editing>Line Cut menu option. Discover then prompts you to select the line to perform the cutting operation. As soon as you have selected a line, Discover carries out the cutting operation.

If Discover displays a message such as “An error occurred overlaying nodes”, the cutting operation is not completed and you should check the results.

Joining

Discover>Object Editing>Line Concat

Join lines within a specified distance and angle of each other.

Line or polyline data such as drainage, roads/tracks, pipelines or other utilities can sometimes be received as a series of disjointed line segments whereby it is necessary to combine them into single objects. The Discover Line Concat utility enables line segments which are located within a specified distance and within a specified angle from each other to be combined into a single continuous linear object.

The lines or polylines to be concatenated must be selected in the map window prior to choosing Line Concat from the Object Editing menu.

Cut any object (except points and text) with a line that crosses the object. Select the objects to cut, choose the menu option and select the cutting line to execute the cut.


Line Concatenate options

In the Concatenation Parameters enter a maximum distance in which to join lines. Enter a maximum angle between line segments to join. Lines will be joined where the start or end node is within the entered distance and angle to the start or end node of another line segment. Options are available to stop joining lines where multiple line options are found within either the entered search distance or angle. This will prevent incorrect joins being automatically created but may require some manual editing using the Line Concat tool at a later stage.

Another way of filtering the lines to join is to use an attribute field. Lines will only be joined which are within the entered search distance and angle and which have the same attribute value; e.g. drainage classifications or utility types. To use this option check the Join lines by value in column box and select the attribute field from the pull-down list.

The resulting concatenated lines may be created in the original line table or check the Operate on copy of data box to create a new table containing the joined linework.


Line segments to concatenate

Resulting concatenated lines

Inserting Nodes

Discover>Object Editing>Insert Nodes

Insert nodes at specified intervals from the beginning of a line or into polylines/polygons at regular spacings between existing nodes.

Note If the joined lines are created in the same table, the MapInfo File>Revert Table menu option can be used to return to the original segmented line work so long as the table has not been saved. If it looks like there are still joined lines after using this menu option, zoom in the map window to refresh the view.

To remove deleted (grey) rows from the browser of the original table select File>Save Table and then Table>Maintenance>Pack Table.


The MapInfo Add Node utility only allows one node to be added at a time to an object. The Discover Insert Nodes utility enables multiple nodes to be added to line, polyline or polygon objects in a single pass.

In certain situations it may be necessary to increase the density of nodes within a polyline or polygon object. For example, when gridding contour or other line data and when performing detailed object editing whilst digitizing. Aside from increasing node density between nodes in existing polyline or polygon objects, nodes can also be inserted at specific intervals along a straight line object. This option could be used to plan geochemical sampling programs or ground geophysical surveys.

Nodes can be inserted into a map window selection or in all objects in a table. If a map window selection is used, select the objects prior to choosing Insert Nodes from the Object Editing menu.

Once you have selected the objects into which the nodes are to be inserted, the Insert Nodes dialog is displayed.


Two Insert Node Options are available:

• Insert Nodes at fixed intervals from start of line

Use this option for line objects (lines with start and end nodes only). Enter the desired interval into the Enter Maximum Node Spacing window and choose the appropriate units from the pull-down list.

• Insert Nodes at regular intervals between existing nodes so interval does not exceed maximum node spacing

This option will initially measure the distance between the existing nodes and if the distance between these nodes exceeds the distance entered into the Enter Maximum Node Spacing window then a new node will be inserted mid-way between these nodes. If the distance between the newly inserted node and the nodes either side still exceed the maximum node spacing then another node is inserted mid-way between the nodes. This process will continue until the distance between all nodes in the object is equal to or falls below the maximum node spacing.

To view the nodes once they have been created make sure the table it editable in the map window. Select a single object and use the Reshape button to view all the nodes in a table.

Note To create point objects from nodes within a map object use the Discover>Data Utilities>Extract Nodes tool. This is particularly useful for creating points from nodes inserted along line at regular intervals.


Changing Line Direction

Discover>Object Editing>Change Line Direction

Use this feature to ensure that polyline coverage for drainage, roads etc. have a consistent line direction. This is important for providing indications of direction of flow, or when creating worm diagrams for stream sampling data.

Select the polylines or regions to change direction. Select Change Direction from the Object Editing menu.

Creating Donut Polygons

Discover>Object Editing>Donut Polygons

Use the Donut Polygons function when a polygon map contains overlapping or in-lying polygons to cut-out or excise the smaller polygons from the larger ones.

Geological maps commonly show geological units occurring within or cutting across other geological units. For example, a dolerite dyke may cut across a sandstone unit or a conglomerate may lie within a greywacke unit. In MapInfo, you must be careful that this situation is handled correctly.

Imagine you digitize two geological boundaries into a layer, one within the other. The outer one is a Cainozoic unit, the inner one a granite intrusion. If you use the MapInfo Select tool to click on the Cainozoic unit, the selected region includes the area of the granite. This inner boundary needs to be cut out or excised from the outer boundary, so that the outer boundary appears like a donut.

When this is achieved and you ask MapInfo to report on all mineral occurrences within the Cainozoic unit, it correctly ignores those occurrences that fall within the in-lying granite polygon.

Reverse the direction of selected polylines or regions.


Discover allows you to cut out all overlapping polygons for an entire polygon table in one step. All the attributes that have previously been associated with the polygons are preserved. The cutting is performed on the basis of polygon area with smaller polygons always being excised from larger polygons.

All you need to specify are the names for the input and output files. As Discover processes the polygons, it may come across some cases that cannot be satisfactorily cut out. In this case a message is written to the file DONUT.ERR in the temporary files folder.

The processing may take quite some time to complete. The more polygons and the larger the polygons, the longer it takes to process the table. To decrease processing time, you should ensure that the table to be processed is not open in a map window (so that MapInfo does not spend extra time redrawing the window each time an object is modified).

Note If the data being processed has not been accurately digitized (for example, polygons overlap many times along a common boundary) then Discover may take a lot longer than expected as it attempts to ensure that no overlapping polygons remain in the map.


Clipping

Discover>Object Editing>Clip to Polygon

Discard data that lie outside a selected region, clipping the retained data at the region boundary. The clipped data may be written to new tables in the same folder or to a new folder.

You can use Clip to Polygon to create subsets of data from larger data sets. For example, you may wish to keep all data for a particular tenement in one folder. You can display all your data in a map window and select the required tenement boundary. Discover can then discard all data that doesn’t lie within the tenement. This allows you to easily distribute the data for just that tenement or produce maps showing only the relevant data. This can also be a great way of producing vector data subsets for relinquishment reports.

Whilst this can be fairly straightforward to do in MapInfo with one layer, it is very time consuming to do for multi-layered data sets. Discover works with an unlimited number of layers, allowing unsupervised clipping to be performed with just a few mouse clicks.

Polygon Clipping Options

Choose between clipping outside and clipping inside the selected polygon. Clipping outside removes all data lying outside the polygon, whilst clipping inside removes data lying within the polygon. Discover uses a combination of techniques to discard the data that is to be clipped.

For clipping outside, objects that lie totally outside the selected polygon are discarded. Similarly, objects that lie totally within the polygon are kept without editing. For lines, polylines and regions that lie across the boundary of the selected polygon, these objects are simply split. Other objects such as arcs, rectangles and ellipses are converted to polylines or regions and then split. For text objects, if the centroid of the text lies within the selected polygon, the text is retained, otherwise it is discarded (text objects cannot be split).

Note Clip to Polygon does not clip objects contained in the Cosmetic layer.

Note To clip Raster Imagery, use the Images>Clip Image tool. To clip Gridded Surfaces, use the Surfaces>Grid Utilities>Clip tool.


Polygon Clipping Data Tables

Discover lists all of the tables displayed in the map window that can be clipped. Raster images and thematic layers are ignored. If you wish to leave a table out of the clipping operation uncheck the checkbox to the right of the table name. The table name is greyed out to show that it is not to be clipped.

By default, Discover suggests that you do not edit your existing data, but copy the clipped data to new tables with similar names to the original tables. The clipped tables contain the original file name followed by a “_CLIP” or user-defined suffix.

Clip Layer Dialog showing clipping options and default clip suffix

When you click OK, Discover asks which folder to save the new tables to (if operating on a copy of the data). When the clipping operation is carried out, all tables are packed and saved, and removed from the map window. Any thematic layers in the original map window are discarded, so you should ensure that you have a workspace saved prior to re-running the Clip to Polygon command. You cannot undo a Clip to Polygon operation, and for this reason we recommend that you operate on a copy of the original data.

Splitting Multiple Polylines and Polygons

Discover>Object Editing>Split MultiPolys

There is no straightforward way in MapInfo of disaggregating a map object comprised of a number of polylines or polygons. Such objects are created using the MapInfo Objects>Combine menu option and can be split one at a time using the Objects>Split menu option together with a suitable splitting object.

Easily split multiple polyline and multiple polygon (region) objects into a corresponding number of separate map objects. Attributes from the original multiple object are retained in the resulting single objects.


To disaggregate a multiple polyline or polygon object, select all of the component map objects and choose Object Editing>Split MultiPolys. Any other selected objects that are not polylines or regions remain unaffected. The attributes from the original multiple polyline or polygon object are transferred as attributes to the newly-created separate polyline or polygon map objects.

A region with a hole is stored by MapInfo as two polygons. If you split a region such as this, then there is a polygon in place of the hole and another polygon covering the entire area of the original region plus the hole.

Using Polyline and Polygon Attributes

• Assigning Values to and from Polygons

• Assigning Values to Polygons from a Grid

• Calculating Line Orientation

• Extracting Nodes

• Calculating Area Change

Assigning Values to and from Polygons

Discover>Data Utilities>Assign Values

Use Discover to assign aggregate values using data attributes from map objects in one table to the containing polygon map objects in another table. For example, assign the median Au rock-chip sample value to the surrounding geological unit polygon from which a number of rock chip samples are taken.

Alternatively, use the Assign Values function to assign polygon data attributes in one table to contained map objects in another table. For example, assign the underlying mapped geological unit to all soil samples that are taken within this boundary.

Specify the Assignment relationship between the two tables. Choose the From Table and from column via the pull-down lists for the table that contains the value to assign. Choose the To Table and to column via the pull-down lists for the table that is to be updated with the assigned value. The method of operation is chosen in the Assign Direction control. Choose to assign from Contents to Container or from Container to Contents.


Assigning values from one table column to another with a selectable operator

The data to be aggregated or assigned does need to be in the selected data column but may be specified using an Expression similar to that used in various other MapInfo functions. Select Expression in from column or to column pull-down and enter in the correct syntax.

The chosen Assign Direction method will influence the Assignment operators available for selection.

Contents to Container

If the Contents to Container assign direction is selected a number of aggregate Assignment operators are available:

• Frequency

• Minimum

• Maximum

• Sum

• Mean

• Median

• Weighted Mean (mean weighted by the value of another column in the contents table)

• Standard Deviation

• Mean weighted by area (multiplied by a scale factor from 106 to 10-6)


The Contents to Container method can be used calculate the mean assay value of stream sediment samples weighted by catchment area or to construct a simple density map by assigning the number of mineralised samples within grid squares to the grid squares.

Container to Contents

Use the Container to Contents method to assign a data value such as catchment ID or lithology from polygons to the points or map objects that lie within the polygons. Discover assigns the individual value from each polygon to the contained objects. The individual value may be created from an Expression.

Assigning Values to Polygons from a Grid

See Assigning Values from a Grid to Map Objects.

Calculating Line Orientation

Discover>Data Utilities>Line Orientation

Store the orientation of selected lines as an attribute.

This feature is useful when analysing tables containing linear map objects such as faults, fold axes or creeks where no directional attributes exist. Use the Discover Line Orientation utility to easily obtain the orientation of a line or polyline and add the direction as an attribute into a selected column in the table.

Line Orientation dialog


Select the column to add the line orientation attribute from the Add Line Orientation to Column pull-down list. The direction is generally the average orientation for each polyline although options to record the orientation of the First segment or Last segment are available. In the Use Angles in Range choose the desired angle range from 0-360, 0-180 or 180-360 for recording the line orientation attribute. Select a Round By interval from the pull-down list.

Click OK to update the table with the line orientation data.

Use the Discover>Object Editing>Change Line Direction utility to reverse the direction of lines if necessary.

Extracting Nodes

Discover>Data Utilities>Extract Nodes

Nodes or line segments from a polyline or polygon can be extracted using the Discover Extract Nodes utility. For Example, extract nodes from contour lines and re-process the 3 dimensional point data to create a new interpolation grid. Extracted node coordinates from polylines or polygons are added to a new table as attributes with the option to display the node point objects in a map window. Extracted line segments are automatically displayed in a map window.

Select the polyline or polygons to use in the extraction and choose the Extract Nodes menu option. The Node Extraction dialog is displayed:

Node Extraction dialog.


Select the Extraction Type. If the Extract Points option is selected the Extraction Options will become available. Check the Create point objects box to display the extracted nodes in a map window and select an appropriate symbol style. The extracted node points are created in the same projection as the base polyline or polygon table. All columns in the base table will be added to the extracted node table but only the column selected as the Get attribute from column will display attribute data.

For very detailed linework it may not be necessary to extract every node as a point. In this case enter a number greater than 1 in the Extract every n nodes control. For example, Extract very 4 nodes will extract every 4th node in the selected objects. Enter a file name and location to store the extracted nodes.

Calculating Area Change

Discover>Data Utilities>Compute Area Change

The Discover Compute Area Change utility provides an efficient method to quantify and map changes in area or linear features between successive layers of data. For example, the Area Change comparator can be used to examine polygon changes between two map layers representing data from different time periods.

The area change comparison is based on the polygon attributes contained in a column specified by the user. This column may contain data such as vegetation type, habitat ID, soil class, erosion level, etc. Discover groups all the polygons in a table by this attribute and identifies differences between polygons of the same code in the different map layers. The area change calculator is primarily designed for polygon data; however it can also report differences in overall length of linear data and the number of point objects between two tables. Select Compute Area Change from the Data Utilities menu option to display the Compute Area Change dialog:

Note Nodes cannot be extracted from map objects in the Cosmetic layer.


Area Change dialog set-up to perform a detailed comparison between the two areas. Regions that have changed in size and shape will be shown in different patterns as areas gained and lost

Select the two tables to compare from the Table1 and Table2 pull-down lists. Select the polygon (line or point) attribute column to compare. Discover automatically assigns a default report table and map table name and destination. Use the Report Table and Map Table buttons to assign new names and locations if desired. A tab-delimited text file export option is also available: the text file is saved to the same directory as the Report Table, with the same name.

The report produced by Discover lists for each unique attributed code:

• the old and new areas

• the area change (actual and percentage)

• the old and new polygon perimeter

• the perimeter change (actual and percentage)

• the number of old vs. new polygons/areas

If the Show codes lost to/gained from box is checked, a Change field will additionally report on which attribute codes have either lost or gained in area.


In order for Discover to display the area change information visibly in a map, the Lost area style and Gained area style should be set. Discover can use the original colour of the polygons and apply a different pattern to show whether area has been lost or gained. Alternatively, Discover can retain the original pattern of the polygons and use a different colour to show area change. With either of these two options, the display of the changed area retains some of the display attributes of the original data. The user can also specify a new style to show all gained areas and a different style to show all lost areas. In this case, all lost areas are displayed in the same style, regardless of their map code.

Map window opened on completion of Area Change computation. Note area gained or area lost displayed in different patterns

Conditioning and Converting Linelwork into Polygons

Discover>Object Editing>PolyBuilder

The Discover PolyBuilder utility is designed to simplify the conversion of digitised linework (representing regions) into polygon vector objects. A common use is the digitisation of lithological units or land use areas from a scanned and georeferenced image (e.g. open file report) as series of lines or polylines. This linework dataset is then converted into an attributed dataset of polygon regions.


Map window on left showing flagged errors including duplicate lines, intersections and free end points. Map window on right showing completed polygons.

The PolyBuilder process uses the following functionality:

1. Check LineworkIn order to create polygons from linework datasets, the linework must be free of any lines which are duplicated, extend past or fall short of other lines. This tool ‘flags’ all such errors.

2. Correct LineworkThe linework dataset is then “cleaned”, removing all identified errors. All the overlapping linework is broken down into individual line segments. This tool can be run in either an automated and manual mode.

3. Create PolygonsAll cleaned line segments that enclose an area are joined together, creating polygons.

4. Attribute Polygons with TextOnce polygons have been created, they can be attributed (as a browser attribute) using text located within the polygons.

The Polybuilder utility also provides the following tools:


• Digitize LineworkThe digitzing utility allows source linework to be created from scratch. This tool enables the storage of feature linestyles to aid in consistent data capture. It also allows features to be added as attributes during the linework creation process.

• Additional Linework UtilitiesIn addition to the streamlined polybuilder process tools (above), additional tools to break, join and filter linework datasets can be run separately.

The PolyBuilder utility is recommended for use with data captured in a projected coordinate system (e.g. UTM, MGA, etc), not geographic (latitude/longitude) data. It is also recommended that the map window Distance units match the coordinate units, e.g. metres.

In each of the PolyBuilder processes the original files are always maintained. Any new files created contain the results of each procedure/tool plus any unprocessed data from the original file, leaving the original files intact. In this way the PolyBuilder output files can be checked and re-processed if necessary before saving the final linework file. The projection of the original file is also retained in any new files created.

PolyBuilder Dialog

Standard PolyBuilder dialog

Note Polybuilder cannot edit read only tables, and these cannot be selected. Save a native copy first using File>Save Copy As. Polybuilder will also automatically save any changes on an unsaved input table.

The PolyBuilder dialog contains pull-down menu options combined with a series of toolbar buttons which provide access to the various PolyBuilder functions. The dialog can be closed using the Close button in the top right-hand corner of the dialog or selecting Exit from the Edit menu.


Expanded PolyBuilder dialog showing Check Linework results

Linework Layer

The Linework pull-down list displays the current layers in the active map window. Select the linework layer to check and clean or the polygonized layer to attribute from this pull-down list.

Text Layer

The Text pull-down list displays the current layers in the active map window. The text layer which contains annotations to be used to attribute polygons is selected from this pull-down list.

Menus

The PolyBuilder dialog is comprised of two pull-down menus:

• Edit – Contains options to set various Preferences for detecting and cleaning linework along with the ability to Import and Export digitizing line styles.

• Help – Provides access to On-Line Help and PolyBuilder About dialog.

The dialog can be expanded using the Arrow button. It is necessary for the dialog to be expanded in order to view the results after cleaning data or to view available digitizing styles.


PolyBuilder Toolbar

The fixed PolyBuilder Toolbar contains the following buttons:

Digitize LineworkSelect a line style and manually digitize linework into a MapInfo window. Linestyles can be selected from predefined styles and feature names can be automatically added to an column in the table.

Check LineworkCheck digitized linework for free endpoints, overlaps and duplicates according to options set in the Preferences dialog. Errors are flagged in the map window and reported in the PolyBuilder dialog.

Extend and BreakThis process extends all lines which have free endpoints by the distance specified in the Preferences dialog. All intersecting linework is then broken into segments and overlaps, overshoots and duplicates removed.

Create PolygonsJoin together all adjacent line segments which form continuous enclosed boundaries to create a series of polygon objects.

Attribute PolygonsUse labels from a separate text or annotation table to add attribute data to the newly created polygon map objects.

Linework ToolsAdditional line tools that can be run as separate processes to Break all existing linework at intersections, Join adjacent linework together or Filter to simplify complex linework and reduce file size and processing time.

Previous Error FlagMove to the previous error flag in the map window to manually find and fix linework errors.

Next Error FlagMove to the next error flag in the map window to manually find and fix linework errors.


Preferences

Edit>Preferences

The PolyBuilder Preferences dialog contains various options which can be customized while working within the PolyBuilder utility.

Fix LineworkUsed in conjunction with the View Previous/Next error flags this tool enables linework errors to be fixed manually by extending lines.

Delete Error FlagUsed to delete all error flags or only those of a selected error flag type in the map window. Also contains option to delete error flags when moving through and fixing them using the Previous/Next Error Flag buttons.


Linework

The Linework controls are primarily used when running the Check Linework process to initially detect problems in the linework dataset.

• Endpoints – Check to flag all free endpoints (lines which do not intersect with another line)

• Overlaps – Check to flag all lines which overlap each other

• Duplicates – Check to flag all instances of multiple lines at the same location

• Gaps smaller than – Check and enter value to flag all free endpoints that lie within the specified distance of another line.

• Gaps larger than – Check and enter value to flag all free endpoints which lie outside the specified distance from another line.

When Gaps Smaller than or Gaps Greater than is selected for use, the options to manually select Overlaps and Duplicates is greyed out. Therefore when checking linework using these options, only Free End Points are flagged.


• Extend Distance – Value used in the Extend and Break Linework process to extend free endpoints the specified Extend Distance. End points which are extended and make contact with another line will be broken whereas end points which do not make contact with another line will be restored to their pre-extension distance once the process is complete.

• Close – Check to convert closed polylines to polygons when using the Join Linework utility.

• Honour Symbology – Check to only break or join lines which contain identical symbology (line styles) when using the Break Linework or Join Linework utilities.

• Filter Distance – Tolerance distance used to remove vertices from complex linework when using the Filter Linework utility.

Polygons

• Place Polygon Centroids: - Check to create a new file containing polygon centroids when using the Create Polygons utility.

Field Information

• Allow Duplicate IDs: - Check to enable an attribute to be assigned to multiple polygons when using the Attribute Polygons with Text utility.

Digitize Linework

The PolyBuilder utility enables linework to be screen digitized directly into a MapInfo table. Usually a linework table is created by digitizing (drawing a map object on the screen) which traces an underlying linear feature on a scanned map. To digitize using the PolyBuilder digitizing utility:

1. Select the layer to digitize the new linework into from the Linework Layer pull-down list. The new linework table must already be created in MapInfo and added to the active map window in order for it to be available for selection in this list. The table must contain a Character column to contain the digitized feature name. The Digitize Linework button will not be active if this column is not present.

Note The units used in the Gaps smaller than, Gaps larger than and Extend Distance are taken from the current map window distance units. To change the units click on the map window, select Map>Options from the MapInfo menu bar change the Distance Units in the displayed dialog.


Linework Styles

Before digitizing linework using the PolyBuilder utility a linework Style must be selected. A Style is a predefined line style, colour and thickness combination which represents a particular linear feature. e.g. Drainage, creeks, roads, faults, folds, etc. These Styles can be saved and re-used in the future when digitizing future linework to ensure consistent data displays between similar linear features.

The Style name can also be added into a designated field in the digitizing table as attribute information. For example, all lines digitized using a linework style called River will have “River” added as an attribute into a specified column in the table.

3. When the Digitize Linework button is selected in Step 2 the Field pull-down list becomes available. Choose a field (columns) from the linework layer to store the name of the linework Style used for each digitized line as an attribute.

4. To select linework Styles from a previously saved list select the Import Styles option from the Edit menu. The saved Styles are listed in the window at the bottom of the PolyBuilder dialog. To create a new linework Style go to Step 5.

5. To add a linework Style to an existing list or to create a new Styles list right-mouse click in the window at the bottom of the PolyBuilder dialog and select Add from the pop-up menu.

2. Select the Digitize Linework button from the PolyBuilder toolbar.

Note Linework Styles can only be stored in fields which are of a Character data type. Make sure that the field selected is wide enough to store the Style name otherwise it will be truncated without warning. Use the MapInfo Table> Maintenance>Table Structure utility to add or modify fields in the linework table if necessary.


6. In the Digitizing Style dialog enter a name for the new Style.

7. Click on the Line Style button. Choose a line style, colour and thickness for this Style. Click OK to add the new Style to the PolyBuilder dialog window. Repeat steps 4 to 6 to add more linework Styles to this list.


8. To edit a linework Style highlight it in the list and then right-mouse click and select Edit from the pop-up menu. Alternatively, to delete a linework Style select Remove from the pop-up menu.

9. To save a new or edited Styles list, select the Export Styles option from the Edit menu and enter a file name and location. Linework Styles are stored in an ASCII file with a .DAT extension. To reuse saved linework Styles see Step 4.

Digitizing

10. To digitize linework highlight the appropriate Style from the Styles list in the window at the bottom of the PolyBuilder dialog. PolyBuilder should automatically make the selected layer editable.

11. Choose the Polyline drawing button from the Drawing toolbar and digitize the line in the map window.


Check Linework

• Free Endpoints – Lines which do not intersect with any other lines

• Overlaps – Lines which overlap each other

• Duplicates – Two or more lines at the same location

The reason this process is required is that if free endpoint, overlapping or duplicate lines remain in a linework table which is then converted into polygons or used as a linear network, the resulting dataset may be incomplete. It is therefore strongly recommended that all linework is checked and cleaned prior to being polygonized or joined in a linear network.

Check Linework is usually the first process to be run on line data when it is going to be used for polygon creation or to create a linear network. The purpose of this procedure is to check all the linework in a table and flag all instances of the following:


The Check Linework utility will only process lines and polyline strings. Other elements such as arcs will be ignored and multi-segment elements will report an error. The Check Linework process will therefore flag a line as a free endpoint where it joins an arc element. It is recommended that all multi-segment linework is disaggregated into individual elements and to avoid using arc elements before running the Check Linework procedure.

The Check Linework utility will also return an overlap error when a line string or shape contains multiple vertices that are the same. This problem can be fixed by removing the offending vertex.

1. Open the linework dataset into a map window.

2. In the PolyBuilder dialog, select the Linework Layer from the pull-down list.

4. To see the Check Linework results, expand the PolyBuilder dialog.

3. Click on the Check Linework button on the PolyBuilder toolbar.


Error Flags

After the Check Linework process is run all endpoints, overlaps and duplicates are marked using a different type of flag in order for them to be easily distinguished in the map window. The PolyBuilder window displays the total number of line segments (elements) in the table, the number of flags created for Free Endpoints, Overlaps and Duplicates and the time it took to process the table.

These error flags are placed in a temporary file called PolyBuilderErrors and is added to the original linework map window. This error table is continually overwritten during the various processes in the PolyBuilder utility and is permanently deleted upon exiting MapInfo.

In the map window Free Endpoints are denoted by a circle, Overlaps where two lines intersect are marked by a square and Duplicates are indicated by a thick red line defining the extent of the duplication.

Linework Checking Error Flags

To fix the flagged errors follow the steps outlined in Correct Linework. When the errors are corrected rerun the Check Linework process to ensure that all the linework problems are fixed. It is not unusual for the Check Linework process to be run multiple times before a dataset is free from errors.


When checking linework in a linear dataset e.g. a road or drainage network, free end points may be legitimate and not just lines which have fallen short of intersecting with other lines. The user may first check the dataset for Overlaps and Duplicates before controlling the method of checking for free end points. This is done by modifying the Edit>Preferences settings to only flag those errors with a gap smaller than or larger than a calculated distance.

For example, If the Gaps Smaller than option in the Edit>Preferences dialog is selected and the desired distance is set to 10m, PolyBuilder will only flag the free end points with a gap smaller than 10m from another line. In a road network where roads often stop short of another road, selection of the correct distance will result in error flags being created only for those roads which are intended to intersect another road. See Preferences for more information on setting these Check Linework options.

Correct Linework

To correct lines which have been flagged as being erroneous in the Check Linework utility there are two processes available in PolyBuilder:

• Extend and Break Linework – An automatic process which can extend linework to intersect other lines and break overlapping linework into individual elements.

• Fix Linework – Manual process which enables flagged errors to be stepped through and corrected one by one. Generally used to fix any remaining errors after the Extend and Break Linework process has been run.

Extend and Break Linework

During the Extend and Break Linework process duplicate line segments are removed, undershoots are extended, overshoots are removed with all intersecting linework broken down into separate line strings ready for use in the Create Polygons utility.

Note The units used in the Gaps smaller than, Gaps larger than and Extend Distance are taken from the current map window distance units. To change the units click on the map window, select Map>Options from the MapInfo menu bar change the Distance Units in the displayed dialog.

Extend and Break Linework combines several of the core PolyBuilder processes to fix linework errors that have been flagged as End Points, Overlaps and Duplicates in the Check Linework utility.


The corrected linework data file is named using the original linework file with a “_clean” extension. i.e. if the original file is Linework.TAB, the file containing the corrected linework will be named Linework_clean.TAB. The new file is created using the same projection as the original linework table and is added to the map window. The original linework table is removed from the map window and closed and the cleaned table is added as the Linework Layer into the PolyBuilder dialog.

Undershoots and Overshoots

An Undershoot error occurs where a line does not quite reach the point intended on a nearby line whereas an Overshoot (or dangle) is the result of a line extending too far past a line when it should be terminated.

To correct undershoot and overshoot errors the Extend and Break utility extends all Free Endpoint lines by a user-defined distance and then a linework break process is run to cut all intersecting linework. The aim of this process is to leave the clean linework free of undershoots with only a possible small overshoot as a result of the initial extension distance being slightly too large.

After all the Free Endpoint lines are extended all lines now have a length which is less than the Extend Distance are deleted and all Free Endpoint lines that are longer than this distance will be reduced by the Extend Distance. This should result in the removal of any small overshoots created in the extend process and the return of all lines that did not overlap any other linework to their original length. See Extend Distance for more information.

Finally, the process which deletes lines with a free endpoint of length less than the original user defined distance is repeated to account for any overshoots in the original data. Upon completion of this procedure all undershoots and overshoots should have been removed and the data should be free of overlaps and duplicates.


Extend and Break Process

Re-run the Check Linework utility as the Extend and Break Linework process does not fix all errors and some manual correction is generally required. See Fix Linework for more information. One of the most common errors is where two parallel or near-parallel free end point lines remain and must be corrected manually as they will not join when extended by the nominated distance.

Extend Distance

The Extend Distance option is set in the Preferences dialog and is used to automatically control the extend search distance. The Extend Distance needs to be chosen carefully and with a good understanding of the data. The distance should be large enough to fix as many undershoots/overshoots as possible but not so large as to cause a lot of unwanted intersections. Any errors that remain will be identified and need to be corrected manually using the procedure outlined in Fix Linework.

Fix Linework

The Fix Linework correction utility is used in conjunction with the View Previous/Next Error Flags buttons and the Delete Error Flag option. It has been developed to assist in the correction of errors flagged during the Check Linework process and not corrected using the automated Extend and Break Linework process.


Error flags may be sequentially viewed, corrected and deleted or optionally disregarded and deleted. Various combinations of errors will require the application of different logic to achieve a satisfactory solution.

View Previous/Next Error Flag

The map window will centre the error flag in the view and make it available for correction. As each error is corrected, the user can proceed to the next error flag by selecting View Next Error Flag. It is also possible to view the previous error flag by selecting View Previous Error Flag.

Delete Error Flag

These options can be used to delete the currently selected error flag, any particular type of error flag or all error flags. The flag deletion type is selected from the Delete Error Flag menu.

Delete Error Flag list

To delete all error flags of a particular type e.g. intersections or endpoints select the appropriate option from the Delete Error Flag list.

After running the Check Linework tool, any errors not automatically fixed will be marked with an error flag. To manually find and fix these errors, it is necessary to scroll through the dataset using the View Previous/Next Error Flag buttons.

Note It is only possible to view the previous error flag if the Automatic Error Flag Deletion option is unchecked in the Delete Error Flag menu.

To delete single or multiple error flags select them in the map window and click on the Delete Error Flag button.


The Automatic Error Flag Deletion option will automatically delete flags as they are moved through for correction using the View Next Error Flag button.

Free End Point Errors

If after running Check Linework two lines intending to finish at the same point overshoot by a small distance this will result in two free end points and an overlap as shown below.

If the Extend and Break Linework utility is run on this data the overlap error will be automatically fixed and only the free end point errors will remain.

Overlap and free end points

There are two types of Free End Point errors which are flagged:

1. Overshoot/Dangle - A line overlaps the line it was intended to finish and an overshoot or dangle results. Dangles are lines that do not contribute to the boundary of a polygon and should be removed.


Free End Point Dangle - Before and after deleting the dangle

In the example above the Free End Point error flag is placed on the line segment which is the dangle. This short line segment was created after going through the PolyBuilder processes (Check Linework and Extend and Break Linework). The original line has been broken, correcting the overlap error and the Free End Point error flag placed at the end of the dangle.

To correct this dangle, the line segment should simply be deleted using the keyboard Delete button. Click on View Next Error Flag to move to the next error flag.

2. Undershoot - A line falls short of its intended finish position and a gap is present. Gaps within linework used to create polygons restrict the creation of areas and must be repaired.



Free End Point Undershoot - Before and after extending the undershoot

Click on View Next Error Flag to move to the next error flag.

Overlap

The error flag and overlapping linework are highlighted. This error is automatically fixed using the Extend and Break Linework utility and should not require manual intervention.

Duplicates

The error flag and the elements that contain the duplicate section are highlighted. This error is automatically fixed using the Extend and Break Linework utility and should not require manual intervention.

In the example above the Free End Point error flag is placed on the line which requires extending to remove the gap. Using the MapInfo Selection tool from the Main Toolbar, highlight the line to intersect. Then select the Fix Linework tool from the PolyBuilder toolbar. The line will automatically be extended to the selected line and close the gap. The selected line is also automatically broken at the point where the lines intersect.



Create Polygons

1. In the PolyBuilder dialog select the cleaned linework from the Linework Layer pull-down list.

3. To see the Create Polygons results expand the PolyBuilder dialog.

Create Polygons is a procedure that joins line segments which enclose an area and then converts the closed linework strings to a region or polygon object. The new polygon data file is named using the clean linework file with a “_polygon” extension. i.e. if the clean file is Linework_clean.TAB, the file containing the polygons will be named Linework_clean_polygons.TAB. The new file is created using the same projection as the clean linework table and is added to the map window.

2. Click on the Create Polygons button on the PolyBuilder toolbar.


The polygon table generated by PolyBuilder has a standard structure:

• POLY_ID - Character (1)

• AREA - Float

• CENT_X - Float

• CENT_Y - Float


The POLY_ID field for each polygon is populated with "*" until it is attributed using the Attribute Polygons with Text utility. The AREA field is populated with the area of the polygon and the CENT_X and CENT_Y are populated with the X and Y coordinates of the centroid of the polygon.

To create an additional table that contains the centroids of each newly created polygon make sure that the Place Polygon Centroids option is checked in the Preferences dialog.

Polygon Errors

When creating polygons it is possible to get a polygon loop error. This error occurs when the line loops back on itself while tracing out a polygon. The error is flagged by a red triangle symbol and it may be difficult to determine the cause of the loop.

Generally a polygon loop error may indicate unnecessary or missing linework. For example, in the figure below a possible line is missing which is need to divide the larger polygon into two regions a and b. PolyBuilder will create polygons irrespective of polygon loop errors but it is important to later locate the cause of these errors and either delete unnecessary linework or add linework until all the errors have been corrected.

Another error that may be encountered in this process is the centroid error which will occur if a polygon is too small to contain the calculated centroid. It is possible to construct shapes that are so small that no possible centroid point falls inside them. This normally indicates extreme circumstances such as 'sliver' polygons, which are usually small and safe to ignore. Later processing is not normally inhibited.


Donut Polygons

Where a polygon is created that falls entirely within another polygon it will be excised (or donuted) from the larger polygon.

Attribute Polygons with Text

Linework with text annotations in separate layer

Attribute Polygons with Text enables polygons created from a linework file to be assigned an attribute from a piece of text which is located within the enclosed polygon object. The text is added as an attribute in the browser for each polygon object into a column named POLY_ID.


The location of the text used to attribute a polygon is always the bottom left hand corner irrespective of its justification. The text can be any size and length provided that the bottom-left corner of the text label is located within the designated polygon. When the text is added to the polygon table the POLY_ID column will automatically be adjusted to the width of the longest text string in the text file. To attribute polygons using text:

1. Make sure the cleaned linework dataset is open in a map window.

2. Open the table that contains the text data into the same map window.

3. In the PolyBuilder dialog select the cleaned linework from the Linework Layer pull-down list.

4. Select the text layer from the Text Layer pull-down list.

6. To see the Attribute Polygons with Text results expand the PolyBuilder dialog.

After running the Attribute Polygons with Text process a number of possible error conditions can result which are displayed in the PolyBuilderErrors layer which added to the map window.

5. Click on the Attribute Polygons with Text button on the PolyBuilder toolbar.


• No Node – Polygon does not contain any text strings and a red hollow diamond shaped symbol is placed at the centroid of each polygon for identification in the map window.

• Multiple Node – Polygon contains more than one text string. A red filled diamond shaped symbol is placed at the centroid of each polygon for identification in the map window.

• Node Outside – Text strings which do not fall within a polygon. A red circle is placed at the text centroid for identification in the map window.

All polygons that are properly identified will have their POLY_ID field updated in the polygon table. Any polygons which fall into any of the above error categories will have an attribute entry of "*****" in the polygon table.

If there are polygons which are to be attributed with the same text make sure that the Allow Duplicate IDs option is checked in the Preferences dialog. If this option is unchecked and there are multiple instances of the same attribute in the text table a large number of entries and symbols are added to the PolyBuilderErrors table and a message such as "114 duplicate text id's" will be displayed. Check this option in the Preferences dialog and rerun the process to correct.

Additional Linework Utilities

The PolyBuilder module contains additional linework utilities to aid in the creation of linear networks. These include:

• Break Linework – Break overlapping linework into individual segments and remove duplicates

• Join Linework – Join adjacent line segments together to create a series of polylines

• Filter Linework – Reduce the number of vertices in polylines to simplify complex linework and reduce file size

All of these processes create a new file containing the results of each procedure plus any unprocessed data from the initial file, leaving the original files complete. This enables the output files to be checked, corrected and re-processed if it is found to be unsatisfactory before finally saving the new file to the original file name.


Break Linework

Overlapping linework Line segments after breaking

Unlike Extend and Break Linework, the original file is not closed and the new file is added to the current mapper window. After the Break Linework is completed the Check Linework process is run on the new linework file. This should produce no errors other than free endpoints, if applicable.

The Break Linework utility can only be used with line and polyline data and does not support arc or multi-segment elements. Any arc or multi-segment elements will be copied to the output file so that this file will look the same as the original linework table except that all the linework errors, other than free endpoints, will be removed.

If the Honour Symbology option is checked in the Preferences dialog only lines with the same symbology (line style, colour and thickness) will be broken. If this option is unchecked then overlapping lines with different symbology will be broken. All linework must be in the same file for it to be broken.

Break Linework takes linework from the selected linework file and breaks it into individual line segments where an overlap occurs. Any duplicated lines are removed and the resulting lines are saved to a new file. The new broken data file is named using the original linework file with a “_break” extension. i.e. if the original file is Linework.TAB, the file containing the broken linework will be named Linework_break.TAB. The new file is created using the same projection as the original linework table.


Join Linework

Unjoined linework Lines after joining

The Join Linework utility can only be used with line and polyline data and does not support arc or multi-segment elements. Any arc or multi-segment elements will be copied to the output file so that this file will look the same as the original linework table except that all the linework errors, other than free endpoints, will be removed.

All the joined linework will be open even if the strings have a common start and end vertice. To convert closed polylines to polygons check the Close option in the Preferences dialog.

If the Honour Symbology option is checked in the Preferences dialog only lines with the same symbology (line style, colour and thickness) will be joined. If this option is unchecked then adjacent lines with different symbology will be joined. All linework must be in the same file for it to be joined.

Join Linework takes linework from the selected linework file and joins it into continuous line strings where elements are adjacent. Joining lines can significantly reduce the number of elements in a file and result in a reduction in file size.

The new joined data file is named using the original linework file with a “_join” extension. i.e. if the original file is Linework.TAB, the file containing the joined linework will be named Linework_join.TAB. The new file is created using the same projection as the original linework table. The Join Linework process does not introduce any new linework errors.


Filter Linework

Original Linework and filtered result

Filtered linework is guaranteed not to deviate from the original linework file by more than the tolerance set and the start and end points will remain the same. If all the vertices are less than the tolerance distance from the first point the element is removed. If a tolerance of 0.0 is chosen only duplicate vertices i.e. consecutive vertices with the same coordinate value and co-linear points (points lying on a line) are removed.

After filtering linework the output file may consist of many elements each with only a small number of vertices. It is recommended that the Join Linework utility is run to join all adjacent linework together.

Colouring Map Objects

• Colour Map Objects from Look-up Tables

• Saving and Applying Thematic Map Settings

• Colour Map Objects by RGB Values

Filter Linework is used to simplify complex linework and reduce file size and processing time. Linework is filtered by removing vertices that are within the tolerance or Filter Distance which is set in the Preferences dialog. The new filtered data file is named using the original linework file with a “_filter” extension. i.e. if the original file is Linework.TAB, the file containing the joined linework will be named Linework_filter.TAB. The new file is created using the same projection as the original linework table.


Colour Map Objects from Look-up Tables

• Creating Colour Look-up Tables

• Create a Colour Table from an Existing Map

• Create a Colour Table from a Thematic Map

• Edit a Colour Table

• Apply a Colour Map to Map Objects

• Create a Legend from a Colour Table

• Export a Colour Map to Discover Mobile

Creating Colour Look-up Tables

The Discover ColourMap utility adds a separate menu to the MapInfo menu bar and contains the following functionality:

• Create a standard colour look-up table for polygon, polyline or point data maps.

• Automatically assign colours and patterns to individual polygons or polylines or symbol colour, size and type to points in a MapInfo table.

• Map objects may be permanently coloured or displayed using a thematic shade.

• Import colour look-up table for use with the Discover Drillholes module

• Export colour look-up table for use with Encom Discover Mobile

The Discover ColourMap utility can be used to build a standard table of map object fill, linestyle or symbol colours and styles and then apply these standards to each map object in a map window layer. Each map object in the layer must have an attribute code which matches an attribute code in the ColourMap table. For example, the code may be a standard abbreviation for a specific rock unit (i.e. "Czc" for Cainozoic, etc and must be the same in both map and look-up table.

MapInfo uses the 24-bit RGB method of colour definition, whereby the red, green and blue components of a colour are each specified in the range 0 - 255 to give a maximum of 16.7 million colours. When colours are assigned during the creation of the ColourMap look-up table, the red, green and blue components are automatically added to the table as attributes.


It might be useful to use a printer colour chart when assigning colours to map codes.

To select or create a colour look-up table:

Select the ColourMap>Setup menu item to display the Colour Maps dialog:

Colour Map maintenance and creation dialog

There are four Colour Table Options to choose from:

• Select colour table - Choose an existing colour table to apply to a new set of map objects.

• Create empty colour table - Create a colour look-up table manually by entering in RGB values for codes from an external source.

• Create colour table from existing map - Create a new colour look-up table using map styles and codes from an existing table. The existing table can be non-mappable such as a drillhole lithology table. See Create a Colour Table from an Existing Map.

• Create colour table from thematic map - Use the colours and styles from a thematic map to create a colour look-up table. See Create a Colour Table from a Thematic Map.

Once a colour table has been chosen the Edit Colour Table and Apply Colour Map menu items are enabled.

In order to colour a map or add colours as a thematic layer to the map, choose the appropriate Colour Table Option. Discover is able to colour region objects, polyline objects, point objects and text objects using ColourMap. Examples of using ColourMap look-up table with point data could be to colour RAB drillhole collars with the bottom of drillhole lithology or soil samples by their surrounding geology type.


Create a Colour Table from an Existing Map

ColourMap>Setup

1. Select an existing map table to colour from the Map Table pull-down list or use the Open a Table option to open the table into a map window.

The existing map table may already contain map objects styles which can be automatically added to the look-up table or the map object styles can be selected during the creation of the colour table.

2. Select the attribute column to use in the ColourMap look-up table from the pull-down list. By default the first column in the table is selected. All unique entries in this column will be used in the creation of the colour table. These entries are added to the MapCode column in the Colour table.

It is therefore important to make sure the data in this column is clean i.e. eliminate duplicate entries of the same data due to spelling mistakes or remove multiple data entry items for the same category. To quickly display all the unique attribute entries for a column, use the Discover>Data Utilities>Select by Group menu option.

3. Click on the Save Colour Table button and browse to a directory to save the new ColourMap look-up table. Enter an appropriate file name. Click OK to exit the Colour Maps dialog.

4. In the following dialog click YES to use the existing map colours as the basis for the new ColourMap look-up table or No to manually enter the map object styles for each unique attribute value individually.

Note The attribute column in the data table to be used in the creation of the ColourMap colour look-up table must be of CHARACTER data type.


5. A new map window is opened that contains the newly created colour table. The map window contains a single column comprising a polygon, polyline or symbol map object and the unique attribute (MapCode) taken from the data table.

In the case of a polygon object the object style will be a filled rectangle. In the case of polyline objects the object style will be the line type, colour and thickness. Symbol objects are represented by their symbol type, size and colour. If the map that you are creating the colour table from has no colouring or the table is not mappable, then all of the object styles will be displayed as default symbols or polylines with polygons displaying a null fill style.

Colour Table Map

6. To add colours or edit the existing colours for the map objects, work down the list of map codes by selecting the object for each MapCode and changing the style using the standard MapInfo region, polyline or symbol style buttons. To create a custom colour in MapInfo, select the colour square at the bottom right of the colours list and then specify the RGB/HSV values.


Build Colour Table

When each MapCode has been assigned a map object style, choose the ColourMap>Build Colour Table menu option.

When the colour table is built, Discover examines each of the MapCode object styles and inserts the RGB values and any line and symbol parameters into the corresponding columns in the colour table.

Polygon information is stored in the columns Fore_Red, Fore_Green and Fore_Blue which are populated with details of the foreground colour selected. If a patterned colour is used, the pattern number is inserted into column Pattern and background RGB values into Back_Red, Back_Green and Back_Blue. A different line style can be selected for the border of each map code polygon if desired. The line style parameters are stored in columns Pen_Red, Pen_Green, Pen_Blue, Pen_Pattern along with details about Pen_Style and Pen_Thickness. Symbol style parameters are stored in Sym_Name, Sym_Size and Sym_Red, Sym_Green and Sym_Blue. Both line and symbol objects may have foreground and background colours such as when a point symbol contains a halo.

The colour table is created with extra columns such as Desc1, Desc2 and Desc3 to store additional text enabling the columns from the colour table to be used with the Discover>Map Making>Create Map Legend feature.

Colour Map browser

Create a Colour Table from a Thematic Map

Create a thematic map for the data table and make sure it is displayed in a map window. To create a ColourMap look-up up table from a thematic map, select the Colour from thematic map option. Select the base data table from the Map Table pull-down list and use the Save Colour Table button to enter a name and location for the new colour table.


Discover will automatically create the colour table and permanently colour the existing map objects according to those in the thematic map. The thematic map may be created using any type of map object (regions, lines, points etc) as long as the thematic map was created using an Individual thematic type and not a numeric thematic type such as Ranged or Graduated. The Individual thematic column must be of character data type.

As the colour table is created, the map objects are coloured at the same time. There is no need to nominate a column to use as this is defined in the Thematic Map process.

Edit a Colour Table

ColourMap>Edit Colour Table

To modify an existing ColourMap colour look-up table choose the ColourMap>Edit Colour Table menu option for easy editing of individual colour assignments. Highlight the MapCode to edit and click on the appropriate style button. When a style is modified, click on the OK button to save the change to the colour table.

Colour Table modification dialog

If there are global changes to make to the colour table, such as altering the patterns for a number of codes, this is best done with the Browser window and the select/update menu commands.


To edit the colour table without using the ColourMap>Edit Colour Table menu option it is necessary to be able to enter patterns and line styles with the correct numerical entries. Pen styles range from 1 to 77, with style 1 equivalent to no style, 2 solid etc, in accordance with the order in the MapInfo Line Style dialog. Pattern styles range between 1 and 71, with values 9-11 unavailable. Like the pen styles, pattern 1 is invisible, 2 is solid etc, in accordance with the MapInfo Region Style dialog. Symbol size and type can also be modified in accordance with the MapInfo Symbol Style dialog.

If RGB values are imported from another source and you wish to make the hatch pattern transparent, ensure that the product of Back_Red, Back_Green and Back_Blue is negative (for example, make one of them -1, and keep the others positive).

Apply a Colour Map to Map Objects

ColourMap>Apply Colour Map

Select an existing colour table from the ColourMap>Setup dialog and choose the ColourMap>Apply Colour Map menu option to apply colours and styles to map objects. Note that this action is automatically performed when the Colour from Thematic Map option is selected as described above.

Colour Map Table dialog


In the Colour Map Table dialog, select the table to colour from the Map Table pull-down list. Use the Open a Table if the table to colour is not already open. Discover can colour multiple tables at once using the Build Batch List option from the Map Table pull-down list. Choose this option and highlight the tables to colour from the available open table list.

Once the table or tables to colour are selected choose the table attribute column from the Code from Column pull-down list. This is the column in the table that matches the entries in the colour look-up table MapCode column. This column must be of character type and must be the same column in each table when there are multiple tables selected.

Discover can apply look-up table colours and styles in one of two ways:

• Create a thematic map layer using the QuickColour option

• Permanently modify the map object styles

Create Thematic Map Layer

Check the QuickColour using thematic map shading option to use the normal MapInfo Thematic Mapping functions to colour the map objects according to the look-up table colour and styles. This method of colouring is quick and provides a MapInfo thematic legend window but is limited to a maximum of 255 different codes in the colour table.

One or more colour tables representing variables such as lithology, tectonic setting, grade of metamorphism, alteration, etc can be displayed as thematic maps in the same map window. The map window can then quickly be refreshed by turning layer visibility on or off to show the appropriate variable with the MapInfo thematic map legend window displaying a key for each colour look-up table. This is much quicker than permanently colouring the map objects each time.

Permanently Colour Map Objects

Uncheck the QuickColour using thematic map shading box to display the Objects to colour and Symbol Options. The default Colour all objects option is selected.

If the selected map tables contain a mixture of map object types then options are available to apply the look-up table colours and styles to polygon, line or text objects only, leaving all other map objects with their existing graphical attributes. Point data can be coloured using look-up tables created for polylines with additional Symbol Options available to modify symbol colour, size, font or symbol style or combinations thereof.


During the colouring, a status message is displayed describing which map codes are currently being coloured and which colour is being applied. When colouring from a batch list the tables are processed in alphabetical order.

See Discover>Map Making>Create Map Legend for information on how to create a map legend from a coloured map.

Create a Legend from a Colour Table

ColourMap>Build Map for Colour Table

Using an existing Colour Table you have the option to create a map which displays the colour schemes relevant for the Colour Table. This option can be used after loading an existing Colour Table or when edits have been applied. Simply load up the particular Colour Table and select Build Map for Colour Table from the menu. The map can be used as a legend or style sheet for subsequent map outputs.

Colour Table Map


Export a Colour Map to Discover Mobile

ColourMap>Export to Discover Mobile

A Discover ColourMap look-up table may be exported for use in Discover Mobile. Discover Mobile provides the functionality to assign newly created map objects with a preferred map object display style. The preferred display styles are stored in the Named Styles Library and recorded in a text file titled “Named Styles.txt”. The Named Styles Library stores the display style for each map object in the same structure as a ColourMap look-up table.

Select the ColourMap>Export to Discover Mobile menu item. In the Export Colour table for PPC as dialog assign a filename and location for the text file. Click Save to create the new Discover Mobile Named Style file. This text file can now be uploaded for use into Discover Mobile. See the Discover Mobile documentation for more information on using Named Styles.

The Colour Map can also be imported in the Drillhole Legend Editor tool, for use in displaying Drillhole data by polygon styles using Drillholes>Import or Export>Import Discover ColourMap Table.

Saving and Applying Thematic Map Settings

Use Discover Auto-Shade to save thematic shade settings from a Map Window and re-apply the settings to any appropriate data set. Save and apply any type of thematic setting.

• Save Thematic Map Setting in MapInfo

• Save Thematic Map Setting with Auto-Shade

• Apply Auto-Shade Setting to Table

• Use Other Auto-Shade Files

• Use Auto-Shade with Other Discover Functions

Save Thematic Map Setting in MapInfo

The Discover Auto-Shade option has been designed to greatly enhance the portability of thematic maps. With MapInfo, when a thematic map has been created, the only way to save the thematic map is to save a workspace that includes the map window. However, if you then want to apply these thematic map settings to a different column in the same table, or to a completely different table, you must start again with the MapInfo>Create Thematic Map menu option, unless you wish to edit the workspace yourself.


Discover can store these settings in a shade file (SHD). The shade files can then be made available to other users to allow standard thematic map settings to be maintained across a project.

Save Thematic Map Setting with Auto-Shade

When you have created a new thematic map (or modified an existing one) and wish to save the settings, choose Discover>Auto-Shade. Click the Add button from the main AutoShades dialog. Discover asks you to select the thematic map layer to add (it is called LayerName (n) where n is the number of the thematic layer in the active map window), and select the shade file to add it to.

If no shade files are currently stored, you should select New Shade File from the Add to Shade File list. Note shade files have the file extension .SHD.

AutoShade dialog for selection and storing of shade files


Apply Auto-Shade Setting to Table

To apply a saved shade setting to a table, the table must be displayed as a layer in the front map window. Select the shade setting required (from the shade list and the shade file list), and select the table and column to apply it to.

By default, Discover attempts to select the same column that was used to create the shade setting. If the data column chosen contains values that lie outside the range of the shade setting, then those objects are not shaded.

If you are applying a pie or bar chart shade, then you must explicitly select the same number of columns that were used to make the pie or bar chart originally. The original columns used for this shade setting are displayed above a Choose New Columns button.

If the data that you choose cannot be thematically shaded, Discover displays an information message.

Use Other Auto-Shade Files

Using Auto-Shade, you can save a thematic map setting and then later re-apply it to any data that you wish to. The thematic map settings are stored in shade files and Discover keeps a list of the various settings and shade files that you have saved. Although there is no limit to the number of settings that you can save, you will find that it is useful to group your saved settings into separate shade files.

Shade files may be transferred from one Discover installation to another. However, when this is done, you must copy the shade file into the new Discover configuration folder and then “register” the shade file by clicking on the Add button and entering the shade file name. If there is a thematic map displayed, after clicking the Add button you should click the Add Existing Shade File button.

The shade files are stored in the configuration folder, and the list of shade files and shade settings is stored in the table AutoShade, also in the configuration folder. You do not need to explicitly open this table to run Auto-Shade.

Use Auto-Shade with Other Discover Functions

With the ColourMaps>Colour Map quick shade option, a Discover colour table can be quickly applied as a thematic map setting to a polygon table. You can then save this shade setting with Auto-Shade.

When creating a polygon grid with the Discover Surfaces Module, the best way to visualise the grid is to thematically shade it by ranges. With Auto-Shade, you can quickly apply a customised shade setting to a new grid or contours.


Use standard shade settings in conjunction with Drillhole>Display Downhole Data for a flexible downhole drill data display.

Create a thematic map for graphed data with GraphMap and apply it to the source data, then save the setting with Auto-Shade for later use

Colour Map Objects by RGB Values

Discover>Table Utilities>RGB Colourizer

The Discover RGB Colourizer utility enables map objects to be coloured based on RGB colour schemes entered as attributes in a table. The RGB Colourizer can also be used to extract RGB values from point, line or polygon map objects and save them into a table as attribute data.

RGB Colourizer dialog

1. Select the table containing the map objects from the Select Table pull-down list.

2. Select the RGB Update Method:

• Update Object Colours – colour map objects based on RGB values stored in the table


• Update Column Values - extract the RGB colour values from each map object and save them back to the table

3. The Colour Mapping options determine the RGB format to be used. The Discover RGB Colourizer can read colour values stored in either single or multi column format. The columns that store the RGB values can be numeric or character data types. Discover can also read or store colour values in BGR format.

• Multi Column format - Red, Green and Blue values are each stored in a separate column, e.g. Red (199) Green (181) Blue (181).

• Single Column format - Red, Green and Blue values have a formula applied to them to create a single number string. Using the above example, the corresponding single RGB value is as follows:

Red (199) * 65536 + Green (181) * 256 + Blue (181) = 13088181

The map objects or columns in the original table may be directly updated by selecting the Change Source Table output option. This option will cause the map objects in the table to be permanently coloured according to the Colour Mapping column or columns selected.

Note When extracting the RGB values from map objects the single or multiple RGB columns must already exist in the table. If the table does not contain these column(s) use the MapInfo Table>Maintenance>Table Structure utility to add the required columns to the table.

4. The default output option is to create a new table with the updated coloured map objects or extracted RGB values. The new table is named using the original source table with a “_Colourized” extension. To change the output table name or location, click on the Save button.

Warning The Change Source Table option is irreversible. Make sure that the RGB column or columns selected for colouring map objects are correct as map objects can be coloured according to any numerical values in the selected columns. It is recommended that a copy of the source table be saved prior to using this utility or the Create New Table output is used.


Formatting Vector Objects

Discover>Data Utilities>Plot Vectors

Discover can display velocity/flow data as oriented vectors with either a fixed vector length or with a length proportional to a magnitude attribute in the point source table.

The Discover Plot Vectors utility provides quick visualisation of vector (magnitude and orientation) data in map view. For example, water flow, soil creep, erosion rate, dune movement or any surface measurement which has a magnitude and direction component can be represented in this way. To use the Plot Vector utility, a table must contain mapped point locations, with attribute columns for the position coordinates (Easting and Northing) and the vector azimuth. An optional column can also be added to control the length of the vector magnitude.

Plot Vectors dialog

1. Select the table to create the vectors from the pull-down list.

2. Select the appropriate columns for Easting, Northing, Azimuth and Magnitude (optional).

3. From the Vector Type control, choose Vector to create vector arrows that will be proportional in length to the magnitude of the selected data column or Scalar to create vector arrows of the same length.

4. Select a vector Scale and Arrow Style. Adjust the length and aspect ratio of the Arrow Head and adjust the distance units, to suit the map scale in which you are working.


Discover will create orientated arrows at each point location according to the column information specified. You can elect to output the vectors to either the Cosmetic layer (default option), create a New Table to hold the vectors or to overwrite the existing points in the current vector table. If the original point symbols are overwritten and you wish to restore them, re-run Plot Vector utility and select the Re-create Points option. Adjust the vector scaling by again re-running the utility on the same data.

The soil creep data is displayed as oriented arrows, the arrow length being proportional to the soil creep magnitude

Cloning Object Styles

Discover>Object Editing>Clone Style

The Clone Style tool will copy the style of a selected point, line, polyline, region or text object. This style can then be applied to selected map object/s in the current or another mapper window.


Clone Style dialog

Open the Clone Style dialog. In a map window. select the object to copy the style from, and press the Copy Style button. The Clone Style tool will automatically detect and display all style attributes for the selected object.

To apply the style to other objects, check or uncheck the parameters to apply in the Paste Style Options pane. Select the target object/s to apply the style to (in the same or another map window), and press the Paste Style button.


Clone Style dialogs for line, region, symbol, and text objects


Linking Objects to External Documents

Click on a map object and display external documents or files associated with that map object. For example, Link Documents can be used to display drillhole core or location photographs when a collar is selected in the map window or open a tenement report when a tenement polygon is selected.

Document Linking or Hotlinking documents or files to map objects can be used to integrate spatial data in your GIS system with data stored in other external file formats. A map object may have one or more linked documents. When there is more than one document to display a list of linked documents is available for selection. Some of the more common linked document file types include:

• MapInfo table or workspace – If the document is a MapInfo workspace or a MapInfo table, the table is opened within the current instance of MapInfo.

• Text files – Files with the extension .TXT are opened using Notepad. Larger text files will be opened using WordPad.

• Word/Excel/Access, etc – These files are opened if there is a recognized application registered with the operating system. Therefore a .DOC file is opened using Microsoft Word, an .XLS file is opened with Microsoft Excel, etc., provided this application is present on the operating system. If there is no application registered with Windows for the linked document, Discover will display an error message.

• Raster Images - If the document to be displayed for the selected object is in a recognized raster format (such as BMP or TIF), the image is automatically registered and displayed as a MapInfo image file. Georeferenced images will be displayed as geographically registered images.

If the linked document is an image that has not been registered, Discover will automatically register the image in a non-earth projection and then display it in a new map window. This feature can be used to display photos of mineralization, thin sections or field sketches by clicking on sites of interest in the map window.

Note Each time a document is requested to be displayed, a new instance of the associated application is started.


If the image is registered in an area that lies within the current map window, then the image is loaded into this map window. If this occurs, the projection of the map window may change as MapInfo adjusts the map window projection to the image base projection. The projection of an image overrides any other file type projections within the map window. Therefore any vector data present within the map window will be warped to fit the image projection.

If two or more images are displayed in the same map window, the projection of the larger image will take precedence. If an image has already been registered, but does not fall within the map window (such as a location photo already registered into a non-earth projection), the image is opened in a new map window.

Using Discover with registered images allows the creation of a graphical imagery index. For example, the outlines of a series of remote sensing images may have been saved as polygons. Each of these polygons can be associated with the name of the image file that it represents. When a polygon is selected, the associated image can be displayed in the map window.

Any number of images can be linked to one map object and these can all be displayed simultaneously. The images can then be added to the layout window and printed out alongside the map objects to which they are associated.

Setting Up Hotlinks

Discover>Table Utilities>Document Link Setup

To link a document with a map object the full document file path must be entered into a field in the table next to the corresponding map object record. Select the Table Utilities>Document Link Setup menu option and in the HotLink Setup dialog choose the table and the column(s) to store the file path information.


The hotlink field may be created prior to entering the file path details using the Table>Maintenance>Table Structure menu option. Alternatively, click on the New Field button to add a new hotlink field to the selected table. By default the new field is named HotLink and is 255 characters in size although these parameters can be changed if desired. Make sure all hotlink fields are checked and click OK to proceed.

Creating a Hotlink

Discover>Table Utilities>Link Documents

Select one map object from the table in the map window to enter the linked document details. Choose Table Utilities>Link Documents. The Select document to associate with map object dialog is displayed.


Browse to the desired directory and select the document to link to the map object and click Open. In the Hotlink Selection dialog choose the hotlink field to store the document file path.

Click OK to finish. To permanently save the linked document file path, use the File>Save Table menu option.

To link multiple documents keep the map object selected, choose Link Documents and browse to the location of the new document to link. Choose a different Hotlink field to store the file path details.


The only limit to the number of documents that can be linked to an object is the maximum number of columns that a MapInfo table can contain (240). The same document can be linked to any number of map objects.

Opening Linked Documents

Discover>Table Utilities>Open Linked Documents

Note You can also manually enter document names into appropriate record fields.

Select a map object in the map window and either click on the Display Documents button on the Discover toolbar or select Table Utilities>Open Linked Documents. If there is only one linked document the document will be opened into MapInfo or a separate application. If there is more than one document linked to the map object select the desired document and the Preferred View from the list in the Display Document dialog.

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9 Map Making• Creating Scaled Maps

• Add a Map Grid

• Add a Scaled Frame to the Layout

• Add a Title Block and Scale Bar

• Using Object Styles

• Add a Map Legend

• Add and Format Text and Labels

• Apply SeeThru Shading

• Apply Geological Line Styles and Annotations

Creating Scaled Maps

Discover>Scaled Output

The Discover Scaled Output function gives you a wizard-style interface to simplify the creation of hard-copy output from a map window. The process can be summarised as follows:

Insert a correctly sized and scaled frame of the front map window (with map grid) into a layout. Alternatively use a layout from an existing workspace or use a mapsheet boundary to size and scale the frame. Additional frames for scalebar and titleblock are added to the layout.

Step 1 Size and scale Select the output map scale and size, and paper size required

Step 2 Additional components Select the extra components to include - map grid, titleblock and scalebar

Step 3 Refine the size and scale Refine the map position, scale and size

Step 4 Map grid Specify the Map Grid parameters


A scaled map inserted into a Layout window by Discover Scaled Output

Create Scaled Output Map

To produce an accurately scaled map using Discover, open a map window, add all the required layers and change layer settings as appropriate.

Select Scaled Output from the Discover menu, or click the Scaled Output button on the Main Button bar. Discover displays the following dialog, from which a map scale and frame size can be specified.

A range of Map Extras can be selected to automatically include in the Scaled Output Map, including a map grid, titleblock, and a scalebar.

Step 5 Title block Specify the titleblock parameters

Step 6 Output Save or print the map

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The Scaled Output dialog

Map Scale and Map Size

A range of pre-set map scales are available, or a custom scale can be specified. Selecting a pre-set scale will modify the Map Size dimensions (real world extents) displayed in the Actual Map Size box (the units of measure are defined by the Options>Preferences>System Settings parameters). The Map Size value will also be altered by the frame size (see Frame Setup) selected. If a custom scale is specified, the Map Size will not update until the Preview button is clicked.

The Set Map Position button allows you to accurately define the position of the map, see Position Scaled Output Map for more detail.

Frame Setup

Selecting a frame size from the Frame Setup list defines the size and position of the frame that Discover places into the layout window. This frame contains the map window and the size (in centimetres) is shown in the Actual Map Size box.


The frame size and orientation set here (for example, A3 Landscape) does not change the Printer Setup. Select the MapInfo File>Print Setup menu option to alter printer settings. When the Layout window is opened, it will be apparent whether the Print Set-up matches the selected frame size.

Configure Frame Settings

Discover is shipped with a list of frame settings for full page frames for all the common page sizes. You can view, edit and add to the list of page settings by choosing the Configure button on the Scaled Output dialog.

Discover allows you to set up and maintain a list of Frame Settings that define where on a particular size of paper, or a particular printer, the map should appear. When creating a new frame setting, select the page size on which you wish to base the frame and then alter the margins and frame positions. Discover allows you to base the frame on any page size in the groups A0-A5, B1-B5, C1-C5, and A-F.

You generally need to adjust your frame size to account for non-printing margins (which are different on different printers and different page layouts).

Note The page size for the Layout window can only be altered after the Layout window has been created. If you would like to set a preferred printer and page size use the Options>Preferences>Printer menu item.

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The Page Setup Configuration dialog

The Non-Printing Margins define the area around the page edge which your printer cannot use (refer to set-up information for your printer). In the layout window, these are the light grey margins. The Map Frame Position offsets define the position of the lower left corner of the map frame within the printing area. Choose Save Settings and give your new settings a name (for example, A4 Top), then choose OK to return to the Scaled Output dialog.

To remove a Frame Setting from the list click on the Remove button under the Maintain Frame Settings List control and select the frame to delete from the pull-down list.

Note The Non-Printing Margins settings are separate to the Map Frame Position. Therefore, if you increase the margin size, you will need to reduce the corresponding frame height/width to maintain a total frame size/position that fits within the paper size.

Note The Printer Setup is not stored with the Discover Page Setup list.


The Maintain Titleblock List control enables custom titleblocks to be available for selection when using Scaled Output. Custom titleblocks are configured to user-defined specifications and may contain company logos. Click on the Add button to add a new titleblock to the titleblock list. Use the Remove button to delete a titleblock from the list. See Add a Title Block and Scale Bar and Reference Manual: Customising Title Blocks for more information on creating your own titleblocks.

During the Scaled Output process the map window is re-sized relative to the layout window. Depending on the screen resolution of your computer the resulting map window may appear very small or parts may even appear off screen. To change the dimensions of the scaled output map window enter new width and height values into the Max Windows Dimensions.

Map Extras

By default, the Draw Grid option is checked. To produce a map with no map grid, uncheck this option. When Discover draws a map grid, the grid is sized to fit the frame, and grid text labels are sized appropriate for the output scale.

Titleblock and scalebar styles can be selected from the available lists. The list of available titleblocks can be maintained using the Configure option. The scalebar styles are pre-set in Discover and cannot be modified.

The Add frame border option will place a frame border around the selected titleblock in the Layout window. This can be useful if the titleblock linework is obscured by the edges of the mapper window.

From the Scalebar list, select the desired scalebar style you wish to include in the Map. If no titleblock is selected, the Scalebar will be shown separately and saved to the default Discover temporary directory. For details on how the different scalebars appear see Add a Title Block and Scale Bar.

Position Scaled Output Map

When the Preview button in the main Scaled Output dialog is pressed, Discover draws a rectangle in the current map window. If the size is not appropriate, the scale and frame settings can be altered in the dialog, and the preview MapSize updated by clicking the Preview button again. Once the size is suitable click the OK button. A text box will also pop-up inside MapInfo displaying the current Scaled Output size and scale.

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The Scaled output textbox with current parameters displayed

This rectangle (which is in a temporary table called MapSize) shows the area that is covered by the map, and is always drawn in the centre of the window. You can zoom and pan the map window as required, and drag the map size rectangle to the exact position required by selecting it. You cannot change the size of the MapSize rectangle as this will alter the predefined map scale.

If you decide that the map should be produced at a different scale or with a different frame size, choose Scaled Output>Re-Specify Parameters to display the main dialog again and change the settings.

Alternatively, the position of the Scaled Output map rectangle can be accurately specified by entering coordinates for either the centre or one of the corners of the map. Use the Set Map Position button (bottom right of the Scaled Output dialog) to ensure that the map is accurately positioned for consistent output.

Set Map Position dialog


Accept Map Position

When the MapSize rectangle covers the area you wish to print, choose Scaled Output>Accept Map Position. Discover now resizes the map window to the required area, and displays dialogs requesting input for grid generation and titleblock information.

Configure Map Grid Settings

The map grid is constructed as described in Add a Map Grid, with the important difference that the grid label font sizes are appropriate for the specified output scale. You can preview the grid appearance by clicking the Preview button.

When the map grid is drawn, the labels often appear very small on the screen, but are correctly sized for hardcopy at the nominated scale. You can draw multiple map grids by checking the Overlay Another AutoGrid option.

If you want to use the map grid as part of a workspace later on, then use the Save As button to save the map grid to a specific table name.

When map grid settings have been entered, click OK to proceed. The map grid is added to the map window.

Enter Scaled Output Title Block Details

Discover prompts you for details to insert into the titleblock, which is then displayed as a separate frame within the layout window. The titleblock is stored as a template in a non-earth "cm" based table and can be customized. The dialog displayed for data entry of titleblock details depends upon how the titleblock table is customized. See Add a Title Block and Scale Bar and Reference Manual: Customising Title Blocks for more information on creating your own titleblocks.

Select the position of the titleblock in the layout window. Also for larger paper sizes you may wish to increase the scale of the titleblock.

By default, the titleblock is saved in the Discover temp folder as TITLEBLK.TAB. If you are going to use this titleblock in the future (as part of a workspace) you should use the Save As button to save the titleblock to a new table.

Note If you change the view (pan or zoom) in any of the map windows after accepting the map position, the map scale and the appearance of the map in the Layout window is altered. Whilst Scaled Output is still running you can use the Scaled Output>Restore Map Window menu option to restore the map window to the correct aspect ratio and scale.

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The default titleblock will include the Data and Projection of the map, as displayed at the top of the dialog. Fill out titleblock’s title text and information text details as appropriate.

Choose to show the ScaleBar separate to the titleblock or to not display it in the Scaled output layout window.

A list of the various layer names of the source map can also be displayed. You can select the No List option if preferred.

You can also open a Layout template from a saved workspace file. See Add a Title Block and Scale Bar and Reference Manual: Customising Title Blocks for more information on creating your own titleblocks.

When titleblock details have been entered, click OK and the scalebar and titleblock are drawn. If you wish to cancel adding a titleblock to the scaled output, click No title.

The titleblock (and optionally scalebar) is created as an individual map window and added to the layout as a frame. This means you can switch to the titleblock map window and edit the details as required.

Modifying Scaled Output Layout

You can also change the positions of the titleblock and map window frames in the layout window. Use the MapInfo Select tool to select the frame and drag to a new position.

To re-align the titleblock frame with the map frame select both frames using the Select tool and holding down the SHIFT key. Right-mouse click in the layout window and select the Layout>Align Objects command from the pop-up menu. This is useful when the title obscures required details on the map.

You can add extra frames to the layout using the Discover Map Making>Add Scaled Frame to Layout tool.

Preserving the Linked Map Window's Scale/Extents

The Frame Object in a Layout Window is dynamically linked to its source mapper window. Zooming/panning or resizing this mapper window will have a direct (and possibly detrimental) impact on the Frame Object view.

Note Be careful not to zoom in or out or resize the titleblock map window - this could change the size of the scalebar drawn on the hard copy map.


If you intend altering the mapper window scaling or extents (for example, in order to zoom in and resize labels or change object styles), the following options are available for saving or returning to the mappers original settings:

1. If the Scaled Output menu is open and active for the current layout, use the Scaled Output>Restore Map Window command to return the mapper window to its original scale and extents

2. To save the current mapper's state before making any changes to the mapper scale/ size, enable Discover's Map Window>Save Mapper State option. To restore this saved setting, select the Map Window>Restore Mapper State option. Note that this is a one-off save and restore option that only applies to the mapper that was current when the Save Mapper State option was selected.

3. If the Layout is reused regularly, save the mapper scale/extents permanently using the Discover Map Window>Standard Views menu option. Any mapper can then be set to the scale/extents required for your layout window at any time. This is a highly recommended option.

4. As a last resort, the ELC Previous View button will restore the map window to a number of previous positions and scales after you have zoomed to make some modifications. Note that this option can only cycle backwards through previous views, not forwards, so press the button slowly, and check its view before proceeding to the next view.

For further tips on added and changing a Scaled Output Map see Scaled Output Hints.

Printing a Scaled Output Layout

To obtain a hardcopy print once Discover has generated the Layout, choose File>Print from the MapInfo menu.

Creating Additional Scaled Output Maps

If you wish to make additional maps of the same area, but using different data to that currently displayed in the map window, add, remove or customise the layers in the map window. The changes to the map window are reflected in the layout. If you want to make another map for a different area or for a different scale without quitting Scaled Output, then choose the Scaled Output>Re-Specify Parameters menu option. The size and position of the frames in the layout are not changed, but the map window is zoomed to fit the new scale.

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Scaled Output and Standard Map Sheets

Discover ships with MapInfo tables containing the 1:100,000 and 1:250,000 mapsheet boundaries over Australia. These tables can be found in the Discover\Discover_Tutorial\Other Data directory. Each sheet is a discrete, attributed, transparent polygon. You can use these boundaries, or other standard sheet boundaries that you create yourself (e.g. using the Discover>Object Offset function); to have Discover produce correctly scaled standard map sheets.

Open the appropriate mapsheet table and display it in your map window with the data that you wish to print. Then select the mapsheet you wish to use, using any of the MapInfo selection techniques, and run Scaled Output.

A standard 1:250,000 mapsheet ready to plot

Discover displays the same dialog as that shown above for User-Defined Output, however Discover detects and estimates an output scale. Because the aspect ratio of the map is defined by the selected map boundary, you cannot change the frame height and width in the frame settings configuration, but you can alter the position of the frame on the page, and change the scale that you wish to print at.

Note If you alter the size, position or zoom width of the map window at any time, the scale of the map in the layout window changes. Whilst Scaled Output is running, you can use the Scaled Output>Restore Map Window menu option to reset the map window size, position and zoom level. You should always save a workspace to ensure the layout settings are saved.


Ensure your printer set-up has the correct paper size, and then click OK. Discover correctly scales the map, and insert both the map name and number, if available, into the titleblock. If you wish to create your own standard mapsheet layers, ensure that they have fields called Name and Number so that the mapsheet name and number is recognized by the titleblock.

The scale that Discover suggests for your selected polygon is based on the area that it covers. You should always check the scale to ensure that it is what is required.

Scaled Output Hints

• If any polygon is currently selected in the front map window when Scaled Output is run, the dimensions of this polygon are used to size the map window. The selected polygon does not need to be a regular shape like a map-sheet.

• You can use the MapInfo Set Clip Region command with Scaled Output to quickly produce a plot of just that map data which lies within a given tenement.

• Use the Layout>Align Objects menu option to re-align the scalebar/titleblock frames if you have moved them.

• You can use Discover>Map Grid to overwrite or add to the Map grid added during the Scaled Output process.

• Use the MapInfo Tools>Tool Manager Overview tool to quickly add an overview map to your layout.

• Use the MapInfo Tools>Tool Manager North Arrow tool to quickly add a north arrow to your map or layout.

• Add extra frames to the layout using the Discover>Map Making>Add Scaled Frame to Layout tool. This allows you to add an accurately scaled frame to an open layout window, but does not provide map grid or titleblock options.

• When printing out drillhole cross-sections, use the Drillholes>Add Section to Layout tool that provides much of the functionality of Scaled Output.

• When running Scaled Output on a data set that takes a long time to redraw the screen, use the ESC key to interrupt the MapInfo redraws. Be careful not to cancel from dialogs for map grid and titleblock details. Alternatively, set complex or large layers to invisible until ready to print.

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• Use the Page Settings dialog to define other frame sizes such as oversized A0 for large maps, or wide margin A4 and A3 for printing small maps on large format printers (with large non-printing margins).

• If you need to make changes to the map window after it has been inserted into a layout, then you must use the pan/zoom functions with great care, otherwise the positioning and scaling of the frame in the layout is not correct..

Scaled Output map with additional layout frames

Exit Scaled Output

To quit Scaled Output, select the Scaled Output>Exit Scaled Output menu option. Discover then asks whether you would like to save the TitleBlock, ScaleBar and Map Grid (if these tables are open) and a Workspace that includes the layout, for future use. The titleblock, scalebar and map grid tables need to be saved under new names or they will be overwritten the next time that Scaled Output is used.


Exit Scaled Output dialog

Add a Map Grid

Discover>Map Grid

Accessed from the button bar or menu, the Map Grid function allows you to add a map grid to the current map window in any of the MapInfo standard projections or in a user defined custom projection. The style of the map grid is fully customisable and you can overlay multiple grids on one another (for example a Lat/Lon grid on a UTM grid). The map grid is drawn into a temporary table called AUTOGRID, which is located in the Discover temporary directory unless you nominate a different table name and location.

Draw a map grid in any projection to the front map window. This function is also available as part of the Scaled Output map making wizard (see Creating Scaled Maps).

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The Map Grid dialog

Map Grid Projection

By default (Auto option) the map window projection is automatically detected and used to construct the grid. To change the projection of the map window, use the Discover>Map Window>Favourite Projections function (see Map Projections).

If you wish to draw a map grid in another projection from the current map window projection, choose the User Defined option. A list of projections from the Discover favourite projection list is displayed. Select the projection that you wish to use from the list or use the pull-down list to select another projection. The map window projection is not changed, however the grid is drawn in the selected projection.


You can also display local (non-earth) grids and real world grids together. To display local and real world grids together, you should define and store a grid transformation setting - see Coordinate Transformations.

With one or more grid transformation settings saved, choose the Custom Coordsys option from the Projection control and select the appropriate transformation setting.

Grid Spacing

Discover suggests a rounded grid spacing based on the width of the map window. The grid spacing is in the coordinate units of the grid projection - usually metres, but degrees for Lat/Lon coordinate systems.

You can override the Discover suggested grid spacing by typing in your preferred value. For Lat/Lon grids, choose between grid spacing in decimal degrees or degrees, minutes, seconds by clicking the checkbox.

Map Grid Styles

The grid is drawn in one of three basic styles:

• Lines

• Points

• Edge ticks

These basic styles may be altered by changing the line, symbol type and colour. Additionally, you may choose to have grid labels placed in a mask outside the map frame.

For a grid drawn as lines, each grid line is a polyline with normally one node placed at each grid line intersection. Where the grid lines show substantial curvature (for example, when a Lat/Lon grid over a large area is displayed in a projected coordinate system) you may need additional nodes for each grid line. Set this value in the Other Label Options button.

Grid line labels are, by default, drawn at the left and top margins of the map window. In a map window with metres labels, choose a small font size (9 or less) so that the labels do not appear too intrusive. The grid label font size is relative to the current map window scale.

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You can also draw grid labels to the bottom and right margins of the map window. You may wish to use this option when overlaying grids in different projections, for example so that labels for a UTM grid are drawn at top and left, whilst labels for a Lat/Lon grid are drawn at right and bottom.

Other options available allow you to control the frequency of grid lines labels (choose from no labels, every line labelled or an intermediate setting), and what prefix or suffix to add to the coordinate label (for example, choose to label as E5000 or 5000 mE etc).

When you choose to have the grid labels drawn in a mask around the edge of the map, Discover creates an extra table (called AUTOGRID_MASK) to hold the mask. The map window is enlarged slightly so that the visible area of the map window (inside the mask) remains the same. In some cases the page margins accessed via Print Setup may need to be adjusted for the map to fit correctly on the page.

To save the Map Grid Style settings as default, tick Save as default settings, and when Preview or OK is clicked the style settings will be saved as default.

The three basic styles of map grid that can be generated by Discover


Save and Overlay Map Grids

Save the map grid using a unique table name with the Save As button, otherwise the map grid is written to a table named AUTOGRID in the Discover temporary folder. If you then wish to save the map grid for use later on, you need to use the Table>Maintenance>Rename Table menu option or the File>Save Copy As menu option to save AUTOGRID with a new name.

If you use the Save As button to specify a table name for the map grid, then MapGrid does not overwrite the existing map grid. Use this option when you need to save a map grid to disk for later use.

If there is already an AutoGrid table in the front map window, Discover overwrites it unless the Append to Existing AutoGrid option has been selected. If there is an AutoGrid table open but not in the front map window, Discover prompts you for a name to save this table to. If you do not want to save the old grid, click Cancel.

If you wish to overlay another grid with a different projection, choose the Overlay another AutoGrid option. After drawing the first grid, Discover displays the map grid dialog again and you should choose different parameters (different projection and probably different grid style).

When the Preview button is clicked, Discover constructs a temporary grid and then displays it as a layer in the front map window with the current gridding options. If you wish to adjust any display settings, click Preview again to apply the changes to the preview grid.

When the OK button is clicked, Discover constructs the grid and then displays it as a layer in the front map window.

Add a Scaled Frame to the Layout

Discover>Map Making>Add Scaled Frame to Layout

This tool allows a scaled frame to be added to the layout window for the front map window. The scaled frame is added to a newly created layout window if one is not currently opened.

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Adding a scaled frame to a layout

Use this tool in conjunction with Scaled Output to add additional frames, such as an overview or legend, to the layout, with the Make Custom Titleblock function or on its own when a scalebar and titleblock are not required.

Add a Title Block and Scale Bar

Discover>Map Making>Make Custom Titleblock

When the Make Custom Titleblock tool is opened, an initial dialog prompts you to select the titleblock template to edit and the scalebar and scale to use. For information on adding and removing custom titleblocks from the selectable list see Reference Manual: Customising Title Blocks.

Use the Make Custom Titleblock tool to open a custom titleblock, add details to that titleblock and optionally create a scalebar to add to the titleblock. The titleblock map window is sized to fit the extents of the titleblock so that it can be easily added to a layout window.


Initial Make Custom Titleblock dialog

Scale Bars

The titleblock shipped with Discover contains a range of scalebars to choose from. Both metric and imperial measurement system scalebars are available. The scalebar can be drawn in one of the six selectable formats.

Alternatively, create a scalebar so that it is displayed in a separate map window that can be moved in the layout independently of the titleblock. This scalebar can be saved and re-used in later layouts. To enable the correct scale to be displayed in a layout make sure the scalebar map window is displayed at a 1:1 zoom and that the scalebar frame in the layout window is scaled at 1:2 for page sizes up to 50 cm in width or at a 1:1 scale for layouts larger than 50 cm.

The main scalebar formats that can be selected from the initial dialog are as follows:

Scalebar 1

Scalebar 2

Scalebar 3

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Title Block and Scale Bar Options

The titleblock is stored as a template in a non-earth “cm” based table and can be customized. The dialog displayed for data entry of titleblock details depends upon how the titleblock table is customized. See Reference Manual: Customising Title Blocks for details on customizing the titleblock.

The default titleblock shipped with Discover presents a dialog similar to that shown below. The five Title Lines are concatenated (and centre justified). The details (Author, Reference etc.) are placed in the appropriate positions within the titleblock. The font styles used are defined in the titleblock template table on disk.

Scaled Output titleblock details dialog

Note To produce more customised scalebars, the Discover>Map Window>Show Dynamic ScaleBar provides more powerful options and you can save this scalebar at the appropriate window scale for future use. Ensure that the Dynamic Scalebar is saved at a map scale that matches the Scaled Output.


Title Block Options

Titleblock Position defines where in the layout window the titleblock frame is placed. The default is in the lower right corner of the main map frame. Normally, the titleblock is displayed in the layout as a frame on top of the map window frame. However, for customized titleblocks, you may wish to have the titleblock behind the map and you should check the Send Titleblock to Back checkbox.

By default, the titleblock is saved in the Discover temp folder as TITLEBLK.TAB. If you are going to use this titleblock in the future (as part of a workspace) you should use the Save As button to save the titleblock to a new table.

When entering titleblock information, you can specify a scale for the titleblock. By default, if the map to be printed is more than 50 cm wide, the titleblock is displayed at a scale of 1:1; otherwise the display scale is 1:2. Use this control to enter the scale required for the titleblock.

Scale Bar Options

By default the Scalebar in the format that was selected on the initial dialog will be displayed embedded in the Titleblock.

Show ScaleBar Seperately will display the Scalebar in a separate window. By default this will be saved ot the Discover temp folder as SCALEBAR.TAB If you are going to use this titleblock in the future (as part of a workspace) you should use the Save As button to save the scalebar to a new table.

If you choose Don’t Show Scalebar the scale bar will not be opened.

Layout Templates

Open Layout Template from workspace enables a workspace for a layout to be opened with a pre-defined format instead of opening a new empty layout. For example, the layout could contain extra annotation (such as north arrows, extra legends, fixed logos and legends) as well as other map windows such as an overview window for the state or country that the map is part of.

A list of the various layer names of the source map can also be displayed at a selectable location. Note that by default this list is produced, but you can select the No List option if preferred.

When creating a layout template to be used in this way, be careful that only those tables and windows required for your layout are actually open when you save the workspace. You may also need different workspaces for each different map format (paper size, orientation etc) that you wish to produce.

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Using Object Styles

Discover>Map Making>Styles Library

Apply Styles from List

When the styles library is called from the menu or button bar, the following dialog is displayed. All the styles that have been defined are shown in the list box. When an entry is highlighted, the appropriate style (symbol, line and/or fill style) is shown at the right of the dialog.

Select the style that you want, and click the Apply button. The current style is reset to that chosen (in the case shown below, the polygon styles are set to “Basalt”) and a note to that effect is shown in the message window. If there is a map window open, and a layer is editable, then the appropriate drawing tool (in this case the region tool) is selected.

Maintain a library of standard map object styles. Apply a map style to the currently selected objects or set the current drawing style. A map style can optionally be selected from a Discover Colour Table. Automatically insert a map style code as an attribute for a digitized object.


Map Styles dialog and selectable available options.

When the styles library is first called, the list is loaded into memory, making it available instantly for future calls.

To use a Discover Colour Table to select a style from, choose the Colour Table option and nominate a valid format Discover Colour Table (see the section on Colouring Map Objects for more details on colour tables).

If you want the style name to be added as an attribute to the table that you are editing, select the table and column name. Whenever an object is created or edited, the style name is added as an attribute, as well as the style being set.

To disable the current map style, click Cancel from the Map Styles dialog.

Note You cannot edit, delete or add a style for a colour table. Use the Colour Map function to do this.

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Maintain Styles Library

The styles library that ships with Discover includes styles for each of the 50 geological symbols added to the MapInfo symbol file, as well as a number of line and polygon styles. It is quite likely that you may want to extend and alter this list to incorporate your own styles.

Edit Map Object Style Entry

To edit an existing style, highlight the required style in the list box and click the Edit button. You are presented with another dialog that allows you to change the style and/or the style name.

Add or Delete Map Object Style Entry

To add a new style, click on the Add button and you are presented with the same dialog displayed for editing. You should select an Object Type, appropriate styles and then enter a name. To delete an existing style, highlight the required style and click the Delete button.

After each of these operations, the list is updated to incorporate the changes. Reference Manual: Map Styles and Symbol Fonts provides a list of the styles library shipped with Discover. The list includes all symbols in the ET GeoExplore TrueType font shipped with Discover, as well as some polyline and polygon styles.

Add a Map Legend

Discover >Map Making>Create Map Legend

The Discover Create Map Legend utility is used to create detailed legends where individual map objects contain attribute data in one or more columns. For example, a geological polygon map may contain attribute columns for geological unit, group or formation and age. The Create Map Legend menu option can create a legend using up to three of these attribute column entries in the map legend.

Note You cannot change the object type of the style you are editing.

Create a customizable legend for up to 10 layers in a multi-layered map. The order of items within the legend may be altered. The legend is created in a map window for easy insertion into a layout


As the Discover Create Map Legend tool requires the map objects to contain attribute data which can be grouped according to graphical styles it is not suitable for use with some tables. For example, a collar table may contain collars with the same graphical style but attributed with the Hole ID. The Create Map Legend utility will create a legend with every Hole ID listed as an individual entry. If there was a second attribute column which contained an entry for each collar such as “Drillhole” then this column could be used to create a legend with only one entry.

To create a simple legend for map objects based purely on map object style regardless of attribute data use the MapInfo Map>Create Legend menu option. The legend window created using this method is not a true MapInfo table and can only be edited by double-clicking in the legend window.

The Discover legend is created into a map window in Non-Earth (centimetres) projection. This allows Discover legends to be edited and scaled. Discover legends can be added to a layout using the Map Making>Add Scaled Frame to Layout tool.

Legend Tables and Columns

In order to create a Discover legend the active or front map window must contain the layers to include in the legend. Select the tables to display in the legend from the Create Legend 1 dialog.

The selected tables are displayed in the Create Legend 2 dialog.

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Dialog for legend creation. The user has already selected 4 layers to incorporate into this legend.

The tables selected are displayed in map layer order. Legend items from each table are displayed in the legend according to record order within the table. To alter the order of the legend items in a table check the Specify Order option. This will enable legend items to be sorted alphabetically or by a user-defined order such as geological age.

Choose the primary column from each table to be used for legend creation from the Legend Column 1 pull-down list. The column (or field) that you nominate for each table from the Legend Column 1 defines what objects are drawn on the legend. For example, if the nominated column is “RockCode” then Discover will create a legend entry for each unique RockCode. If then nominated column is “Age” then a unique legend entry is created for each Age grouping. The data held in Legend Columns 2 and 3 is added as supplementary text.

The legend tool only produces sensible results if the data is structured appropriately. That is, all records containing a specific value in Legend Column 1 should have the same graphic style. In the above example, all polygons having RockCode = “Czc” should have the same colour. If this is not the case, the legend may be not be created properly as the legend graphical style is obtained from the first record in the table that has each value.

Two additional columns containing text may be displayed in the legend. Make sure the text in these columns is structured correctly in relation to the column specified in Legend Column 1. The text selected for columns 2 or 3 may be obtained from a related lookup table. Select Lookup from the list of available columns and browse to the location of the look-up table. Match the column in the look-up table with the corresponding column from the Legend Column 1.


Legend Style

By default, Discover generates the Legend in one column with the title at the top and legend items at 2 cm spacing. Discover provides the option of creating the Legend in 2 columns with a user-defined line spacing. Legends can be easily edited once they are created using the MapInfo and Discover editing tools. The font style for legend titles and each text column can be set by clicking the Style button. The option to display a Legend Box Border is also available.

By default legend items will only be created for map objects that are currently visible in the map window. To include all map objects from the selected tables uncheck the Legend from objects within map window only option.

Legend Order

The order of individual items in the legend can be specified in one of the following ways:

• No ordering - items are placed into the legend in the same order that they are read from the table.

• Custom - manually order the individual items in the legend by moving them up or down the list.

• Alphabetic order - order items in ascending or descending.

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• Look-up Code from Table – order items according to a value in another column in the same table.

• Look-up Code from Look-Up Table - order items according to a value in external look-up table.

For each layer that the Specify Order option has been checked, a Legend Order dialog is displayed. A list of the legend items for that layer is displayed and the Re-Order options. With the Re-Order Mode set to Custom, use the Up, Down and Delete buttons to alter the list. Alternatively, set the Re-Order Mode to Alphabetical, either ascending (A-Z) or descending (Z-A).

When using a Look-Up Code to re-order legend items select a column from either the same table or a different one. In this instance the legend item is matched to a numeric value which Discover can use to determine the order of the legend items. These options could be used to re-order geological units by Age.

Dialog for changing the order of legend items


A map legend created by Discover

Add and Format Text and Labels

• Adding Titles to Frames

• Adding Text Labels

• Formatting Text

• Modifying MapInfo Label Angles

• Updating Labels and Tables

• Adding Line and Point Labels

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Adding Titles to Frames

Frame Titling is a Discover feature available for the Layout window to enable automatic labels to be added to map frames. The label corresponds to the map title name that can be edited in the ELC (see ELC Window Controls). To add Frame Titles to a map in the Layout Window, right click on the layout window to display a pop-up menu and select Add Frame Titles. A dialog allows you to control the placement and text style.

Adding a Frame Title in the top left insde corner of the map.

Adding Text Labels

Discover>Map Making>Add Text Labels

There are many occasions when you want to add text-style labels in MapInfo, rather than use the MapInfo object labels. When you place text in MapInfo, the text size is normally relative to the current map window scale, and MapInfo provides no easy way of showing whether the text is a sensible size when printed. The Discover Add Text Labels option overcomes this problem.

Using the Add Text Labels feature of Discover you can label map objects over an entire layer, writing those labels out to a specific map layer. The text may be placed at any angle and at any location relative to the centroid of the object. The label may be a column value or a more complex expression. Individual or groups of labels can be sized or display different text styles.

Choose Add Text Labels and the following dialog is displayed. Note that you should have a map window open and active when you run this option.

Place text labels into a map window, with text size relative to a specified map scale.


Text labels dialog and layer specification controls.

Choose the table that you wish to label from the list of tables in the front map window. If you have already selected objects and wish to label just them, choose Selection from the list of tables. If no objects are currently selected, this entry is not available.

Select the column that contains the attribute to use for the labels in the From column pull-down list.

Construct Text Label Expression

You can construct the text label from an expression using the same syntax required for the MapInfo Select and Update commands, for example - str$(Zinc) + “ %Zn ” + str$(Lead) + “ %Pb”. Select Expression from the bottom of the column pull-down list. An expression construction dialog box is displayed, similar to that available in MapInfo. Build your expression by directly writing the syntax, or picking the columns, operators and functions required from the pull-down lists.

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If the expression has valid syntax, Discover builds a temporary column containing the calculated values. To validate the syntax select the Verify button on the Expression Construction dialog. This temporary column remains available whilst the table is open, and appears in the browser window. It is not, however, saved.

If the expression has invalid syntax, further help on the syntax of MapInfo queries can be found in the MapInfo Professional documentation.

Customize Text Label Style

The Label Style may be customised for size, angle, position and font. The label Size defaults to 10 point at the current Map Window scale, but accepts any valid numeric input. Enter the required map scale. The label size is correct at this printed scale. The value suggested by Discover is based upon the map scale in the front map window.

The text Angle defaults to 0º, that is - left to right horizontal (normal text orientation).

The Offset East and Offset North values refer to the distance in millimetres at the specified map scale that the label should start from the object centroid. Check the Label Lines checkbox to display lines from the label to the object centroid. This is useful if the label is offset from the centre, or if you need to move labels to overcome over posting.

Formatting Text

Discover>Map Making>Format Text

Use Format Text to set the text font size for a specified output scale. You can also resize any selected text objects to prepare a map for printing at a new scale.

Note MapInfo text angles increase anti-clockwise from this direction so that 90º is vertically up and 270º is vertically down.

Set the current font size, or resize selected text, for a specified output scale.


Often you want to change the font size of existing text to prepare it to be displayed at a different scale. With the standard MapInfo text tool, you must have the window at the correct scale in order to get the text size correct. Using the text formatting utility in Discover you can adjust the text size by entering the font size that you want and the map scale that this size refers to. Additionally you can change the angle at which the text is displayed.

You should have a map window open and active. If you have selected text, it is altered to the style that you select. The following dialog is displayed.

Specifying text size, style and angles

Enter the Font Size and angle and the map scale at which this size is correct. The map scale defaults to a rounded value of the current Map Window scale.

The Font Size defaults to 10 point at the current Map Window scale, but accepts any valid numeric input. The Text angle defaults to 0º, i.e. left to right horizontal (normal text orientation).

Note MapInfo text angles increase anti-clockwise from this direction so that 90º is vertically up and 270º is vertically down.

Also, when you change the scale/zoom of the map window, you need to reset your text size using this menu option.

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Modifying MapInfo Label Angles

Discover>Map Making>Modify MI Label Angles

Discover uses the current label settings (such as label column, zoom layering and font) for the specified layer, but alters each label so that it displays at the required angle. If the labels for this layer are not already displayed, then Discover causes them to be displayed. If you wish to store the labels for later use, you must save a workspace for the map.

Updating Labels and Tables

Discover provides a range of functions for modifying text labels that are already on your map. Commonly text labels are stored in a table used just for map annotation purposes, and it does not contain data. Once the label has been created, the link between the data and the label is based on location only.

You may wish to alter the text labels for a number of reasons, such as:

• Having adjusted the position of sample labels to avoid over posting, you want to change the label text from the Pb assay value to the Zn assay, but keep the new label positions.

• Sample numbers have been provided as labels in a DXF file with a corresponding spreadsheet with no coordinates. You need to be able to create a MapInfo table with sample values joined to the location of the samples.

• Colour code sample assay labels using the same colour patterns as in the drillhole display module.

This feature alters the label angle for a specified map layer.

MapInfo Professional labels are drawn horizontally. There is no way to change the label angle for more than one label at once. Use the MapInfo Label Angle feature in Discover to set the label angle to a value other than zero for all objects in the layer.

Note You cannot use this Discover feature with query layers.

Note Note that these functions work with text objects and not MapInfo labels. If you need to convert MapInfo labels into text objects use the MapInfo LABELLER.MBX tool.


Update Text Labels from Table

Discover>Map Making>Update Text Labels from Table

Use this option to update the text in text objects according to the values in a nominated column. This column can be in the same table or a different table.

When updating with values from a different table, Discover joins the two tables simply by record number in the two tables. If the record order in the two tables is not appropriate then you need to join the two tables using SQL.

Update Table from Text Labels

Discover>Map Making>Update Table from Text Labels

Updating the table from text labels provides a simple method of adding the text label string into a column in the browser window. This feature is especially useful when dealing with DXF files containing sample number labels.

Recolour Text Labels with a Pattern

Discover>Map Making>Colour Text Labels from Pattern

Use this option to recolour text labels with colour patterns defined in the drillhole display module. Discover allows you to use any colour pattern that has been defined in the drillhole display module, and to colour the text objects based on the text string or alternatively, based on the value in a column.

If you want to colour the text objects using the colour definitions stored in a Discover colour table, then use the ColourMap tool (see ColourMap).

Adding Line and Point Labels

Discover>Map Making>Add Line and Point Labels

The Add Line and Point Labels option in Discover enables a user to apply text labels to point data that has been collected along regular lines such as soil geochemistry samples or ground geophysical readings. This function can be very useful for annotating detailed survey data i.e. a survey of ground magnetic readings collected at 1m intervals can be annotated at 10m intervals (display every 10th reading).

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Each line number and selected point locations can be annotated at the same time. Line labels can automatically be placed at the start and end of each line and sample points can be labelled with a value from a selected column at a user specified interval.

Select the Add Line and Point Labels option from the Map Making menu. The Line and Point Annotation dialog is displayed:

Line and Point Annotation dialog


Select the table to use as the base for the line and point annotations from the pull-down list. The table must contain a text column that stores the line number or line name for each sample point. Select this column from the Select Line column pull-down list. Select the column to use that contains the sample point number (must be a numeric field) from the Select Point column pull-down list.

The line and point labels may be added to the cosmetic layer, to another open table or into a new table. By default, the start and end of every line is labelled with the line name or number. Uncheck the relevant box to only display line labels at the start or end of a line, or to not display any line labels at all. The Label points box is also checked by default. Enter the desired point annotation spacing (for example, label every 10 points to annotate every 10th sample).

Use the Sort point column to make sure the point data column is sorted so the sample numbers are listed in numerical order in the original data table. Select to either filter by Row Order or Point Column. Discover automatically determines the Line label size and Point label size based on the scale displayed in the map window or you can enter your own label parameters.

Example of annotated soil sample lines with selected points labelled

Note Discover annotates the first and last sample in each line irrespective of the sample point annotation spacing defined.

9 Map Making 321

Apply SeeThru Shading

Discover>Map Making>Apply SeeThru Shading

Use SeeThru Shading to apply a standard shade pattern to selected polygons. The shading is created as linework or points and (if the polygon has a transparent fill pattern) does not obscure underlying map layers such as rasters. The shading is created in a separate table.

The Discover SeeThru Shading patterns are composed of lines, stripes or points that fill a polygon at a nominated spacing. Once a seethru shade has been defined, it can be saved as a named Pattern.

You can easily select an existing pattern from the list. You should specify a map scale to apply this pattern. This allows you to use the same pattern at a variety of display scales.

Apply transparent shading, as lines or points, to selected polygons.


Create SeeThru Shade Pattern

SeeThru Pattern selection dialog

SeeThru Shading Pattern Type

Choose between a Line, Point or Stripe Pattern Type. A line, brush or point style can be selected from the normal MapInfo range of line, brush and point types and colours.

You can select symbol styles from any of those available, including custom bitmaps. If you have used a custom bitmap to fill a region, then note that the bitmaps are placed as the bottom layer in the map and may be obscured by other non-transparent region fill styles.

Stripe patterns are made up of equal width stripes in alternating brush styles. Choose the stripe brush styles from the full range of MapInfo brush colours and fill patterns.

9 Map Making 323

SeeThru Shading Pattern Density and Orientation

For line and stripe patterns, choose an orientation between 0 and 180 degrees for the line to be drawn at (0º is vertical, 90º is horizontal). For point patterns, this option is unavailable.

You should then choose a Pattern Density or Width. The value suggested by Discover depends upon the current scale level of the map window, and is specified in the distance units of the map window. The closer the spacing, the longer time the pattern takes to generate.

You should also note that the pattern is suitable only for the current scale of the map. If you zoom in or out, the pattern spacing remains the same in map units, so that the pattern appearance changes (it becomes more dense as you zoom out, and vice versa).

By default, Discover places the shading in a new layer called SEETHRU, stored in the Discover Temporary folder. When you run SeeThru Shading, the existing SEETHRU table is overwritten. If a table named SEETHRU is in the front map window, you may append the new shading to it.

Use the Save As button to save the shading to a table that can be used later with a workspace.

SeeThru Shade Pattern Library

You can easily store seethru pattern definitions in the Discover SeeThru Pattern Library. Click on the Add button from the main dialog to store a new pattern, or select an existing pattern to edit or delete.

For added flexibility, you can combine line and point patterns to provide a polygon fill of complex appearance. Simply select a different pattern style and click the Add button.

Note If you combine stripes with other pattern types, the appearance of the pattern is unpredictable as Discover cannot control the order in which MapInfo draws the different elements in the pattern. To display these patterns together, select 2 seethru pattern layers, the lower one containing stripes, and the upper containing the other pattern.


Apply Geological Line Styles and Annotations

Discover>Map Making>Line Annotation

Line Annotation dialog

The Discover Line Annotation function is specifically for adding geological annotation to linework for map output. Annotation for a variety of styles is added at a user-specified spacing and size, for a specific output scale. Similar to the Discover text labelling function, the annotation appears at a different size if output is at a different scale to that specified.

Line annotations may be displayed at a specified interval by checking the Place Every control and entering a distance. Alternatively, check the Place with Cursor control to use the Annotation Tool to display the line annotation at a location along the line selected by the cursor in the map window.

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Select an Annotation Type. A Non-Text annotation may be selected from the line annotation pull-down list and includes entries such as fault, folds and shear zones. Text Annotation refers to placement of any defined text character selected from a list of all available characters (ASCII codes 32 to 255). Other attributes such as text size, colour, etc. can be selected using the Text button. The Symbol Annotation Type enables any special symbol fonts, such as ET Structural, to be selected as a line annotation. See Reference Manual: Map Styles and Symbol Fonts for a list of Structural and Geological Symbols.

For selected annotations such as Unconformities or Faults the placement of the annotation in relation to the boundary lines is important as it may be used to denote age differences between the two geological units. Discover provides two methods to use when determining placement for these types of annotations. If the Left/Facing Up box is checked, the annotation will be placed on the line and facing out towards the side or top of the map window.

Alternatively, check the Use Line Direction box to place the annotations on the left or right according to the direction in which the line has been digitized. To place the annotations on the left make sure the Left/Facing Up box is checked as well.

A selection of line annotation types available


Structure Line Styles

The Discover program appends a number of line styles to be used to represent structural or geological linear features to the standard MapInfo Line Styles list.

For example, linestyles which are used to display geological unconformities or thrust faults can be selected for use prior to creating linear map objects or to modify the appearance of existing linestyles in a table. The appended linestyles and their general use are as follows:

Geological and structural linestyles added to the MapInfo Line Styles

9 Map Making 327

If the younging direction for a selected linestyle is displaying incorrectly, select the line(s) in the map window and use the Discover Object Editing>Change Direction menu option or button to reverse the current line direction. The younging direction should now be displayed on the correct side of the line.

Note If the structural or geological linestyle spacing is not appropriate for the map scale at which the map is to be plotted, use the Discover>Map Making>Line Annotation utility to create your own custom spaced line annotations.

10 Capturing Maps as Images and Movies 329

10 Capturing Maps as Images and Movies• Saving a Map Window as a Registered Raster Image

• Making Movies and Animations from Map Windows

Additional tools for creating registered raster images are described in Raster Imagery. For information on editing, reprojecting, registering and other image functions, see Working with Images.

Saving a Map Window as a Registered Raster Image

Discover>Map Window>Convert Map to Registered Raster

The Convert Map to Registered Raster tool will convert the select map window view into a raster image in a number of compressed formats, including ECW, at the selected level of detail and resolution.

To convert any data into a registered raster, open a new map window in MapInfo Professional that contains the required tables or make an existing map window the active window.

1. Set the window dimensions and scale so the map window contains the information to save. Whatever is visible within the map window will be saved as the raster image.

2. Select Discover>Map Window>Convert Map to Registered Raster to display the Create Registered Raster dialog box:


3. Select the window you to wish to convert to a raster image from the Select Window to Save list.

4. Select the raster format from the Image Type drop down list. Available formats include *.ECW, *.PNG, *.BMP. *.JPEG, *.TIF, *.GEOTIFF (note though that Discover Mobile does not support .PNG). For best compression, save the window as an ECW. For compatibility, GEOTIFFs are also recommended as they contain an embedded EPSG code for the projection system.

5. Use the Detail drop-down list to increase the level of detail in the image from the fixed screen resolution (96 dpi). By default Discover will save an image which is double (2x) the size (width and height) of the map window on the screen.

6. Enter a value into the Transparency box to apply a transparency to the entire image (enter 0% for an opaque image).

7. Check the Set background transparent box to change the white background default.


8. Check the Create World File box to create an associated world file for the image which contains the registration information – this is useful for opening in programs without using the TAB file.

9. Click OK for the conversion to raster image to proceed.

Making Movies and Animations from Map Windows

Discover>Map Window>Make Movie or Animation

The Discover Make Movie or Animation tool is designed to capture a series of different map window views which can be then be viewed as a continuous animation sequence within MapInfo. Alternatively, the animation sequence can be exported as a movie file which can be replayed through software such as Microsoft Windows Media Player. The utility can be used to enhance presentations by adding new data layers to a map window to show the exploration history of a project area or to show the relationship between local and regional exploration features.

To optimise the animation file or movie created using the Discover Windows Animator utility adhere to the following rules:

2. An animation file can only be created from within a single mapper window.

3. Do not adjust the extents or size of the mapper window at anytime during the animation creation.

The Window Animator dialog is composed of two tab pages:

• Create/Edit - Create new or edit existing animation files

• Play - Load a saved animation file or play the animation file through a mapper window in MapInfo.

1. Make sure that the map window containing the data to be used in the animation is NOT maximised. If the map window is maximised, i.e. the map window fills the entire MapInfo screen, use the Restore Down button to display the window as “floating”.


Windows Animator Create/Edit dialog

Create Animation File

The Create/Edit tab is split into two sections:

The Frames section displays the created frame records (Captured window layers) along with buttons to capture, update, delete and save an animation or movie file.

1. Open a mapper window and adjust the window dimensions to the desired size. Arrange the data layers in the map window to display the first capture view.

The Preview section displays a preview of the captured mapper window. The Lock Window Size box should be checked after creating the first frame so that the map window dimensions are the same for all subsequent frames in the animation. To view a created frame in the Preview window select the frame in the Frames section and click the Preview Selected Frame button.


The Timing value entered is how long the captured mapper window view will be displayed in the animation or movie playback. If the animation is to move rapidly through a series of views, a short time frame should be selected. Alternatively, for an animation to change between views more slowly, longer timing values should be selected. A different timing value can be entered for each frame.

Play Animation File

Animation files can be loaded and played in order to review the final animation sequence, perform modifications to an existing animation e.g. adding new layers, adjusting timing or to save the animation as a movie file.

2. Select the New button to capture the current mapper window view. This view is added to the Frame list and is assigned the default name of ‘Frame 1’ and a default timing of 2.0 seconds. To change the default frame name click in the name cell and overwrite with the new name.

Note Do not adjust the mapper window dimensions using the cursor while creating the frame views as this will adversely affect the animation or movie file generation.

3. In the map window set up the view for the next frame capture. This may involve zooming, panning, adding new map layer(s), turning on a thematic layer or annotating map objects. Once the view is ready for capture, select the New button again and modify the frame name and timing values. Continue to update the map window view and create animation frames as required.

To change the order of the frames as they appear in the animation sequence use the buttons to the right of the Frame list. These options include; Move to First, Move to Last, Move Before and Move After.

4. Once the created animation is completed, select the Save button and navigate to a selected folder to save the animation. The animation file is suffixed with a *.ani extension.

Note The animation file created can be considered to be similar to a traditional MapInfo Workspace. The animation file stores information such as the map window dimensions, full file paths for all layers open in the map window, zoom parameters, amount of time each view is displayed along with details relating to thematic map layers, labels, style overrides, etc. When the animation file is first loaded Discover opens each of the tables from the file path listed when the animation was created. Therefore, if any of the tables referenced in the animation file are moved or delete, the animation will not load correctly.


• Play – Play animation file from start to finish. Note that the animation file will play from whichever frame is highlighted in the Create/Edit tab. If this is not the first frame then the animation may not be played in full.

• Stop – Halt the animation playback.

• Pause – Suspend the animation playback. Click Play to resume.

Windows Animator Play dialog

To load an animation Browse the Play tab of the Windows Animator dialog, select the Browse button and navigate to the folder where the animation file is stored. Once the animation file is loaded, use the following Playback Controls to review the animation:

Note If the Hide dialog during playback box is enabled, the Stop and Pause buttons will not be accessible.


Edit Animation File

Animation frames can be modified during creation or after the animation file has been saved and re-loaded into the Windows Animator utility.

1. In the Create/Edit tab click on the frame to be modified in the Frames list.

3. Modify the data display to the desired map window view.

2. With the frame selected, click on the Preview Selected Frame button. The frame view is displayed in the current map window.

4. Click on the Update button to update the selected frame with the current mapper window view. Alternatively, use the Delete button to delete the selected frame.

5. Once the modified animation is satisfactory, re-save using the Save button.


Create Movie File

The Window Animator tool can save an animation as a movie file. Movie files can be viewed in a number of different media software applications, e.g. Microsoft Window Media Player.

AVI Movie File Format

One of the oldest and still most commonly found video file formats available today is the AVI format. This was the early Microsoft file format that allowed content producers to combine audio and video into a single file. The acronym AVI stands for Audio/Video Interleave-Microsoft video format. Microsoft has since given up development of the AVI format, instead preferring to develop its own video compression technology in the form of Windows Media Video (WMV).

The AVI format has a simple architecture which means it can be run on many different systems like Windows, Macintosh, Linux and Unix. In fact many media players such as WMP, Real and QuickTime can play AVI files. As the AVI format is not suited for Internet playback, AVI files are downloaded to a PC and then played locally rather than trying to ‘stream’ the content.

To generate a movie file select the Create Movie button and enter a name for the movie file and location. A video compression dialog is then displayed. It is recommended to choose a compression option when saving a movie file, as even simple animations can have an uncompressed size of ten to hundreds of MB.


Since the AVI format is so simple, many vendors and individuals have created a Codec that can work with AVI files. Codec stands for COder/DECoder. It is a small piece of software that allows you to create or play compressed movie/audio files. MPEG-1, MPEG-2, MPEG-4, DivX ... are all examples of a Codec. AVI, ASF, WMV are file formats that can be used with a Codec. AVI is also a container format, meaning it can be made using many different codecs. MPEG-4 is a new international standard from the International Organisation for Standardization (ISO). The MPEG-4 Video is closely related to ISO H.263.

Note After creating a movie file (*.avi) the playback may appear distorted or pixelated. This may be due to incorrect Codec’s loaded on your computer. If you require a CODEC update, many resources are available on the Internet.

11 Viewing Data in Three Dimensions 339

11 Viewing Data in Three Dimensions

Discover 3D is a separate add-on module designed to work seamlessly with Encom Discover. The module is automatically disabled in the Discover menu unless the Discover 3D module has been purchased and a map window containing appropriate data tables for viewing in 3D is open.

Surfaces representing topography, geochemistry and geophysics, drillhole sections containing assays or lithological data or any other mapped data combinations created using MapInfo/Discover can be transferred to the Discover 3D interactive three-dimensional environment. Additional objects such as 3D DXF files, grid surfaces and raster images plus point and line data can be added to the 3D displays via MapInfo or directly into Discover 3D.

Drillhole projects can be viewed in 3D, with multiple downhole data displayed on the drillhole trace.

Discover 3D enables data to be viewed interactively with zooming, panning and fly-through capability. View orientations can also be taken from Discover 3D back into MapInfo and displayed in a layout for presentation purposes.

See Discover 3D Help for more information on preparing data for viewing and working within the Discover 3D environment.

12 Graphs and Profiles 341

12 Graphs and Profiles• General Purpose Graphs

• Time-Series Graphs

• Surface Grid Profiles

• Stacked Profiles

General Purpose Graphs

The GraphMap tool provides interactive data display and analysis functionality using an extensive range of 2D and 3D graphical visualisation and analysis techniques. Data exploration is a fundamental component in understanding complex patterns and relationships which may exist in your datasets, whether the data is geochemical, demographic or sales-orientated. GraphMap provides a powerful and intuitive way to identify these relationships and examine their interactions.

The GraphMap module can provide solutions to a diverse range of industries and their datasets. Some examples of use include:

• Structural geology (stereograms, rose diagrams)

• Exploration geochemistry (probability plots, scatter diagrams, ternary diagrams, box graphs)

• Sales, demographics and marketing (histograms, pie charts, line & bar graphs such as age vs. income or expenditure)

• Hydrogeological and environmental monitoring (scatter, line, box and bar graphs)

• Crime analysis (histograms, line and pie graphs)


The GraphMap tool being used to examine a structural dataset

The GraphMap utility incorporates the following key functionality:

• Extensive graph display modes, including Scatter, 3D Scatter, Bar, Histogram, Bubble, Lines, Box & Whisker, Pie, Scatter Matrix, Probability, Ternary, Stereogram and Rose.

• Linked selections between multiple graph windows

• Ability to link selections between GraphMap graphs and MapInfo mappers and browsers.

• Add background reference images to graphs to help identify relationships amongst datasets.

• Add a graph to an existing map window.

• Extensive symbology management including the ability to modify the colour, size and symbol properties using a discrete grouping variable, a continuous variable or a selection and apply these across multiple graphs.

• Create and examine relationships between multiple tables, such as collar and assay files, or stream sampling sites and temporal water quality data.


• View summary Statistics such as Median, Variance, Standard Deviation, Kurtosis, etc for an entire dataset or selection.

• Create complex derived fields using an extensive range of mathematical functions and operators.

• Save selections to either a Boolean field (i.e. attributed True or False) and apply these as a filter to subset your data. Alternatively save selections to a Group field.

• Create and import reusable selection regions for identifying groups of data.

• Export graphs as MapInfo tables.

• Export graphs as raster images.

• Export dataset, including derived fields and selection filters to a MapInfo table or a comma separated value (.CSV) file.

• Save and reload GraphMap workspaces.

Getting Started with GraphMap

GraphMap>Start GraphMap

GraphMap is accessed via the Start GraphMap item on the GraphMap menu. The tool can be started with or without a dataset being open in MapInfo. If an appropriate dataset is already loaded in MapInfo when GraphMap is started, a selection dialog will be presented for you to choose a dataset to load into the utility. Alternatively if no dataset is open in MapInfo then you can load a data file directly using the GraphMap File menu.


Various components of the GraphMap user interface

The GraphMap user interface consists of several key components. These are summarised below and described in detail later in this chapter.

• File Menu - provides facilities to load and export data

• Quick Access Toolbar – customisable toolbar of commonly used tools

• Menu Tabs – a range of menu specific ribbon bars containing the main graphing utilities

• Sidebar Windows – a number of dockable sidebar windows are available to display selected dataset fields, legends for graph selections, dataset statistics and graph data in tabular format

• Graph Windows and Tabs – main graph area to display graph windows. Graph Tabs across the top enable the individual graph windows to be brought to the front


GraphMap has been designed to work with either spatial or a spatial datasets of a univariate or multi-variate nature. Spatial datasets are represented internally in GraphMap as point locations, however these can be linked back to more complex objects (such as lines and polygons) that are open in MapInfo through the use of selections.

The following exercise explains the basics of using GraphMap. The GraphMap module contains significantly more functionality, which is described in Using the GraphMap Tool.

To create a graph with the GraphMap tool:

1. Open the GraphMap menu (Discover>GraphMap) and select the Start GraphMap option. Select a file or query to load into GraphMap from those open in MapInfo.

Alternatively choose None and open datasets from directly within GraphMap from the File Menu.The File Menu is accessed via the button in the top left-hand corner of the GraphMap dialog. This menu contains options for opening, saving and exporting graph data along with a list of recently used graph files.

2. On the Create tab, click the Builder button to open the Graph Builder dialog.


3. The bottom portion of the dialog will change to display the required axis assignments (X, Y and/or Z) appropriate to the graph type. Use the pull-down menus to assign the required data fields (e.g. X and Y fields for Scatter and Stereogram graphs, Y field for Probability graphs, X or Y fields for Bar, Histogram and Rose graphs, etc).

4. Additionally, a Group field can be assigned for any graph type, allowing the data displayed to be separated based on each unique attribute in this designated field. If required, set this using the Group pull down list on the right of the dialog. Within the following Select Groups dialog, the user can choose to display either:

• Single graph window for all the data with each group coloured separately

• Multiple graph windows, each representing a unique attribute or

• A Layout window of a matrix of graphs, each relating to a unique attribute.

• A Geo Located window in which all the graphs are arranged geographically next to the corresponding sample site.

The user must also select which groups to display from the list provided, allowing only those groups of interest to be plotted. Examples of the use of groups include separating geochemical data by geology, sampling or assay method or date; analysing sales data by suburb or product; or assessing demographic data by age group, occupation or salary levels. It is not generally recommended to use a numeric field as a Group field.

5. Press OK to generate the graph: a new graph window (or windows) will be displayed. Experiment with the graph types to create a number of graph windows.

6. To pan around a graph window, hold down the right mouse button whilst moving the mouse (or activate the Pan button on the Quick Access toolbar at the top of the GraphMap window). Use the Zoom buttons to control the view level, or the mouse wheel.

7. To make a selection from the graph window, use one of the three selection tools on the Quick Access toolbar at the top left of the GraphMap window. Once a selection is made, change to the View Menu tab, and press the Statistics button. This will open a new window displaying the statistics for the current selection, which will update with each new selection.


8. If multiple graphs based on the same dataset are open, a selection made in one will be highlighted simultaneously in all graph windows. This is an excellent way to visualise different aspects of the same selection easily.

Time-Series Graphs

Discover>Data Utilities>Temporal Trends Menu

The Discover Temporal Trends menu can be used to display temporal data (data collected at a specific time) from one or more monitoring locations. The data may be viewed as labels, bar graphs or linegraphs.

GIS has traditionally been used to display spatial relationships between data. However, in some situations such as environmental monitoring, there is often a requirement to view data from a single location as a function of time. The Temporal Trends utility enables parameter variations, such as those observed in water quality, to be displayed in this manner.

In order to display temporal data Discover must first make a copy of the data. This copy is then modified into a specific format organised by time from which the temporal trend plots are displayed. The temporal data can then be displayed in a number of different ways depending upon user requirements.

• Temporal Data Format

9. To change the symbology of the current selection, change to the Modify Menu tab and select new display options from one of the Colour, Size or Symbol pull-down menus. The selection will adopt this new style in all open graphs. Multiple selections in multiple graphs can thus be identified with user-defined symbology.

Set Colour

Set Size

Set Symbol


• Setting Up Temporal Trends Graphs

• Creating Temporal Trends Graphs

• Querying Temporal Trends Graphs

Temporal Data Format

For Discover to display the temporal components of data, the data format needs to conform to some simple guidelines.

The sample or monitoring locations should be stored in a mappable table containing the sample identifier and the X and Y coordinates. The temporal data needs to be stored as a list with one sample point to a row, the date of measurement and the measurement parameters. This table must be ordered by each date/monitoring epoch. The following is an example of the temporal data format:

Columns for the date of measurement and sample identifier are mandatory while a column for time of measurement is optional. The sample identifier should exactly match the corresponding entry in the map table. You may have as many measurement columns as are required (to the limit of 250 columns in a MapInfo table), though only one column can be used at a time to display trends.

Note You can also use GraphMap to display temporal data as GeoLocated Graphs. Graphmap provides date-time field support, including various graph types and data conditioning and selection.

Sample1 Date1 Measurement1_A Measurement1_B…….Sample2 Date1 Measurement1_A Measurement1_B…….Sample3 Date1 Measurement1_A Measurement1_B…….Sample1 Date2 Measurement1_A Measurement2_B…….Sample2 Date2 Measurement2_A Measurement2_B…….Sample3 Date2 Measurement2_A Measurement2_B…….


Setting Up Temporal Trends Graphs

Temporal Trends>Setup

Temporal Trends Setup dialog

Select the Map table (sample locations) and Attribute table (date/time measurements) from the Data Tables pull-down lists. Specify the columns to use to join the data from the Map and Attribute tables together. This will generally be the sample number or sampleID. Select the column where the Date data is stored and Time data column if required. Highlight the Attribute column(s) containing the measurement data.

When Discover processes the attribute data, it can either aggregate values based on a constant time interval (e.g. per day or per week) or use the raw date values. The Use date values from table option is recommended if the data is already aggregated. Alternatively, select the Use date ranges option to specify a time interval and an optional start and end time/date. Click OK to close the Temporal Trends Setup dialog.

Creating Temporal Trends Graphs

Temporal Trends>Graph Display

Discover displays Temporal Trend data in the form of a linegraph. A linegraph is constructed for each monitoring location allowing for multiple date readings to be readily displayed. The linegraph shows the trend in the measurement over time and can optionally include a threshold value and axis labels. The linegraph display type can be customised to set the horizontal and vertical scale, as well as axis labelling options.


Select the Graph Display option from the Temporal Trends menu to open the Temporal Trends Linegraph Display Parameters dialog:

Temporal Trend Linegraph Display Parameters dialog

The Graph Dimensions control enables a user to determine the Linegraph length and Vertical Scale of the linegraph relative to the scale of the map. The linegraph is drawn in map units.

In the dialog pictured above, a linegraph length of 10mm at a map scale of 1:20,000 produces an x-axis which is 200m long when viewed on the map. If the map scale is changed to 1:10,000, the linegraph length stays at 200m long, which is 20mm at that scale.

To determine the vertical scale, divide the maximum value by the vertical scale to give the maximum graph height for the specified map scale. The Minimum value option may be used to show only part of the y-axis range. If the measurement readings varied between 450 and 750, you may wish to set the minimum value to be displayed on the linegraph at 300, for example, rather than 0.

The linegraph will be placed by default above and to the right of the sampling point. The Horizontal and Vertical offsets may be altered to adjust this position.


There are a number of different display methods available for a Temporal Trend Linegraph. Up to two axis values may be allocated to display as threshold or compliance levels. In the Display Options controls, the user has the choice to display the axis labels for each measurement variable in the map window, display a separate legend window or to display no legend or labels at all.

Use the Save As button to save the newly created Linegraphs to a new table. To alter a linegraph parameter, simply re-generate the linegraphs from an existing table or create a new table. The options selected in the Temporal Trends Linegraph Parameters dialog may be saved using the Settings button. To apply these settings to a data file at a later date simply select the appropriate setting from the pull-down list.

Temporal Trend Linegraph showing water quality raw date measurements with separate legend

If temporal data for one or more sample points does not plot out as expected, check that the sample point identifier is exactly the same in the attribute table as in the map table. For example “PointA” is not the same as “pointa”. Make sure the identifiers match in case and number of spaces as well as having the same letters and numbers.

If you have produced a linegraph with the wrong scaling, open the Temporal Trend Linegraph Parameters dialog again and re-specify your linegraph parameters. Discover will then quickly re-draw the linegraphs and save them to a new table.

Discover cannot display temporal trends for more than 248 date intervals at once. If the attribute table has more than this number of date intervals, specify start and end dates to subset the data.


Use Temporal Trends>Graph Colouring to change the default temporal trend line style colours. The trend lines are coloured using the MapInfo thematic tool and can be annotated within this window accordingly.

Querying Temporal Trends Graphs

Temporal Trends>Graph Query

Temporal Trend Graph Query dialog

Surface Grid Profiles

Profiles over multiple surfaces may be displayed together to show, for example, topographic relief together with magnetics and soil geochemistry, allowing relationships between the surfaces to be examined. Additionally, vector data such as surface geology polygons and fault lines can be draped over the profiles, further enhancing the analysis. For more information, see Creating Grid Profiles.

Stacked Profiles

Discover>Data Utilities>Create Stacked Profiles

The Discover Stacked Profile tool creates a linegraph of a nominated field displayed along a traverse base line. Stacked profile presentations of line oriented data are frequently used in geophysical and geochemistry data analysis. Advantages offered by stacked profiles over imagery or point displays include:

• Trends and anomaly correlation between lines can be subtle and easier to identify or display in profile data compared with contouring or imagery

Use the Graph Query option to click on the linegraph and display the date and measurement value in the Temporal Trend Graph Query dialog:


• Multiple data channels can be displayed at the same time with identical or varying scaling

• Various filter operators can be applied to line data and the results optimally displayed in stacked profile form

• Stacked profiles created within Discover offer the following features:

• Control over clipping (high and low) thresholds

• Filling of a profile above or below a definable baseline (a variable area presentation)

• Linear or logarithmic scaling

In order to generate a stacked profile the data table must contain a column with a unique line identifier attribute (e.g. line number) and at least one numeric data column on which to create the profile. Open the data table to use in the stacked profile generation in a map window.

To create a stacked profile:

1. Select the Create Stacked Profile option from the Data Utilities menu and highlight the data table from the list displayed in the opening dialog. Click OK to display the Stacked Profile dialog:


2. Select the table to use for the stacked profile from the Dataset pull-down list. Select the data column to display in the profile from the Field pull-down list. Select the column containing the unique line identifying information from the Line pull-down list.

3. Check the Draw Across Nulls box to enable Discover to continue to draw a profile when a blank data field is encountered. In the event of larger gaps in the sampling interval within the one sample line, check the Distance Threshold box and enter a distance. When the distance between two sample points is greater than the value entered as the distance threshold, Discover starts a new profile on the same sampling line. If a distance threshold is not entered, a continuous profile for the line is displayed.

4. Select formatting options:


• Scaling of the field data can be linear or logarithmic and comply with the Scale Factor of the map in which the stacked profiles are displayed or in units per centimetre.

• The baseline or x-axis may be displayed with the profile. Use the Baseline pull-down list to select from the range of baseline options. A baseline may be created according to the minimum, maximum, average or median value of the data column. A user-specified baseline value can also be entered.

• In the Line Style control check the Show Base Lines box to display the base line or x-axis of the profile. Check the Show Field Lines to display the profile for the selected data column. Use the line style buttons next to each option to select the desired line style and colour.

• A profile may be filled with a solid colour to denote samples with values above or below the baseline or a user specified value. Click on the colour buttons to change the fill colour. The minimum and maximum values in the data column are automatically inserted into the Clip control. Check the Above or Below box to enter another value in order to clip the data range used to the specified data range.

The stacked profiles are output to a single table and added as a new layer to the mapper containing the source data. If you have elected to fill above or below the baseline, the fill is written to a separate layer as a series of polygon objects.

13 Using the GraphMap Tool 357

13 Using the GraphMap Tool• Starting GraphMap

• GraphMap Menus and Toolbars

• Creating Graphs

• Preconditioning Data

• Creating Derived Columns

• Viewing Data Values

• Arranging and Modifying Graph Displays

• Selecting Data in Graphs

• Multi-Table Relationships

• GeoLocated Graphs

• Displaying Statistics

• Changing the Style of Graph Objects

• GraphMap Settings

See Graphs and Profiles for an overview of the GraphMap tool and other graphing tools.

Starting GraphMap

1. On the Discover menu, click GraphMap menu.

The GraphMap menu is added to the MapInfo menu bar.


2. On the GraphMap menu, click Start GraphMap.

If a suitable dataset is already loaded in MapInfo when GraphMap is started, a selection dialog is displayed, from which you can select a dataset. If no dataset is open, then you can load a data file directly using the GraphMap File menu.

GraphMap Menus and Toolbars

• File Menu

• Quick Access Toolbar

• Menu Tabs

• Sidebar Windows

File Menu

• Open From MapInfo – allows datasets already open in MapInfo to be loaded into GraphMap.

• Open from File – opens a MapInfo .TAB, Comma Separated Value .csv, SQL Express .mdf or MS Access database file directly from the file system.

• Open Workspace – open an existing GraphMap Workspace .gmv file.

• Save Workspace – the current GraphMap session (graphs, symbology, legends, etc) can be saved as a GraphMap workspace (.gmv). Alternatively, all datasets open in the session can also be saved into the .gmv file using the Save Workspace and Data option.

• Export Graph As - either outputs one or more graph windows as MapInfo TAB files (and opens them within MapInfo) or the current graph window as a Raster image (in .PNG format).

• Save Data As - outputs the current dataset to a new MapInfo TAB file or a comma-delimited text file (.CSV), including user defined filter fields and derived-columns

• Save Legend to MapInfo – outputs the Legend window (see Load and Save Styles from Legend) to a MapInfo TAB file, and opens it into MapInfo.


• Close - closes selected datasets and all associated graphs.

• Options – displays the GraphMap Global Options dialog.

• Exit – exits the GraphMap utility.

• Recent Documents – For convenience GraphMap maintains a list of recent files in a panel to the right of the main File menu. Selecting a file from this list will load it automatically.

Quick Access Toolbar

The Quick Access toolbar is automatically docked at the top of the GraphMap dialog. The toolbar contains a number of icons relating to the selection of sample points in a graph window and general graph navigation functions as follows:

Selection

Navigation

Select by Rectangle allows a selection rectangle to be created by pressing and holding the left-mouse button and dragging the mouse. All graph point samples within the rectangle are highlighted in the graph window.

Select by Region allows a freehand selection region to be drawn around a number of graph point samples by pressing and holding the left-mouse button. Releasing the mouse button will close the region.

Select Live Rectangle - as the selection rectangle is drawn, all graph sample points within the selection region are highlighted within all graph windows automatically.

Create overlay selection region creates a permanent selection region which can be saved and reused with other datasets.

Zoom In and Zoom Out by either left-mouse clicking within a graph window or draw a rectangle to zoom to the contents.

Pan enables the graph view to be moved by clicking and dragging with the left-mouse button

3D Navigation enables rotation in graphs such as 3D Scatter and Bubble plots. Hold the left mouse button down whilst moving the mouse to rotate the view.


Customise Toolbar

The Customise Quick Access Toolbar dialog contains four customisation options:

• Select the User Customise option, and populate/reorder the right hand window with the desired tools from the left-hand pull-down list of categories. Note that some tools are mouse-button specific. Press OK to apply.

• Select either the Wheel Mouse, Laptop Pad or All Tools (default) Preset options and press OK to apply

The Quick Access Toolbar can be customised by selecting the pull-down menu at its right end, and selecting Customise Quick Access Toolbar from the drop-down menu.


The Quick Access Toolbar can also be placed below the Menu Tab ribbon bar by selecting the appropriate option either from this dialog, or from the Quick Access Toolbar drop-down menu.

The Menu Tab ribbon bar can be minimised so that it only appears when a menu tab is selected (e.g. Create, Modify, etc). Select the pull-down menu at the right end of the Quick Access Toolbar, and select the Minimise the Ribbon option.

Menu Tabs

The menu tabs provide access to the main toolbars:

Create Toolbar

The Create tab ribbon bar contains buttons for all the different available graph types, a simple graph builder wizard and the ability to assign fields in the source data table as graph axes, group or filter fields. For more information, see User Guide: Creating Graphs.

Modify Toolbar

The Modify tab ribbon bar contains buttons for enhancing the appearance of graph selections with a range of colour, size and symbol options. For more information, see Changing the Style of Graph Objects.

Data Toolbar


The Data tab ribbon bar contains buttons for making and saving graph selections. Selections can be made and viewed in both the graph window and in the source data table in MapInfo. Buttons for creating derived columns to graph from existing columns, data preconditioning to remove nulls or negative numbers and set up table relationships to link data in one table with another are also available. For more information, see Selecting Data in Graphs.

Settings Toolbar

The GraphMap Settings ribbon bar contains options to enable the programming of mouse buttons for various graph functions and modification of global settings for general and selected graphs and axes.

View Toolbar

The View menu tab ribbon bar contains buttons to control how individual graph windows are displayed and also the ability to view graph windows outside of the GraphMap module. Visibility of the side bar Data, Legend, Statistics, Relations and Properties windows can also be toggled on and off.

Current Graph Toolbar

The Current Graph menu tab contains buttons for customizing the graph display and modifying axis lines and labels,


Sidebar Windows

Data Window

The Selecting Data displays the properties of the current dataset including field names and current field assignments. It allows switching between multiple datasets. Preconditioning Data to remove nulls or replace below detection level samples will result in the creation of new transformed columns. Mathematical calculations can also be performed on existing data fields to created new derived columns (see Creating Derived Columns). The visibility of this window is toggled on/off via the View Menu tab.


Legend Window

The Legend Window displays the currently assigned symbol, colour and size for graph selections (see Load and Save Styles from Legend). The visibility of this window is toggled on/off via the View Menu tab.

Table Window

The Table Window displays the attribute data of the current dataset in a tabular format (see Selecting Data in Graphs). The visibility of this window is toggled on/off via the Data Menu or Create Menu tabs.

Statistics Window


The Selection Statistics Window displays various standard statistics for the current graph selection (see GraphMap Settings). The visibility of this window is toggled on/off via the View Menu tab.

Relations Window

The Table Relations Window displays the relationships between linked tables which enable graph data to be selected from one table and the associated records in a linked table will automatically be highlighted in another graph (see View menu tab). The visibility of this window is toggled on/off via the View Menu tab.


Properties Window

The Graph Properties Window contains options to set the font, colour, scale, offset and styling options applicable to each parameter of the graph (i.e. each axis as well as the graph background area). For more information, see Selecting Data in Graphs. This visibility of this window is toggled on/off via the View Menu tab or the Current Graph tab.

Creating Graphs

The Create Menu tab provides the tools for creating an extensive range of Graph Types. Most graph types have a number of compulsory Axis/Field Assignments (e.g. a Y field for a Probability plot): if these fields are not assigned, the user will be prompted to assign them before the graph can be created. Graphs are created by setting the required Axis/Field Assignments and then pressing the desired Graph Types button. Alternatively, the Graph Builder presents an intuitive wizard-style dialog to guide the new user through graph creation


Graph Builder

1. Graph buttons are presented on the side of the dialog. Select a Graph Type.

2. The main area of the dialog will display the compulsory (dark blue) and optional (light blue) Axis/Field Assignments (X, Y and/ Z) for the selected graph type as pull down lists. Use these pull-down lists to assign the required fields, and a preview of the graph will be displayed.

3. If satisfied with the graph type and field assignments, set a Group field if required. See the end of the Axis/Field Assignments section for information on the options available within the Select Groups dialog. Selecting either a Multi- or Layout Window display type will update the preview screen accordingly.

4. Press OK to generate the output graph/s.

Axis/Field Assignments

Each Graph Types button has a tooltip (hover the cursor over the relevant graph button) to detail the axis/field assignments required for that graph type. If unnecessary fields are assigned (e.g. Z field for a Histogram graph), then they will be ignored during graph creation.

To assign a field either:

• Select the desired assignment button from the Axis Assignment control on the Create tab and from the pop-up list, choose the required field or

The Axis/Field Assignment controls on the Display tab.

• Select/highlight the field in the Data window and then press the appropriate keyboard shortcut: e.g. the X key for the X axis, the G key for the Group assignment or the O key for the data Ordering field.

The Builder button on the Create tab opens the Graph Builder dialog, which provides an intuitive wizard-style interface to guide the user through graph creation.


• Select/highlight the field in the Data window and then press the right mouse button within the Data window to display the data pop-up menu; select the Axis Assignment option and choose the appropriate assignment

The Axis/Field Assignment controls on the Data window pop-up menu.

• The Order field can additionally be specified by dragging the target field in the Data window onto the Order area at the Data window’s base. This area will then indicate the Order field assignment until it is cleared/reset.

Order field indicator area

The following axis/field assignments are available:

Note It is possible to select multiple fields (by holding down the left mouse button and dragging over multiple items) or by using the normal SHIFT/CTRL key combinations, and assign them the same Axis/Field Assignment (e.g. to assign multiple Y fields, or to clear existing assignments)


Axis/Field Assignment

Keyboard shortcut

Description

X Axis X Sets the selected field as an X axis parameter. Multiple X field assignments are possible.

Y Axis Y Sets the field as a Y axis parameter. Multiple Y field assignments are possible.

Z Axis Z Sets the field as the Z axis parameter. Only one field at a time can be assigned as a Z field.

Group G Sets the selected field as a Group field. Data will be grouped based on each unique attribute. This is most appropriate for string fields such as company name, sample type, mesh size, lithology, etc (not for numeric data such as assays). Only one field can be assigned as the Group field at a time.

Filter F Sets the selected field as a Filter. The field must be a Boolean field (True or False) in order for it to be assigned. Filter fields can be created using the Save Selection as Filter Column icon (at the top of the Data window) or from the Data tab. Assigning a Filter field will enable you to create graph displays for only those entries marked as true in the filter. Only one field at a time can be assigned as a Filter.

Order by

[only applicable to Line Graphs]

O Set the selected field as the Ordering field – a field can be set as both an axis assignment and an ordering field.

By default a Line graph is drawn in the row order of the table (the _key field). If an Ordering field is set, points will be drawn and connected in the increasing order of this field. An example of use would be plotting a Line plot of Cu vs. Pb- set the Cu field as both the X Axis and the Order field.

Clear Space bar Clears the selected field’s current assignment.


If a Group field is assigned (whether manually or via the Graph Builder), a Select Groups dialog will be presented when a graph is created. This dialog allows the user to select one or more group items and display the graphs using one of three display options:

• Multiple Windows - a separate graph window is created for each selected/highlighted group

• Single Window - a single graph window incorporating all selected groups is created for the selected/highlighted groups. This display mode includes an option to colour each group uniquely to assist in identification.

• Layout Window - multiple plots are created in a single graph window, with plot representing one of the selected groups.

• A Geo Located window in which all the graphs are arranged geographically next to the corresponding sample site.

The Groups to be displayed must be highlighted in the list before pressing OK. The graph(s) will then be created for only those items which are selected.

Note For many graphs requiring for example a single Y field assignment, assigning multiple Y fields will result in the creation of multiple separate graphs, one for each Y field assignment.


The Select Groups dialog displayed when a non-compulsory Group field is assigned.

Graph Types

The following table lists the available graph types and their compulsory field assignments:

Normal Graphs

Map – opens the dataset as a map using the existing mapped fields (either the fields assigned using the MapInfo Table>Create Points menu option, or the Obj_X and Obj_Y fields if the data has spatial objects but no spatial columns). Alternatively, different X and Y fields can be assigned (e.g. for an Access table or for unmapped data) using one of the X & Y field assignment methods.

Scatter – scatter plots produce an XY point plot and require an X and Y field to be assigned. If only one field is assigned, the opposing unassigned axis will default to the ‘Key’ or record index field (row ID of each data entry) of the dataset. This graph type allows a Regression line to be plotted, and therefore a Residuals graph to be created; see Selecting Data.


Grouped Graphs

Line – line plots produces a continuous line profile using either an X and/or Y field assignment. If the opposing axis is unassigned it will default to the ‘Key’ or record index field (row ID of each data entry).

Bar – this utilises only an X or Y field assignment, setting the unassigned axis as the Key field. It produces a series of individual vertical bars representing the X or Y field value of each data entry. Its output is comparable to setting only the same field in either the Scatter or Line graphs.

3D Scatter – produces a 3D scatter plot, requiring X, Y and Z axis assignments. Once the 3D scatter plot is created, hold down the middle mouse button and move the mouse to rotate the 3D view. If either the X or Y axes are unassigned, they will be set to the ‘Key’ or record index field.

Bubble – produces bubble plot requiring X and Y assignments, with an optional Z assignment. Similar to output to a Scatter plot.

Table – opens a browser view of the current dataset. See Viewing Data Values for further information.

Lines – allows multiple line plots to be displayed on a single graph, using multiple Y field assignments. The following prompt will be displayed allowing each line to coloured separately. A simple legend indicating the field/colour association will be displayed at the top left of the graph to assist in identification.

Histogram – displays a graph of the count of records that fall within a predefined bin. The unique attributes are displayed as bins along either the X or Y axis, and the count is displayed on the unassigned axis. The bin size can be modified through the Graph Properties dialog (see Selecting Data in Graphs).

Individual line colour and legend for a Lines graph.


Statistics Graphs

Other Graphs

Box – produces a Box plot of the assigned Y field. If an optional X field is assigned, the dataset will be separated along the X axis based on each unique attribute within this field (e.g. sample type or lithology). Box plots display a summary of the important aspects of a distribution. The central box extends from the lower hinge (25th percentile) to the upper hinge (75th percentile) and therefore represents the middle half of the data spread. The line across the middle of the box represents the median. If the median is not positioned in the middle of the box it indicates that the data distribution is skewed. The vertical bars or whiskers which extend from the box represent the spread of the data (the minimum & maximum data points) unless outliers are present, in which case they extend to the nearest data point within a maximum of 1.5 times the inter-quartile range. Points outside the fence (or whiskers) are outliers or suspected outliers in the distribution. Points outside 3.0 times the inter-quartile range are drawn with smaller points to delineate the extreme outliers.

Pie – creates a multi-segment pie chart, where each segment represents a unique attribute within the assigned X or Y field. The arc of each segment represents the proportion (count) of that attribute in the total population. For numerical data, the bin size of each pie slice can be modified through the Graph Properties dialog

Scatter Matrix – uses multiple X and/or Y fields to create multiple scatter plots in a matrix pattern, allowing multi-element analysis/comparison. This graph type allows Regression lines to be plotted, and therefore Residuals graphs to be created; see Graph window tools (see Selecting Data in Graphs).

Probability - produces a normal probability plot of the assigned Y field(s). A normal probability plot is a graphical technique for assessing whether a data set is approximately normally distributed. The normal probability plot is constructed by plotting the ordered normal response values for the assigned field against the normal ordered statistic medians if a theoretical normal distribution. If the data set is normally distributed the resulting plot should represent a straight line. Deviations from a straight line represent deviations from normality. This can easily be converted to a log-normal probability graph by converting the Y axis to log under the Current Graph menu.

Ternary - creates a normalised scatter plot of three fields on a triangular diagram. The assignment of X, Y & Z fields is required in order to produce a Ternary plot. In order to plot a point on the triangular axes the X,Y,Z data for each row is normalised such that X+Y+Z = 1. If your data is not normalized then GraphMap will do this for you automatically.


Selecting Data

The Data window on the left off the GraphMap window lists all fields in the current dataset. Its primary function is to display the variables from the current dataset and to set Axis/Field Assignments for the various graph types. The pull-down list at the top of the Data Window allows the user to switch between open datasets.

The Data window is subdivided into sections depending on the field type:

• Numeric – lists all numeric fields (e.g. float, integer, decimal). It is not recommended to numeric fields as a Group assignment.

• String – lists all character fields

• Date – lists all date, time or date-time fields

• Derived Columns – lists any Derived Columns

• Transformed Columns – lists any Preconditioned Data

• Selection Columns – lists any fields created from a saved selection, whether they are a filter or group.

It also contains the following options:

Stereogram - displays structural measurements using dip direction (X) and dip (Y) fields. This graph type has options to display either Equal Area or Equal Angle projections, as well as plotting the data as either Lineations or Poles to Planes. These options can be accessed via the Graph Properties dialog (see Selecting Data in Graphs), and changing the Data Display or Projection options at the bottom of the list.

Rose – uses an azimuth/bearing field assigned as either an X or Y field to create a Rose diagram. The radius of each petal or bin indicates the number of data values that fall within that range. The bin size (default of 30 degrees) can be modified through the Graph Properties dialog (see Selecting Data in Graphs). Examples of use include evaluating regional structural trends, wind direction, fluid migration patterns (e.g. water or hydrocarbon), etc.

Clock - uses a two-axis display within a circle, with the X field bins incremented on the outside segments of the circle, and the Y field bins incremented within the circle as concentric rings. Sections within the circle are coloured accoridng to their frequency.


The Data window pop-up menu

Right mouse clicking in the Data window will open up the data pop-up menu. This contains the following functionality:

• The Axis Assignment option discussed in Axis/Field Assignments.

• If an existing derived column (see Creating Derived Columns) is selected, the Edit Derived column option enables the column’s expression to be edited.

The Show Table button opens a browser or table view of the dataset. See Selecting Data in Graphs for further information on this view type.

Add Derived Column allows the creation of a new field based on calculations performed on existing fields; e.g. the addition of the values of two fields to produce a new field. See Creating Derived Columns for further information.

Save Selection as Filter Column this will save the current selection to a new Boolean field with a user-specified name. The Boolean field records the selection with a True flag, whilst the unselected data is flagged as False. The selection fields can be assigned as a Filter field, allowing graphs to be created for only the filtered portion of the data set. For more information, see Axis/Field Assignments.

Setup Multi-Table Relationships allows the creation of relationships/joins between multiple parent and daughter tables. See Multi-Table Relationships for further information.

The Views button provides a number of options for visualising the data fields. Options include Tiles, Icons, List and Details. The Details view display a full range of summary Statistics for each field in the dataset.

The Data window can be moved by clicking and dragging its title bar, or by double-clicking on the title bar to undock it. To return the Data window to its default location, select the Reset Layout option on the Settings tab. The AutoHide icon at the top-right of the window allows the Data window to be toggled between a window view and tab in the left margin.


• The Preconditioning Data option allows null and negative data in the selected field to be handled correctly

• Update Column Statistics forces the statistics for all columns to be updated (viewable via either hovering the mouse over the column in the Data Window, or via the Details option of the Views button).

• To remove an existing column, use the Delete Column option. Note this does not alter the underlying MapInfo table, but simply removes it from view within GraphMap.

The Data window at the left of the GraphMap utility will display all fields present within the current dataset. Use the pull-down menu at the top of the Data window to change between open datasets.

Preconditioning Data

The Precondition Data option allows the effective handling of negative, non-numeric and zero values. It can be accessed either:

• by right-clicking on the target fields in the Data Window and selecting from the pop-up menu or

• via the Precondition Data button in the Data tab. This opens a list of the current datasets fields - select the target fields from this.


The Data Handling Options dialog, accessed via the Precondition Data option

Either option will open the Data Handling Options dialog. The default new output fields will utilise the source field name and apply a ‘_PC’ suffix; this can be altered in the top text window. The following options are provided:

• Negative Values - To ignore negative assay values in a data table check the Set negative values to box and leave the default “Null” entry. Alternatively, set all negative values to a single user-specified value.

• Check the Multiply negative values box by -0.5 to convert each negative value to a new positive assay value which is half the detection limit. Alternatively, multiply all negative values by a single user-specified value.


• Non-Numeric Values – To ignore non-numeric values in a data table check the Set non-numeric values to box and leave the default “Null” entry. Alternatively, set all non-numeric values to a single user-specified value.

• Zero Values - To ignore zero values in a data table check the Set all zero values to box and leave the default “Null” entry. Alternatively, set all zero values to a single user-specified value.

• Custom Template – To apply different replacement values for element data in a table or for multiple replacements within the same element field a custom template can be created. The template must contain three fields which contain the element name, the original assay value and the new replacement assay value. The template must be open in MapInfo in order to select it for use in the Data Handling Options dialog.

• Data Type Conversion - To convert the data type of the columns, tick the box and select the target data type from the list. For example, converting dates in a string column into a date column will improve their display in graphs.

Once the required preconditioning is applied, the new fields will appear in the Data Window under the Transformed Columns section. Set this as the required field assignment rather than the original source field for graph creation to utilise the applied preconditioning. To save the new column, use the To save this table, use the File>Save Data As>MapInfo table menu option

Creating Derived Columns

The Add Derived Column tool in either the Data Window or the Data Menu tab enables a new column to be created and populated based on mathematical and/or logical operation on existing columns. It opens the following dialog:


The Add Derived Column dialog

Formulae for a derived column are entered in the Expression pane. A name for the new derived column can be entered in the Column Name control above (if no column name is assigned, it will default to the expression syntax).

To enter an expression, place the cursor at the required insertion point within the Expression pane, and type the formula. To assist in the construction of a formula, items can be chosen from the Function, Operator, Value or Column assignment lists in the bottom half of the dialog. The expression pane also provides colour syntax highlighting and ‘intellisense’ to assist with the construction of valid formulas, enabled with the Auto Complete option.


Each field in the dataset can be inserted into a formula as either a Value or Column parameter by selecting them from the appropriate pull-down lists:

• A Value parameter references an individual cell value in the data set and must be surrounded in the Expression pane by square brackets (e.g. [Value]). A value parameter is used in functions that operate on individual values e.g. [Cu]+[Zn] or Log10([Pb]).

• A Column parameter references an entire column of cell values, and must be surrounded the Expression pane with curly brackets (e.g. {Column}). Column parameters are generally required in the statistical functions e.g. Mean({Cu}).

Both Values and Columns can be referenced in a formula in the expression pane. For example to compute the Z score for a given field you would enter the following expression, where ‘theValue’ is the field you are interested in.

([theValue]–Mean({theValue}))/StDev({theValue})

A range of mathematical and statistical functions are also available in the Functions list. Some of these functions accept Value parameters (such as the Log([value]), Sqrt([value]) and Tan([value])) whilst others require Column parameter assignments (i.e. statistical functions such as HarmonicMean({value}), Kurtosis({value}) and Count({value})). A brief summary of each Function and its required parameters is displayed at the base of the derived column dialog when each function is highlighted. Some functions may also require the insertion of another function inside them (e.g. ZScore([value], Mean({value}, StDev({value})). Assignment of the wrong parameter type for a function will result in an invalid expression error (e.g. Log10({Cu}) will return an error message, whereas Log10([Cu]) would be valid).

The ZScore function description, including required parameters and other functions

A range of Operators are available, both mathematical and logical. Logical operators (e.g. <, >=) are only applicable when the Expression type is changed to Conditional using the pull-down option to the right of the Expression window.


Creating a derived column using a Conditional Expression

Some examples of valid expressions:

[Cu]/Mean{Cu}[Pb]+[Zn]ZScore([Zn],Mean({Zn}),StDev({Zn}))

Once a new derived column is created, it will be listed within the Data Window. An existing derived field can be edited by right-clicking on the icon, and selecting the Edit Derived Field option form the pop-up menu. This will reopen the Add Derived Column dialog and the expression for the column will be displayed.

To save derived fields permanently, use the GraphMap File>Save Data As>MapInfo table menu option

Viewing Data Values

• the Table button on the Create Menu tab

• the Show Table button within the Data window or

• the Table button on the Data tab

The Table window also incorporates any derived columns or Saved Selection columns that have been created, as well as a “Selected” column. The Selected column indicates any currently selected records with a tick mark. Pressing the Show Selected Only option at the top of the Table window, will show only the selected entries in the list. This is an excellent way of viewing the browser records for a graphical selection.

The Table Window is similar to a MapInfo browser; it displays each record as a row of attributes in a browser format. The Table window can be displayed using either:


Individual records can be selected within the Table window by ticking the appropriate row within the Selected column. To select multiple records, highlight the records of interest (using SHIFT or CTRL key combinations) right-click in the window and choose the Assign Selection option from the pop-up menu. Deselect multiple records by highlighting them and use the Clear Selection option (right-click menu in the Table view).

The Table window Assign Selection menu

The Show Background Colour option will shade rows in the Table view using the current colour scheme (as applied using the Colour controls and displayed in the Legend window ).

A column can be sorted in ascending or descending order by clicking on the column title. The displayed field list can be customised (similar to the MapInfo Pick Fields option) by right clicking in the column title area: this will open a field selection list, with displayed fields highlighted. Select and deselect fields as required.

Field customisation within the Table window

Multiple columns can be filtered using the Filter button. This adds a row of filter controls above the table. Multiple fields can be filtered simultaneously.


• Numeric fields will have an operator and value control. Select an operator and enter a value: the table window will update to display only data matching the specified criteria. The asterix * functions as an exact match operator; it will convert the data and search values into strings and try to find an exact match.

String fields will have a single string control; type a search string in this to filter the table view. This is a dynamic operation: the view will be refiltered with each successive character entered. The asterix * functions as a wildcard e.g. *zoic will find entries of Cainozoic and Mesozoic.

Arranging and Modifying Graph Displays

• Closing Graphs

• Hide and Show Windows

• Arranging Graphs

• Adding a Graph to a Map Window

• Zoom, Pan and Rotation

• Axis, Scale, Background, and Other Display Options

• Displaying Legends

The View tab provides options for the display and positioning of graph and other windows. By default individual graphs are created as floating windows which can be identified by name in the graph titlebar or via tabs along the top of the main graph display area. These tabs can be hidden using the Show Tabs toggle (below). Individual graphs can be selected using these tabs or via the Window List. The arrangement of graph windows can be controlled using the Tile, Cascade or AutoTile menu options.

Closing Graphs

Graphs can be closed in a number of ways:

• Using the Close All option will close all graph displays,

• Using the Windows option under the Windows List button will present a dialog listing all the open graphs. Multiple graphs can be selected in the list and closed at once.


• The Close option under the File menu allows selected datasets to be closed. All graphs associated with a selected dataset will be closed.

• Using the individual close button at the top right of each graph

The following controls are available on the View Menu tab:

Hide and Show Windows

Graph Windows

Tiles all open graph windows in the GraphMap window.

Cascades all open graph windows

Automatically retiles all graph windows after each new graph created. This is a toggle button.

Toggles the display of the current graph window inside or outside the GraphMap application. Graph windows can also be toggled in and out by pressing “I” on the keyboard when the mouse is placed over a graph window.


Sidebar WIndows

Graph Windows

MapInfo

Toggles the Data Window On or Off

Toggles the Legend Window On or Off

Toggles the Selection Statistics Window On or Off.

Toggles the Table Relations Window On or Off

Toggles the Graph Properties Window On or Off

Toggles whether the Graph tabs are displayed or not. If not select from the available open graphs using the Window List option (below). This option helps increase the available space for graph window display.

Closes all open graph windows

Opens a list of all open graph (and table) windows. Selecting a list item will bring that graph window to the front.

Toggles the GraphMap application between displaying inside the MapInfo window and displaying outside of it. The latter option is useful when running dual monitor screens.


Arranging Graphs

Multiple graphs can be opened into the graph window display area. Each graph has a tab which, when selected, enables the corresponding graph to be displayed at the front of the other graphs. Graph windows can be dragged to new locations by clicking on the titlebar of the graph window and dragging the window to a new location.

The View Menu Tab contains additional window arrangement options as follows:

Use the icons on each graph window to Minimise, Restore or Close respectively.

Tiles all open graph windows in the GraphMap window.

Cascades all open graph windows


The GraphMap Settings also contains two Multi-Window Creation options:

• In Separate Windows – this option will display multiple graphs in a separate window for each

• In Tabbed Window – this option will display all graphs in a single window with tabs to switch between the individual graphs

Automatically retiles all graph windows after each new graph created. This is a toggle button.

Toggles the display of the current graph window inside or outside the GraphMap application. Graph windows can also be toggled in and out by pressing “I” on the keyboard when the mouse is placed over a graph window.

Toggles whether the Graph tabs are displayed or not. If not select from the available open graphs using the Window List option (below). This option helps increase the available space for graph window display.

Closes all open graph windows

Opens a list of all open graph (and table) windows. Selecting a list item will bring that graph window to the front.

Toggles the GraphMap application between displaying inside the MapInfo window and displaying outside of it. The latter option is useful when running dual monitor screens.


Adding a Graph to a Map Window

Right-click inside a graph window to display the graph shortcut menu.

View in MapInfo – Add a graph to an existing map window. In the Show in MapInfo dialog select the map window to add the graph. Enter in an X and Y origin for the graph in map window coordinates or click on the Select on Map button and click the desired location in the map window. Alter the Scaling for the graph as required and select a base output file name.

This process may add a number of layers to the map window.


Zoom, Pan and Rotation

Panning

Three methods are available:

• Hold down the right mouse button and move the mouse to reposition the graph content

• Use the arrow keys on the keyboard to pan the view in the direction of the arrow.

Zooming

Two methods are available:

• Use the middle mouse wheel to increase or decrease the zoom level. Rolling the mouse wheel in a forward direction will increase the zoom and rotating the wheel in a backwards direction will decrease the zoom level.

3D graph rotation

(e.g. 3D Scatter graphs)

Three methods are available:

• Depress and hold the middle mouse wheel and move the mouse to rotate the view.

• Hold down the SHIFT button and use the keyboard arrows to rotate the view around each of the axes.

• Select the Pan button from the top customisable Quick Access Toolbar. Depress the left mouse button in the graph window whilst moving the mouse to pan the view.

• Alternatively, select the appropriate button Zoom from the top customisable Quick Access toolbar, and either left click within the graph window, or draw a rectangle to zoom to its extents.


Axis, Scale, Background, and Other Display Options

The following options are provided for changing individual graph windows:

Right-click inside a graph window to display the graph shortcut menu.

Current Graph Controls

The Current Graph tab contains the following controls for customising the current graph:

• Grid Lines – toggles the display of grid lines for either the X or Y axes

• Select the 3D Navigation button on the top customisable Quick Access Toolbar. Click and hold the left mouse button whilst moving the mouse to rotate.

To continuously spin the graph around a fixed axis hold down the CTRL key while using the keyboard keys. Pressing the “T” key on the keyboard whilst part of the dataset is selected will re-center the rotation point on the center of the selection, rather than the center of the dataset.

Click in a graph window and use the arrows on the X and Y axes to increase, decrease and restore the axis extents.

Reset Graph – resets the graph view to the full data extents

Set Background Image – a MapInfo map window can be added as a background reference image for the current graph. Note: it is important that the spatial coordinates (data range) of the MapInfo window is the same as coordinates of the graph in which the background is being added.

Set Selection Overlay – previously defined selection overlay regions can be added to the current graph. These regions need to be created using the Create overlay selection region tool on the main toolbar. The selection overlay regions are stored on a per user basis in the “My Documents\Encom GraphMap” directory.

Show Regression Line :– adds a Regression line to Scatter and Scatter Matrix graphs. This option is not available for any other graph types.

Create Residuals Graph :– if the graph has a Regression Line plotted, this option creates a new Residual graph.


• Log Axis – applies a logarithmic scale to either axis

• Axis Label – toggles labels on the axes

• Graph Titles – inserts the graph tile into the graph window (useful when exporting the graph as an image or MapInfo table)

• Colouring – Numerous controls for the colour of axes, grid lines, labels, tick marks and backgrounds

1. Right-clicking in the graph window and selecting Properties from the pop-up menu.

2. Selecting the Properties option from the Current Graph Menu ribbon bar

This window contains a multitude of font, colour, scale, offset and styling options applicable to each layer of the graph (i.e. each axis as well as the graph background area). The last layer listed (named after the source dataset) also contains controls specific to the graph type: for instance Stereograms have options for dataset plotting (PoleToPlanes or Lineations), whilst Rose & Histograms graphs allow control of the Bin size.

Selecting Data in Graphs

GraphMap provides real time selection and visualisation functionality; data selected in a graph window is immediately highlighted in all graph windows relating to the same dataset (links between different datasets can also be setup using Multi-Table Relationships). This is an excellent way of examining different aspects of a subset of data, for example the various geochemical ratios (scatter plots, ternary diagrams) and statistical analyses (box and probability plots) of soil samples sourced from a basalt terrain vs. those from doleritic terrain.

To make a graph selection use one of the selection tools on the top customisable Quick Access toolbar:

The Properties window of the current graph is displayed on the right side of the GraphMap display, and can be accessed via two options:

Select by Rectangle allows a selection rectangle to be created by pressing and holding the left-mouse button and dragging the mouse.

Select by Region allows a freehand selection region to be drawn by pressing and holding the left-mouse button. Releasing the mouse button will close the region.


Additional selection tools are available in the Data Menu tab menu ribbon:

Selection tools

Saving Selections

Whenever a selection is made in GraphMap, it can be saved to a new field in the dataset and assigned as either a Filter or Group field. To save a selection, select either the Save Selection as Filter Column button in the Data tab or in the Data Window after making a selection (these buttons will be inaccessible if there is no current selection).

• When a selection is saved as a Filter, each record is assigned a Boolean field to record a true or false value: thus every record selected will be marked as True, whilst those not selected will be marked as False. In the Save Selection dialog set the Type as Filter, and either choose an existing column from the Selection pull-down list or type in the name for a new column. Press OK; the field will now appear within the Data Window under the Selection Columns section. This field can now be used to Filter the dataset (by assigning it as a Filter), thereby enabling graphs to be created using only the specified subset.

Select Live Rectangle - as the selection rectangle is drawn, all data within the selection region is highlighted within all graph windows automatically.

Create overlay selection region creates a permanent selection region. See Permanent selection regions below

Selects all records in the entire dataset

Deselects all records in the entire dataset

Selects all data points not currently selected (i.e. inverts the selection)

The current GraphMap selection is selected in MapInfo (providing the same dataset is open and a primary Key has been assigned).


• Saving a selection as a Group allows it to be attributed. In the Save Selection dialog set the Type as Group, and in the adjacent GroupName window enter an attribute (e.g. ‘Anomaly 1’). Either choose an existing field from the Selection pull-down list or type in the name for a new field. Press OK; the field will now appear within the Data Window under the Selection Columns section. Repeat this process for additional selections, giving each a unique attribute (e.g. ‘Anomaly 2’, ‘Anomaly 3’, etc) and utilising the same Selection field. This field can now be used to Group the dataset (by assigning it as a Group), allowing graph output to be separated by each unique attribute.

You can reuse these Filter and Group columns in a future session by saving them to a new dataset. Use the GraphMap File>Save Data As>MapInfo table to save the dataset, including Filter fields and any derived columns permanently.

Viewing Selections in MapInfo and GraphMap

Displaying Object Information

Clearing Selections

The current selection can be removed from Map, Scatter and 3D Scatter graphs using the Remove Selection option under the Current Graph tab. This will not affect the records in the dataset.

The currently assigned selection in MapInfo (e.g. a spatial or SQL selection) is selected in GraphMap (providing the same dataset is open in GraphMap and a primary Key has been assigned).

The current GraphMap selection is selected in MapInfo (providing the same dataset is open and a primary Key has been assigned).

The attributes for an individual graph object can be viewed by right-clicking in the graph window and enable the Object Info option. Place the cursor over the target object: a pop-up dialog will appear displaying the object’s attributes. An Object Info toggle is also in the Current Graph tab.


Creating Permanent Selection Regions

The New Overlay dialog displayed when a polygon selection region is created

Upon completion of the polygon, the New Overlay dialog will be displayed. The graph name is assigned as the default Overlay Name; this is the file into which the polygon will be saved. It is not recommended to use the same overlay between different graphs, unless the axes values (and the type of graph) are the same, as it will result in the incorrect display of data and selection polygons. Individual polygons can be assigned a unique name using the Polygon Name field (e.g. ZoneA, ZoneB, etc). A boundary line Colour for the region can also be set.

The X and Y coordinates for each vertex can be viewed and modified in the dialog before saving the polygon. Extra vertices can be added by entering their coordinates in the last blank row. Unwanted vertices can be deleted by highlighting the required rows (by selecting their marker cell - grey cell to the left) and pressing the keyboard DEL key.

Using the Create overlay selection region button (on the top customisable Quick Access toolbar or the Current Graph tab), multiple selection polygons can be created and saved for a particular graph. This tool functions in a similar manner to the Select Region tool; once activated, each vertex of the selection region can be added by left-mouse clicking at the desired coordinate. A double mouse-click will complete the region (or press the keyboard ESC key to cancel the region)


Pressing OK will complete the selection polygon definition and display it in the graph window.

If an Overlay region file already exists with the same name, a dialog will be presented to either Overwrite or Append to the existing overlay file. Overlays are stored as .xml files on a per user basis in the C:\Documents and Settings\username\My Documents\Encom GraphMap folder.

Pre-existing overlays can be added to a graph via the graph pop-up menu Set Selection Overlay option. Choose an appropriate overlay for the current graph and press OK.

Importing Selection Regions

MapInfo polygons can be imported into GraphMap as Selection regions, provided they are in the same projection as the destination graph. A geological example would be importing half a dozen polygons representing prospective host rock as selection regions, in order to alter the symbology of any point samples within these units, examine the statistics of these samples, and graph these samples as a scatter matrix separately to the entire dataset (Saving Selections as a Filter Column, and then setting this new field as a Filter field when creating the Scatter Matrix).

To select all data points that fall within a selection overlay region, enable the Select Rectangle tool on the main toolbar, and click once within the polygon. Clicking within the overlap of two or more overlapping regions will select the contents of all those regions. Holding down the SHIFT button allows the selection of multiple regions.

Note It is recommended that you do not mix overlays created in different graphs due to possible differences in axes range and scales and the potential for it to distort the graph. To remove an overlay from a graph, choose the None option from the Set Selection Overlay pop-up menu.


With the polygon map open in MapInfo (it can also be a selection, but cannot be polygons in the cosmetic layer), select the Import Selection Overlay option from the GraphMap menu.

The Selection Polygon Export dialog will open. Ensure the source table is selected in the Input MapInfo Table pull-down list (or *Selection* if appropriate). If required, assign a field to name individual selection regions using the Polygon Details pull-down list (e.g. lithology). Ensure the GraphMap XML Output Option is enabled, rename the output if required, and press OK.

Switch to the destination graph in GraphMap, and use the Set Selection Overlay option (pop-up menu or Current Graph tab) to choose the newly created selection overlay. If it doesn’t appear, check that the projection of the polygon table matches the dataset and that the output region colour set is visible (i.e. not a white region on a white graph background).

Multi-Table Relationships

GraphMap allows relationships to be created between multiple tables. This allows graph data to be selected, and the associated records in a linked table will automatically be highlighted in another graph.

Examples of use:

• An environmental monitoring program may have a table of 35 sample sites, and an associated table of temporal data comprising water quality measurements taken at each sample site at weekly intervals over 3 years. Plotting of all the measurements of total suspended solids (TSS) vs. flow rate as a scatter plot may indicate an anomalous grouping (e.g. high TSS and flow rates). With a Multi-Table Relationship created for these two tables, selecting the anomalous samples in the Scatter plot will automatically highlight the relevant sample sites in a Map graph of the sample site data.


• Similarly, by creating a Multi-Table Relationship between a drillhole collar and downhole data tables, various anomalous groupings of assay ratios (e.g. Cu vs. Zn) can be selected and the associated collar locations will be highlighted in a Map graph of the collar locations. Alternatively, selecting a number of collars in the Map graph will highlight all related downhole samples in any open graphs.

Multi-Table Relationships setup between drillhole data tables and a parent collar table.

To create relationships between a number of datasets:

1. Ensure that all required datasets are already open within GraphMap.

3. Assign the Parent Table from the pull-down list (e.g. the drillhole collar or sample site table). Then set the Parent Key, the identifier allowing a single record to be linked to multiple records in the Child Table. This might be a Hole_ID or Sample_Site field.

4. Assign the Child Table from the pull-down list (e.g. downhole_assays or water_quality), and the associated Child Key field.

5. The Description field will be automatically populated based on the field assignments; this can be overwritten if required.

2. Select the Setup Multi-Table Relationships button either from the Data Window or the Data tab. The Table Relationships dialog will open.

Note The Parent-Child relationship must be one-to-many (not many-to-many, or many-to-one). Also, multiple relationships can be created with the same Parent table by adding each in a new row; e.g. Collar-Assays, Collar-Lithology and Collar-Geophysics.


6. Ensure the Active tick box is enabled. This turns the selected relationship on; a GraphMap session can contain a number of Multi-Table Relationships, but these do not have to be all active at any point. Activating table relationships after they have been created is possible, either by re-entering the Table Relationships dialog, or via using the Table Relations window (accessed via the Relations button on the View tab).

7. The Must Match tick box is an optional data validation routine; enabling it will check that every Child record has an associated Parent record, and return a warning if this is not valid.

8. Press OK to close and apply the created table relationships.

GeoLocated Graphs

The GeoLocated graph functionality in GraphMap enables graphs to be created and displayed next to the geographic location of their data source. For example, downhole data can be displayed adjacent to a drillhole collar location or water monitoring data next to a sample site.

To create GeoLocated graphs the following steps are performed:


• Define Graph Type

• Create GeoLocated Graphs Wizard

• View GeoLocated Graphs

• Global Options

Define Graph Type

As there are likely to be many analytical values per location the data is generally stored in two separate tables. The point or sample site locations are stored in one table while the associated analytical data values are stored in another table.

You will firstly have to select the table and fields and graph type for each geolocated graph by the following steps -

1. Open both the point location and analytical data tables into the GraphMap module using the File menu.

2. Choose the table which contains the analytical data from the Data window pull-down list.

3. Select the Graph Builder from the Create menu. In the Graph Builder, choose the type of graph from the sidebar to use for each geolocated graph. GeoLocated graphs can be created for the following graph types:

• Scatter Plots

• Line Graphs

• Bar Charts

• Histogram

• Pie Charts

• Probability Plots

4. Select the columns to be used for X and/or Y axes for the desired graph type.


5. In order to create a Geo Located graph a Group field must first be assigned. The Group field should be assigned to primary key column in the analytical table that was used to join it to the point locations, e.g. Hole_ID, Site_ID or similar. See Axis/Field Assignmentsfor more information on setting axis and group assignments.

6. The Select Groups dialog is displayed. This dialog will list each individual entry in the selected Group column and the number of analytical records associated with each location. Geo Located graphs can be created for a selection or all of the groups in the list.

Select Geo Located as the Display Type and click OK to create the graphs. A message dialog will appear prompting you to setup geolocated graphs. Click Yes.


Create GeoLocated Graphs Wizard

The Geolocated Setup dialog will open. This will setup the necessary relationships between the Parent or Map Location table, and the Child or Attribute data tables.

The Map location is the table which contains the geographic point location information for each sample. This table must be a mappable table and have a primary key column such as Sample_ID, Site_ID or similar which directly matches an identical column in the Attribute table.

Select the location table from the Map Table pull-down list and choose the X and Y location column from the Map X and Map Y Location pull-down list.


The analytical data table is referred to as the Attribute Table. Select this table from the Attribute Table pull-down list.

The primary key columns in both the Map Location and Attribute tables must match exactly for the geolocated graphs to display correctly. Select the primary key from the Map Key pull-down list, and choose the matching primary key column from the Attribute Key pull-down list. See Multi-Table Relationships for more information.

Click OK to close the Geolocated Setup dialog.

Click OK to close the Group selection dialog. A message dialog may appear with an option to colour each individual Geolocated graph using a different colour. Select Yes or No on this dialog as desired.

View GeoLocated Graphs

The individual graphs are displayed on a larger graph which is based on the X and Y coordinates of the point location table. The Axis names reflect the analytical fields chosen for display at the Obj_X and Obj_Y location of the points.

Note To view the current table relationships select Relations from the View tab of the ribbon. A separate Table Relations window will be added to the GraphMap interface.


Use the Zoom and Pan tools on the Quick Access Toolbar to zoom in on a particular graph for viewing or to move about the window. Alternatively use the middle mouse wheel to zoom in or out. When the zoom level becomes high relative to the individual Geo Located graphs, a set of axis labels will automatically become visible. These axes are displayed for reference only and cannot be disabled.


To view individual graphs in more detail, place the cursor over a graph so that it is highlighted and then right-mouse click and select Zoom from the menu to zoom to the extents of the selected graph. To view the selected graph in a separate graph window, select the Show in Separate Display menu option.

To view the GeoLocated graphs with additional information it is possible to use either of the Set Background Image or View in MapInfo options from the right-mouse-click pop-up menu in the graph window (see Axis, Scale, Background, and Other Display Options). These options enable a map window to be added to the graph window as a background image or the graphs to be added to a map window in MapInfo respectively.

Global Options

When working with GeoLocated graphs a number of options can be set in the GraphMap Global Options dialog. This dialog is accessed via the Global button on the Settings tab of the ribbon bar. Alternatively the Global Options can be accessed via the File>Options button. The default Size of the GeoLocated graphs (in Pixels), the relative Graph Positioning and the Offset in map units can all be set from this dialog.


Displaying Statistics

The Selection Statistics window can be undocked from its default position on the main window so that it floats above the main GraphMap window by clicking on and dragging its title bar. The window can be resized in the normal way or docked to any sides of the main application using the onscreen docking control. The AutoHide icon at the top-right of the Selection Statistics window allows it to be toggled between an always open window and an auto hiding window which is accessible via the Selection Stats tab in the margin of the application.

A field can be sorted in ascending or descending order by clicking on the column name. A customised field display is available by right clicking in the column name area (similar to the MapInfo Pick Fields option): this will open a field selection list, with displayed fields highlighted. Select and deselect fields as required.

The Selection Statistics window automatically generates and displays a range of data statistics (e.g. Min, Max, Mean, Standard Deviation, Kurtosis, Variance, etc) for each field in the current selection. It is displayed via the Statistics button on the View tab.


Field display customisation within the Selection Statistics window

Changing the Style of Graph Objects

The Modify tab contains controls for modifying the Colour, Size and/or Symbol type of graph points/objects. Modifications can either be homogenous (e.g. a uniform symbol for the entire dataset) or heterogeneous (e.g. a colour scheme applied to a assay field using user-defined data ranges). To change the display symbology, the target data must be selected (use either the selection tools on the top customisable Quick Access toolbar or on the Data ribbon bar). The display options will only be applied to the selection. To select the entire dataset, use the Select All button on the Data tab ribbon bar.

• Colour

• Size

• Symbol

• Visibility

• Load and Save Styles from Legend

• Displaying Legends

Note The Modify tab will only affect raw data objects, such as scatter and line graphs. It will not affect graphs of grouped data, or statistical bins.


• Apply RGB Colours from Table

Colour

Advanced Colour Options

Both the Colour and Size control panels on the Modify ribbon bar contain Advanced buttons which open an Advanced Display Options dialog. These options provide a means to apply a number of custom or statistically-determined symbology schemes (e.g. standard deviation, log, and percentile etc) or creation of a user designed scheme. The Size and Colour dialogs have only minor differences so only the Colour option will be used as the example in this section.

To apply a single colour to a selection, click on the Set Colour palette and select the required colour. Custom colours can be created via the More Colours option at the base of the Colour palette dialog.

To colour a selection using unique attributes within a field (e.g. Company or sample type), press the Group button and choose the appropriate field from the pop-up list to apply colour by.

The Colour tab of the Displaying Legends (bottom left of GraphMap dialog) will be populated with each group’s description and its corresponding colour. These colours can be changed by double-clicking in the appropriate colour box and selecting a new colour from the colour palette.

To create a continuous linear colour range based on a numeric field (e.g. a numeric assay field), press the Linear button and choose the appropriate field from the pop-up list. The data will be divided into 10 continuous ranges using a linear scale and coloured individually.

The Advanced button allows colour to be applied using a variety of custom or statistically-determined data mapping techniques (e.g. standard deviation, log, and percentile etc) or creation of a user designed scheme. This option is detailed further under Advanced Colour Options..


The Advanced Colouring Options dialog, displaying a Log-derived data range

The Colour Column pull-down list allows selection of the field on which to base the Colour range. The Colour Method pull-down list contains an extensive number of colour mapping methods (and a custom option) to apply to the chosen data field:

• Linear - creates colour using a linear colour scheme, with each colour encompassing a data range of approximately equal magnitude i.e. the difference between the lower and upper values in each range is similar. By default this creates 10 data ranges.

Custom – allows the creation of a custom series of data ranges. Using the controls at the base of the dialog, new rows can be added by clicking the Add button, or deleted by selecting the row(s) and clicking the Remove button. All rows can be removed in one pass by clicking the Remove All button. The description, data range and colour can be edited directly in each rows grid cells by double clicking in the appropriate cells. The Count and % columns are computed automatically from the range values in the >= and < cells.

Note Entering a ranges >= and < values prior to using the Add button ensures that the new row automatically populates it’s >= value from the previous row’s < value.

Add

Remove

Remove All


• Rank - creates a colour scheme based on the Rank (relative position) of each data value with the dataset. By default the Rank method creates 32 colour ranges.

• Group – assigns a unique colour to each unique group within the selected field. This replicates the functionality of the Group button in the Colour panel. It is not recommended for continuous numeric fields (e.g. assay fields) unless a unique colour is required for each numeric value.

• Log – applies colour using a logarithmic scale, where each colour encompasses a data range of approximately equal magnitude i.e. the difference between the lower and upper values in each range is the same. By default this creates 10 data ranges.

• Exponential - applies colour using an exponential scale, where each colour encompasses a data range of approximately equal magnitude i.e. the difference between the lower and upper values in each range is the same. By default this creates 10 data ranges.

• Mean – creates two data ranges, separated by the mean data value (the second data range is >= the mean value).

• Standard Deviation (3 steps) – creates 3 data ranges distributed about the mean:

Minimum -> (Mean – 1 Standard Deviation)

(Mean – 1 Standard Deviation) -> (Mean + 1 Standard Deviation)

(Mean + 1 Standard Deviation) -> Maximum

• Percentile 4, 5 or 10 Ranges - creates a colour scheme based on the specified number of percentile breaks i.e. Percentile 5 Ranges will result in five 20% steps.

• Upper Tail (6 steps) - creates six percentile ranges designed to emphasise data in the upper portion of a distribution. The ranges are set at 0->60%, 60->80%, 80->90%, 90->95%, 95->98%, 98->100%. This method can be especially useful for geochemical data.

• Percentile Adjustable Ranges – allows modification of the number of percentile ranges by using the Add or Remove Row buttons at the base of the dialog. The lower and upper values of each range will be automatically recalculated after each change. It is not recommended to manually alter these values.

Add Row

Remove Row


• Upper Tail (8 steps) - creates eight percentile ranges designed to emphasise data in the upper portion of a distribution. The ranges are set at 0->30%, 30-60%, 60->80%, 80->90%, 90->95%, 95->98%, 98-99%, 99->100%

The colour scheme displayed by each method can be modified by selecting a Look-Up Table (LUT) from the list at the bottom right of the dialog. Individual data range colours can also be modified by double-clicking on the colour cell for that range, and choosing a new colour from the displayed colour palette.

Size

Advanced Sizing Options

The Advanced Sizing Options dialog replaces the Colour LUT list with Size Minimum, Maximum and Step controls. These can be used to control the symbol Size scheme across a series of data ranges. Alternatively, the symbol size for an individual data range can be altered by editing the corresponding size cell.

To apply a single symbol size to an entire selection, select the required size from the Set Size pull-down list.

To apply a different size for each unique attribute within a field (e.g. Company or sample type), press the Group button and select the field from the pop-up list.

The Size tab of the Displaying Legends (bottom left of GraphMap dialog) will be populated with each group’s description and its corresponding size. These sizes can be changed by double-clicking in the appropriate size column and selecting a new size from the list displayed.

To create a continuous size range based on a linear scale (e.g. assay field), press the Linear button and select an appropriate numeric field from the pop-up list.

The Advanced button allows symbol size to be applied using a variety of custom or statistically-determined data mapping techniques (e.g. standard deviation, log, and percentile etc) or creation of a user designed scheme. This option is detailed further under Advanced Sizing Options.


The Advanced Sizing Options dialog, displaying a 5 Range Percentile-derived data spread

Symbol

To apply a unique symbol type to an entire selection, select the required symbol from the pull-down Set Symbol list. Note: in order to view the newly assigned symbol in the graph it may also be necessary to increase the symbol size.

To apply a different symbol for each unique attribute within a field (e.g. Company or sample type), press the Group button and select the appropriate field from the pop-up list.

The Symbol tab of the Displaying Legends (bottom left of GraphMap dialog) will be populated with each group’s description and its corresponding symbol. These symbols can be changed by double-clicking in the appropriate symbol box and selecting a new symbol from the list displayed.

The current display settings can be removed using the Clear button within the Modify tab. This allows removal of either individual display attributes or all attributes. The Clear button can also be accessed in the Displaying Legends.


Visibility

To apply visibility filtering based on a field, firstly select a field from the Field drop-down list. This will automatically sort the unique values in the selected field.

Then use the + and - buttons control to scroll through various groups in the field. The current visibility group value will be displayed below the slider bar.

Advanced Visibility Options

The Advanced Visibility Options dialog replaces the raw field values displayed on the Visibility slider bar, with processed values depending on the Group Method selected. For example, selecting a numerical Column to Group on will provide the option to use Percentile method grouping. These percentile groups will then be displayed on the Visibility slider bar.

l

By default, only the values that match the current value set on the scroll bar will be displayed. Alternatively, all values below or above the current value can be displayed by selecting the left or right arrows.


Load and Save Styles from Legend

The Load Legend option allows you to browse for and load a previously saved GraphMap legend file (.gml). Loading and applying a legend file will override any existing styling that is applied to the current graphs.

The Save Legend menu saves the current legend scheme to a file so that it can be subsequently reused. The legend files are saved in a .gml format.

These options are duplicated within the Advanced Colour Options and Advanced Sizing Options dialogs.


Displaying Legends

The Legend window displays the current point symbol, size and colour options. Individual style attributes can be edited by opening the appropriate tab, selecting the appropriate cell and choosing from pull-down palettes/lists for the colour and symbol fields, or using the sizing arrows.

The Remove Styling options within the Legend window

The Legend window can be moved by dragging its title bar, or by double-clicking on the titlebar. To return the Legend window to its default location, select the Reset Layout button under the Settings tab. The AutoHide icon at the top-right of the window allows the data view to be toggled between a window view and tab in the left margin.

Apply RGB Colours from Table

The Load Colour from Column option provides a means to colour data points using an RGB colour value. An RGB colour value is an integer value which represents a specific combination of Red, Green and Blue colours. RGB colour values can be extracted from existing MapInfo data (see Colour Map Objects by RGB Values) or computed manually from individual RGB colours values using the following formula:

RGB = ( R x 65536 ) + ( G x 256 ) + B

If editing within the Custom tab of the Legend Window and the required attribute field is not displayed, use the Display Description, Colour, Size or Symbol buttons.

To assign a random colour to legend items click on the Random Colour Generator button.

To remove a style option from all data points, press the Remove Styling button and choose from the available options:

To apply colour by column, open the Modify tab; choose Load Colour from Column from the Column Operations menu and select the field containing the colour values you wish to colour by.


GraphMap Settings

• Mouse Buttons Settings

• Global Settings

• Reset Layout

• Graph Window Settings

Mouse Buttons Settings

The functionality of the various mouse buttons (Left, Middle and Right) can be customised using the appropriate buttons under the Settings tab.

Global Settings

The Global Options dialog

The Global button on the Settings tab opens the GraphMap Global Settings dialog. This has both General and Axis-specific controls, as well as controls applicable to All Graphs and specific graph types. Making changes within this dialog will affect all open and new graphs.


Reset Layout

Graph Window Settings

The following options are available from the Settings tab:

• In Separate Windows – this option will display multiple graphs in a separate windows.

• In Tabbed Window – this option will display all graphs in a single window with tabs to switch between the individual graphs

The Reset Layout button on the Setting tab resets all windows (Data, Legend, etc) and the Quick Access Toolbar to their default layout configurations.

14 Working with Images 417

14 Working with ImagesThe Discover Images utility adds a separate menu to the MapInfo menu bar and contains the following functionality:

• Registering and Rectifying Raster ImagesLoad raster images and perform image transformations (rubber sheeting) to correctly register an image to a selected coordinate system.

• Reprojecting an ImageReproject raster images into a new coordinate system.

• Displaying Image PropertiesView image file size, projection, X and Y coordinate extents, number of rows and columns, total pixels, image type and metadata.

• Enhancing an ImageAdjust image contrast and brightness and modify colour and gamma Red, Green, Blue channels.

• Applying Image FiltersApply smoothing and edge detection filters to image.

• Clipping an ImageClip a raster image to a region.

• Rotating an ImageRotate image by specified angle

• Converting an Image to Another FormatSave an existing image in a new image file format

• Modifying Image TransparencyApply transparency to the image.

The Discover Images utility supports BMP, JPG, PNG, GIF and TIFF raster image formats only.

Images and RAM Size

The Images Module requires at least four times the uncompressed (i.e. bitmap) image file size in free RAM in order to process an image (Rectify, Reproject, etc). For example if an image is 200Mb in size (uncompressed), at least 800MB of free RAM is required to process the image.


RAM is consumed by both running applications and Windows operating systems. As a rough guide, Windows XP consumes about 200MB of RAM, whilst WIndows VISTA utilises about 1GB (or 500MB on 1GB RAM systems). Therefore the Images module should be able to process a 250MB (uncompressed .bmp) image on a 2GB VISTA machine (assuming no other applications are running).

Recommended work-arounds for images with border-line file sizes:

1. Close all other running applications (including Discover 3D)

2. Ensure that no other large files are open in MapInfo (including images, grids and tabular data). Try closing MapInfo down, reopening and then opening just the image to be processed.

Registering and Rectifying Raster Images

Images>Rectify Image

The Rectify Image tool is a powerful utility that enables the registration of raster images in geographic real-world coordinates. Unlike image registration using MapInfo, the Discover Rectify Image tool can register and modify images that have been stretched, skewed or rotated. This process, known as “Rubber-Sheeting” enables portions of an image to stretched or warped to fit the entered control points. The greater the number of Control Points used, the more accurate this rectification process will be.

A number of Transformation methods are available, including Projective, Affine, Conformal and Higher order polynomial.

Note The Images module decompresses all images prior to processing. Many file types such as PNG, TIFF and JPG utilize extensive compression algorithms; their uncompressed file size is likely to be significantly larger than the compressed size. You can check the uncompressed size of an image under Image Properties

Note Many compressed image formats have an assortment of compression settings. If the Images module doesn’t recognize the image format (such as ECW or TIFs), try using an image processing package to convert or remove the compression settings.


Rectify Image dialog

Image Selection

To open the Rectify Image utility select the Discover>Images Menu option and choose Rectify Image from the new Images menu that is added to the MapInfo menu bar. In the following Rectify Image dialog, two options are available:

1. Select an image from the Current Image list of open raster images. For an image to be in this list it must already have an associated TAB file.

If the Load an Image File button is used to open an image without an existing TAB file, a Loading Control Points dialog will appear.

2. Use the Load an Image File button to browse for the raster image to be rectified

Note When an image is selected using the Load an Image File button Discover will search for an existing TAB file related to the selected image. If a TAB file is found (i.e. the image has been opened and/or registered using MapInfo), the Rectify Image dialog will be automatically populated with this registration information.

Similarly, if an open image file is selected Discover will automatically populate the rectification dialog with the existing registration information.


Click the Yes button to automatically create a control point at each corner of the image. This option is only useful if the real earth coordinates of these corner positions is known. To create custom control points click the No button.

The Rectify Image dialog is displayed with either no control points listed or control points listed in non-earth coordinates.

Using the Rectify Image tool

Rectify Image dialog showing entered control points

The Image Control Point list details the Image XY coordinates and Map XY coordinates for each control point along with the resulting RMS and Residual values. Additional Control Point tools are included such as control point creation and deletion buttons, positioning options and control point file tools.

To rectify a new image or modify an existing image:

1. Choose projection for rectified image.

2. Add (or edit) image control points.


3. Specify (or modify) the associated real world coordinates for each control point.

4. Save the ground control points.

5. Rectify the image.

Choose Image Projection

Add (or edit) Image Control Points

Use the Projection button to specify the rectified image projection. The projection is displayed at the top of the Ground Control Points list. The image projection can also be specified when using the Map button to capture Map X and Y values using an existing data table in an open map window.

Note Ground control points can be captured in either geographical (lat/long), projected (e.g. UTM) or non-earth coordinates. If a lat/long projection is selected the default lat/long format expected is decimal degrees.

To enter lat/long ground control points in DMS (Degrees, Minutes, Seconds) firstly select a lat/long projection by clicking on the Projection button and then check the DMS box which is displayed next to this button.

To add a new blank row to the control point list, press the New Point button. There are two options for specifying the Image X and Y coordinates:

• Manually enter Image coordinate values

Click in the Image_X or Image_Y cell and enter the image pixel coordinate. Note that the image pixel X coordinates increase to the right, whilst the Y coordinates increase downwards from the origin (0, 0) in the top left of the image.

• Select control point from Image

Click on the control point row to be edited. An icon will appear to the left of the row to indicate the selected row. Click on the Image button and move the cursor to the map window containing the image to rectify. The cursor is now displayed as a cross-hair (+). Click on the control point location in the image map window. The location of the X and Y pixel coordinates in the image are automatically updated in the control point Image_X and Image_Y cells.


Add (or edit) Map Control Points

To specify the Map (real-world) X and Y coordinates for a control point two options are available:

• Manually enter Map coordinate values

Click in the Map_X or Map_Y cell and enter the map coordinate. The map coordinate is the real-world projection coordinates for the corresponding image pixel XY location.

• Select control point from Map

Use an existing table in an open map window to locate control points. This map table may be a TAB file containing a simple polygon whose vertices correlate to the corners of the image or other vector data such as roads or features which can be used to locate the image control points.

If this is the first coordinate information to be captured from the map window for an unregistered image and no projection has been specified in the Rectify Image dialog, the following message is displayed with a request to use the current window projection. Select Yes to use the current map window projection for the rectified image.

To remove control points use the Delete Point button.

The last change applied to a control point row can be reversed using the Undo Change button

Click on the control point row to be edited. An icon will appear to the left of the row to indicate the selected row. Click on the Map button and move the cursor to the map window containing the image to rectify. The cursor is now displayed as a cross-hair (+). Click on the control point location in the map window. The location of the X and Y coordinates in the map window are automatically updated in the control point Map_X and Map_Y cells.


If the image is already registered, and the current map window is in a different projection to the image registration, the following warning message will be displayed.

Save Control Points

View Ground Control Points

Synchronise Modified Ground Control Points to Map/Image Control Point Locations

Synchronise Modified Map/Image Control Point Locations to Ground Control Points

Image and Map control points can be saved to a separate TAB file using the Save Control Points button. By default, the output file name is the image name with a “_gcp suffix”. Saving control points is recommended especially when a large number of control points are used to rectify an image. To use a saved control point table use the Load Control Points button.

To view the location of either loaded or newly created ground control points in the Image or Map windows, use the View GCP button. To view, simply select the particular ground control point/s you wish to observe and press the View GCP button.

If you have performed any modifications on the existing ground control points such as updating Image or Map X and Y coordinates and you wish to update the modifications on either the unregistered Image or existing Map layer, simply press the Sync GCP->Map button.

If you have moved any of the control point locations in either the unregistered Image or existing Map layer, and you wish to update the ground control point coordinates in the Rectify Image dialog, simply press the Sync Map->GCP button.


Rectify

Rectify Image Options

Click on the Options button to open the Rectify Options dialog. Use the Interpolation pull-down list to select an interpolation method from the following options:

• Nearest Neighbour - simple interpolation whereby pixels are copied into the spaces created when original pixels are spread to make a larger image and the value for the new pixel taken from the closest pixel in the original image.

• Bilinear - the value of a sub pixel in the new image is assigned the weighted value of the four surrounding pixels in the original image.

• Bi-cubic – uses the weighted value of 16 surrounding pixels in the original image to interpolate the value a sub pixel in the new image. This method requires more processing but is more accurate than bilinear interpolation. Bicubic interpolation also produces a smoother image.

To allow automatic sequential movement between rows when using the Image or Map buttons to capture point coordinates, check the Automatically move to next record box.

Press the Rectify button to start the rectification process. Note that at least three control points with both image and map coordinates are required for this process. The more control points specified the more accurate the rectification process will be.

A Save As dialog will prompt for an output file name and location. By default the output rectified table will contain the original image file name with a “_rectified” suffix. The rectified image table is automatically saved to the same directory as the original image. When the Save button is pressed, a status bar is displayed at the bottom of the Rectify Image dialog showing the rectification progress status. When the rectified processing is completed, the rectified image is displayed in a new map window.


Transformation Methods

Rectify Image Transformation methods menu

By default Discover has an internal “Auto select best method” when determining the optimum projection transformation method during image rectification. Use the Transformation pull-down list to select a specific transformation from the following options:

• ConformalConformal transformations preserve shapes and angles and may include a rotation, a scaling and a translation. Straight lines and parallel lines remain straight and parallel in the transformed image. A minimum of three control points are required for a conformal transformation.

• AffineAffine transformations enable the x and y dimensions to be scaled or sheared independently and may also include a translation. Straight lines and parallel lines remain straight and parallel in the transformed image but rectangles become parallelograms. A minimum of three control points are required for an affine transformation.

• ProjectiveProjective transformations map lines to lines. Straight lines remain straight but parallelism may not be preserved. A minimum of four control points are required for a projective transformation.

• Polynomial TransformationsPolynomial transformations are higher-order non-linear transformations which can handle more complex local distortions. Polynomial transformations are smooth and are also known as ‘rubber-sheet’ transformations as they enable parts of an image to be stretched or warped to fit the control points. A minimum of six control points for 2nd order polynomial and ten control points for 3rd order polynomial transformations is required.


Note that the “Auto select best method” option will choose the best transformation method based on the number of control points provided. The current auto-selected transformation is displayed at the bottom of the Rectify Image dialog.

Reprojecting an Image

Images>Reproject Image

The Reproject Image utility enables an image which is currently registered in one coordinate system to be reprojected and viewed in a new coordinate system. For example, images registered in Australian AGD84 coordinates can be reprojected into GDA94 coordinates. Images can be reprojected between projected (e.g. UTM), geographic (e.g. Lat/Long) and custom coordinate systems. This operation relocates the various pixel locations in the image through an interpolation method to match the requested output coordinate system.

In the .TAB file associated with a registered image the coordinates for the image extents are stored as both real-world coordinates and image pixel coordinates along with the coordinate system details. When an image is reprojected to another coordinate system, a new image and .TAB file is created containing the real-world coordinates in the new projection and the new coordinate system details. The following example details how to reproject a scanned geological image from UTM projection AMG Zone 54 (AGD84) into MGA Zone 54 (GDA94) projection.

1. Open the Image Reproject dialog and select the image to reproject from the Select Table pull-down list. The Current Projection is automatically displayed.


Output Options

3. Select a name for the reprojected image file.

By default, a new reprojected image file and .TAB file are created using the original image name and a “_reproject” extension. To change the output file name click on the new name and modify. Alternatively, click on the Save button and select a new name and/or location for the reprojected image files.

4. Select an Interpolation Method from the following:

2. Click on the Browse button and select the New Projection using the Category and Category Members options.

Note The projection list available in the Discover Image Reproject utility is stored in a separate file to the MapInfow.prj file. Therefore not all the projections in the MapInfow.prj will be available for selection in this utility. If you wish to reproject images into a custom coordinate system which has been added to the MapInfow.prj file then copy the custom projection line into the Encom.prj file located in the ...\Program Files\Encom\Common\Projections folder.


• Bilinear - the value of a grid cell in the new image is assigned the weighted value of the four surrounding image cells in the original image.

• Bi-cubic – uses the weighted value of 16 surrounding image cell values in the original image to interpolate the value a grid cell in the new image. This method requires more processing but is more accurate than bilinear interpolation. Bicubic interpolation also produces a smoother image.

• Nearest Neighbour - simple interpolation whereby the new image cell value is taken from the closest image cell in the original image.

5. Select a colour from the Null Colour palette. This colour will be used for all the null image cells around the reprojected image.

6. Click OK to create the reprojected image files.

Image Tool

Aside from the Rectify Images and Reproject Images utilities all the other Image menu options open the Image Tools dialog. Raster images must have an associated TAB file and be open in MapInfo in order to be available for selection in this dialog. All open raster images are listed in the Select Image pull-down list. Each images utility is located in a separate tab and the selected image is displayed in the preview window on the right of the dialog. The image is displayed by default in the preview window using the image height/width aspect ratio. To fill the entire preview window with the image uncheck the Match Aspect box.

As changes are made the preview window image is automatically updated. To turn off the automatic update, uncheck the Auto Update box. If any changes are made in manual mode, click the Update Preview button to update the changes to the preview window image. Changes can be made in one or more tabs and then saved. Prompts to enter a saved image name and location are displayed when the OK button is clicked.

Note Check the Use NTv2 grid-shift method if available box when reprojecting images between NAD27 and NAD83 Canadian coordinate systems or AGD66 and AGD84 Australian systems. If you are not familiar with this method see Reference Manual: NTv2 Transformation for more information about this option.


Displaying Image Properties

Images>Image Properties

Image Properties Tab

The Images Properties tab displays information about the selected raster image such as:

• SizeThe number of rows (X) and columns (Y) in the image are recorded along with the Total number of pixels in the image. The Compressed Size of the image on disk and the approximate Uncompressed Size of the image in memory. The image Type (PNG, JPG, etc) is also displayed.

• RegistrationThe name of the raster image coordinate system and the parameters as listed in the MapInfo projection file are displayed along with the minimum and maximum image X and Y coordinate extents.


• MetadataSome images may contain metadata or information about the image which is hardcoded into the image file. If a raster image contains this type of metadata it will be displayed in the Metadata in Image window. Note that this feature does not read metadata which has been entered into the .TAB file of the image.

Enhancing an Image

Images>Enhance Image

Enhance Image tab

Use the Enhance Images tab to modify the appearance of a raster image.

• Contrast/BrightnessAdjust the lightness of an image by changing the Contrast and Brightness levels. The original image contrast and brightness level is set to 0. Positive values will lighten and increase the contrast whereas negative values will darken an image and decrease the contrast.

• Grey ScaleConvert a coloured image to black, white and 254 shades of grey.


• Invert ColoursEach RGB pixel value is subtracted from 255 and replaced with the corresponding colour to create a negative image.

• ColourAdd or subtract a value to each RGB colour.

• GammaAdjust the overall brightness of an image using the individual red, green and blue channels. Positive gamma values will lighten each channel of the image and negative gamma values will darken each channel of the image.

Applying Image Filters

Images>Filter Image

Filter Image tab

Apply one or more filters to a raster image to remove extreme values or enhance linear features. When a filter is selected it is added to the Apply Order window. To change the order in which a filter is applied use the Up and Down arrow buttons. To remove a filter from the list, use the Remove Filter button. For selected filters a weighting or threshold value can be applied.


Sharpness Filters

• Smooth

Apply a mean smoothing filter over an image to reduce noise or high pixel values. Each pixel is replaced by the RGB mean values of the central and surrounding pixels using a 3x3 kernel. To increase smoothing, add a selected Smooth Weight value to the central pixel value.

• Sharpen

Enhance the difference between pixel colours by applying a 3x3 kernel with a high central value and zero and negative surrounding values. The degree of sharpening can be increased by adding a Sharpen Weight to the central kernel pixel.

• Gaussian Blur

Remove significant changes in colour in an image by graduating the colours of the intermediate pixels. A higher weighting is applied to the central pixel with less weighting given to surrounding pixels in the 3x3 kernel the further they are from the edge. To increase smoothing, add a selected Smooth Weight value to the central pixel value.

Edge Detect Filters

Enhance contrast in an image by applying one of the following edge detection filters:

• Quick

• Vertical

• Horizontal

• Sobel

• Prewitt

• Kirsh

The Quick filter applies a vertical and horizontal edge detection over an image and then merges the two resulting images together to create the final filtered image.


The Vertical and Horizontal filters are 3x7 and 7x3 kernels designed to enhance vertical and horizontally trending edges.

The Sobel, Prewitt and Kirsh filters are all horizontal filters which apply a negative weight along one edge of the 3x3 kernel and a positive weight on the other edge with the middle pixels with no or negative weighting (Kirsh). Using the difference between the central pixel value and its surrounding pixels in the kernel a Threshold Value can be applied whereby a pixel with a value less than the threshold will be assigned the threshold value. This enables greater contrast between edges by displaying below threshold pixels in the same colour.

Other Filters

• Mean Removal

This is another sharpen filter with a 3x3 kernel which filters in a diagonal direction as well as the horizontal and vertical direction. The degree of sharpening can be increased by adding a Mean Removal Weight to the central kernel pixel.

Clipping an Image

Images>Clip Image

Clip a raster image to a region such as a project area or tenement boundary. The clip object may designated by one or more polygon or rectangles in an existing table or the cosmetic layer. The clip object may also be a multi-polygon (one polygon which is comprised of two or more non-contiguous polygons). Two image clipping options are available:

• Clip Outside Polygon

• Clip Inside Polygon


Clip Image tab

Select the clipping polygon(s) table or map window selection from the Clip against Table pull-down list. Alternatively, choose the Custom rectangle drawn on preview option to define a clipping region over the image in the preview window with the cursor.

When an irregular shaped polygon is used as the clipping object the image is clipped to the minimum bounding rectangle of this region. This will result in a rectangular clipped grid with portions of the image masked along the polygon boundary. The colour of the mask can be selected from the Clip Colour palette. Use the Table>Raster>Adjust Image Styles menu option to make the selected mask colour transparent.

To determine whether a grid cell is to be included or excluded from a clipped image a Tolerance can be set. This value represents the portion of a grid cell in metres that needs to be inside or outside of the clipping region in order for it to be included in the clipped image.


Rotating an Image

Images>Rotate Image

To rotate an image, select one of the pre-set rotation options or Custom Rotation to manually select the desired rotation angle using the Rotation slider bar. Alternatively, select Custom Rotation and manually enter a rotation angle between 0 and 360.

Rotate Image tab

Converting an Image to Another Format

Images>Convert Image

Convert an existing raster image to another image format. By default a modified image is saved in the same format as the original raster image. A raster image can be converted to a PNG, JPG, JPEG, BMP, or TIF format.


Convert Image tab

Choose the desired raster format from the Convert image to pull-down list. If a JPEG format is selected use the Quality slider to determine the degree of compression in the output image. The lower the quality the more compressed the output image will be resulting in a loss of image detail.

If you wish to open the converted raster image in a third party software program that cannot read .TAB files then check the Create World File when Saving box. A world file is a six-line text header file that contains information relating to the image pixel size in X and Y direction, rotation of row or columns and the X and Y coordinates of the centre of the image top left pixel. Depending on the raster type selected for the registered raster image, a world file may have one of the following file extensions: .PGW, .JGW, .BPW or .TFW. Third party software programs can read and use this information along with an entered projection to view the raster image in the correct geographical location.

To create a world file for the image which is currently loaded in the Image Tools dialog, click on the Create World File For Current Image button. The world file is automatically created and saved to the same directory as the current image.


Modifying Image Transparency

Images>Modify Image

The Modify Image tab enables a transparency level to be set for an entire image or the selection of a single colour in the image to be set to transparent. Single colour transparency is generally used for images that are surrounded with coloured null areas that obscure underlying data layers when the image is added to a map window.

This tool does not alter the original image file. Transparency is only applied when displayed in MapInfo Proffesional via its TAB file.

Modify Image tab

To set image transparency:

1. Open the image into MapInfo.

2. Select Discover>Images menu.

3. Select Images>Modify Image.

4. Choose the image from the Select Image pull-down list if it is not already displayed.


5. Drag the slider to the desired transparency level between 0% (no transparency or opaque) to 100% (transparent or invisible).

6. Click OK to save the image.

To set a transparent colour:

1. Open the image into MapInfo.

2. Select Discover>Images menu.

3. Select Images>Modify Image.

4. Choose the image from the Select Image pull-down list if it is not already displayed.

5. Click on the arrow next to Transparent Colour and select from the colour palette. Click More Colours to enter specific RGB or HSL values to create a custom colour to make transparent.

6. Click OK to save the image.

Note Image transparency can also be modified using Table>Raster>Adjust Image Styles. It can also be adjusted under the Layer control or the Enhanced Layer control.

15 Working with Drillholes 439

15 Working with DrillholesEncom Discover provides a comprehensive environment for processing and visualising drillhole data. The Discover Drillholes module provides the following key features for processing and visualising drillhole data in vertical section and plan view:

• Drillhole Data Workflow

• Data Formats

• IImporting Drillhole Data from Other Drillhole Appliations

• Creating and Managing Drillhole Proje cts

• Creating Planar Sections and Plans

• Creating a Polyline Section

• Creating a Trench or Costean

• Managing Sections and Plans

• Displaying Downhole Data

• Displaying Downhole Logs

• Legend Edito r

• Adding Sections to a Layout

• Adding a Map Grid to Sections

• Creating a Section Collar Plan

• Interrogating Drillholes

• Digitizing Boundaries

• Calculating Sectional Resources

• Downhole Compositing

• Calculating 3D Coordinates

• Calculating Maximum and EOH Values


• Saving Display Settings

Drillhole Data Workflow

A drillhole dataset is typically constructed from a series of tables containing information such as drillhole collar location and geometry, downhole survey measurements, downhole geochemical, geological or geophysical data and/or other related information.

To create drillhole sections and plans use the following steps as a guide:

1. Format all drillhole data and import into MapInfo. File formats such as Access, Excel, and CSV should be first imported into MapInfo to create .TAB files (see Importing and Exporting and Data Formats).

2. Ensure the collar table is mappable using File>Create Points.

3. Create a new drillhole project and assign the correct table and columns as required (see Creating a New Drillhole Project).

4. Perform data validation to check for drillhole name mismatches, missing data, sample overlaps and end of hole depth discrepancies (Validating a Drillhole Database).

5. Create cross-sections using selected lines or drillhole selections (see Creating Planar Sections and Plans).

6. Create a collar plan (see Creating a Section Collar Plan).

7. Format and display downhole data on sections (see Displaying Downhole Data and Displaying Downhole Logs).

8. Add sections and plans to a layout window at the correct scale with section grids and title block ready for printing (see Adding a Map Grid to Sections and Adding Sections to a Layout).

9. Save project for future use (see Saving and Restoring Drillhole Sessions).

Data Formats

• Drillhole Data Formats

• Costean Data Formats


Drillhole Data Formats

The Drillholes module in Discover can use drillhole data captured in a number of different formats. Discover can use drillhole data stored in any database format that MapInfo can read, including Access and other ODBC linked databases. Discover does not need to make any alterations or additions to the source data.

When Discover generates a drillhole section, the 3D coordinates are automatically computed, which means it is not necessary to store these coordinates in the original data tables. This improves ease of use with Microsoft Access database tables and read-only tables (such as Excel spreadsheets). Changes to the collar coordinates or to the downhole surveys do not require downhole coordinates to be recalculated.

A requirement for each project table is that it must contain a Hole ID field, to act as the key to link the different tables. The following data tables can be used to define a drillhole project:

• Collar Table (mandatory)

• Downhole Survey Table (optional)

• Downhole Data Tables (optional)

• Grid and Contour Surfaces (optional)

• Surface Geology (optional)

Collar Table

The collar location table is a mappable table (use MapInfo Table>Create Points) containing point objects for each drillhole collar. The collar table must include the following columns:

Note An exception to this rule is when the downhole tables including the survey are desurveyed using the Calculating 3D Coordinates tool. Full write access is required to create the relevant fields in the table—a native MapInfo table format is mandatory under this circumstance.

Note The field name and order of the mandatory columns is not important. These columns are specified during project setup.


HoleIDEastingNorthingElevationTotal DepthAzimuth (Optional)Dip (Optional)

If a separate downhole survey table is not present, the collar table must contain two additional numeric columns for the drillhole collar; Azimuth and Dip. Dips can be expressed as positive or negative values, e.g. -90° or 90°, and are measured from the horizontal: a 0 degree dip represents a horizontal hole, and 90 or -90 will result in a vertical drillhole.

All mandatory columns must be numeric, aside from the HoleID which can be a text field. For native MapInfo tables it is recommended that coordinates are stored in columns with a Float (Floating Decimal) data type.

Downhole Survey Table

The downhole survey table is an optional, non-mappable table that contains a list of downhole depth, dip and azimuth inflections for each drillhole; for example, as measured with a downhole survey camera. The table must contain the following columns:

HoleIDDepth AzimuthDip

All mandatory columns must be numeric, aside from the HoleID which can be a text field. Depth, Azimuth and Dip columns must be numeric; dip values can be positive or negative.

Note The field name and order of the mandatory columns is not important; the columns are specified during project setup.

Note Drillholes with no downhole survey table are displayed as straight lines using the Dip, Azimuth and Total Depth values from the Collar table.


Downhole Data Tables

Downhole data tables are optional, non-mappable tables that can contain sampled and logged interval information such as geochemical, geological or geophysical data values. A drillhole project can contain multiple downhole data tables. Downhole data tables must contain the following columns:

HoleIDDepth FromDepth To

All mandatory columns must be numeric aside from the HoleID which can be a text field. Depth From and Depth To columns must be numeric. The position and data type of the mandatory columns must be the same in each downhole data table. Other data columns such as sample number, rock type, gold grades etc can be present if required.

Sample intervals must not overlap within a downhole data table: see Validating a Drillhole Database.

Geophysical point measurements (e.g. magnetic susceptibility) must have the same From and To values to plot correctly. For example magnetic susceptibility readings taken at 38m, 39m & 40m will have the following format:

An example of a geophysical (point sample) downhole data table: the From and To fields must be identical for each measurement

Note The field name of the mandatory columns is not important; the columns are specified during project setup.

Note The Collars, Surveys, Assays, Samples and Lithology tables in the .\Discover_Tutorial\Drillholes folder can be used as a template to create tables for use in a drillhole project.


Grid and Contour Surfaces

Discover can extract sectional profile information from gridded and contoured surfaces (such as surface topography, soil geochemistry or pit profiles) to display in the drillhole section. The Topographic surface can also used to extract elevation values for a Costean Collar and Survey tables.

A surface grid can be in any grid format supported by Discover such as ER Mapper, Surfer or Geosoft format. Contour maps must have polylines, polygons or points with the appropriate numerical attribute. See Supported Grid Formats for more information.

Surface Geology

Mappable table containing attributed polygons such as surface geology or regotlith. The polygons are draped over the topographic profile (if displayed) in cross-section displays. The polygon surface table is optional.

Costean Data Formats

The data tables required to create trench/costean views are very similar to those required for drillholes:

• Costean Collar Tables (compulsory)

• Costean Survey Tables (optional)

• Costean Downhole DataTables (optional - shared with Drillholes)

• Costean Grid and Contour Surfaces (optional - shared with Drillholes)

Costean Collar Tables

The trench collar file must be mappable (as with drillhole collar files) using the MapInfo Table>Create Points option, and requires the following fields:

• Trench ID

• Easting

• Northing

• Elevation (optional)

• Bearing (not required if a survey table is present)


• Total Length (not required if an XYZ survey table is used; see below)

The Elevation field can be populated with the collar RL, or alternatively elevation data can be automatically captured by the Trenching tool from a topographic grid file associated with the drillhole project (see Creating a New Drillhole Project). If neither is present, it will default to a constant elevatlion of zero.

The Bearing field is compulsory if no survey table is present (i.e. for a straight trench). It is not required if an XYZ survey table is used. If a Bearing and Distance survey table is used, it is optional (the collar bearing could be incorporated into either the collar file or the survey file).

Costean Survey Tables

If the trench is non-linear i.e. it has a number of azimuth changes/inflexions along its length, a survey table is required. This requires a Trench ID field matching that in the Costean Collar Table.

The survey table can have two formats:

• XYZThe survey table contains the following additional compulsory fields listing the locations of inflexion points along the trench. This table must include the trench endpoint X/Y coordinates.

• Trench ID

• Order

• X (easting)

• Y (northing)

• Z (elevation) (optional)

The Order field requires numeric values that list/control the order of the survey points: for example, 1, 2, 3, 4… An excellent alternative is to use a cumulative trench length field (equivalent to a drillhole survey depth field): for example with values of 0, 22.5, 65, 89.1, etc.

Elevation data can either be supplied in a Z field, or z values can be captured from a topographic grid associated with the drillhole project at each defined survey point (by setting the Elevation pull-down to None: (Zero based or topo grid)).


An example of XYZ trench collar and survey tables. These include elevation data (but if this information is not present, a DEM grid could be utilized). RP0132 has one inflexion point, whilst RP0133 is a straight trench. Note the Order field in the survey file stipulating the order in which the inflexion points are handled: a cumulative trench length field could just as easily be used.

• Bearing and DistanceTrench inflexion points are listed, with the following compulsory fields types:

• Trench ID

• Order (not required if distance is Cumulative)

• Bearing (Azimuth)

• Distance (Depth)

Note If an XYZ survey table is used, both the Total Length and Bearing fields in the Collar table are not required (and will be ignored if specified).

Note The Z specification can be different to that in the collar file; it is possible to assign a Z field in the collar file, whilst Z values in the survey table setup are captured from a DEM grid file (or vice versa). If XYZ information for the collar itself is specified in both the collar and survey files, the survey file information will be utilized preferentially.


• Inclination (Dip - optional)

The Order field requires numeric values that list/control the order of the survey points: for example, 1, 2, 3, 4… An excellent alternative is to use a cumulative trench length field (equivalent to a drillhole survey depth field): for example with values of 0, 22.5, 65, 89, etc.

The Distance field is handled as either Cumulative or Segments values using the options at the bottom of the Costean Location tab:

• Cumulative: the total distance the Bearing measurement point is from the trench origin (not just from the previous inflexion/survey point).

• Segments: the distance of the Bearing measurement point from the previous inflexion/survey point (not the distance from the first point or collar).

The Inclination field allows a dip value to be specified for each section of the trench in tandem with a bearing. If no inclination/dip field is available, set this to None (Flat). The Trenching tool will assume that the trench trace is horizontal. Negative values are downwards dip (declining), and positive values are upwards dip (inclining).

Note If a Bearing and Distance Survey table is used, the initial trench azimuth can be specified either in the collar file or in the survey file (with a Distance of 0).

Note RL/elevation data will only be captured for each measurement point in a Costean Survey table, as well as the Costean collar location. This may be insufficient for regions of undulating topography; trenches composed of solely a start and end point will not follow the topographic profile. To rectify this, assign extra survey points to increase the frequency of elevation measurements.


An example of Bearing and Distance trench collar and survey files. Note that trench MCS0025 will plot as a linear horizontal costean as it has no survey information. Also, there is no elevation information in the collar file, thus collar elevation data will need to be automatically captured from a DEM grid associated with the drillhole project. The Distance field in the Survey file will need to be set as a Cumulative distance.

Costean Downhole DataTables

Trench data such as assay, magnetic susceptibility and lithological data need to be in the same table format as required for drillholes. They are also shared between both Drillholes and Costeans, such that a Downhole table can contain data for both Drillholes and Trenches. They require the following fields:

• Trench ID (matching those in the collar and survey tables)

• From

• To

• Fields for each data type (e.g. Cu and Au assays, or a Lithology field).

As with drillholes, the order and positioning of the TrenchID, From and To fields must be identical for all downhole data tables associated with the drillhole project, as these fields are assigned only once, and are therefore assumed to have the same position for all tables.


An example of a trench assay table.

Interval data (e.g. composite chip samples, lithological units) must have a To value greater than or equal to the From value. The trenching tool (as with the drillhole module) cannot handle overlapping downhole data intervals within the same field (e.g. zinc chip samples over the intervals of 121-125m and 124-130m in the same trench will cause display errors). Geophysical point measurements (e.g. magnetic susceptibility) must have the same From and To values to plot correctly. For example magnetic susceptibility readings taken at 38m, 39m & 40m will have the following format:

An example of a geophysical (point sample) downhole data table: the From and To fields must be identical for each measurement

Costean Grid and Contour Surfaces

As indicated previously in the collar and survey sections, elevation data for trench “collar” points as well as any inflexion points can be captured from a topographic grid associated with the drillhole project (as opposed to having elevation data supplied in RL/Z fields in the collar and/or survey files).


Importing Drillhole Data from Other Drillhole Appliations

Discover provides specialised tools for importing data from the gINT and WinLoG borehole logging applications, which automatically build a Discover drillhole project during the import process.

Additionally, you can import drillhole datasets from other databases or formats using the extensive array of import tools available, and manually build the drillhole project as required. You can also import a wide variety of surface grids, raster images, and other spatial data.

For information on importing and exporting data for drillhole projects, see Importing and Exporting.

Creating and Managing Drillhole Proje cts

Drillhole projects are created and managed from the Drillhole Project Manager and other tools on the Drillholes menu:

• Creating a New Drillhole Project

• Validating a Drillhole Database

• Modifying and Deleting Drillhole Projects

• Assigning Costean/Trench Tables to the Project

• Opening Drillhole Projects

• Saving and Restoring Drillhole Sessions

• Creating a Subset of a Project

• Sharing and Packaging Drillhole Projects

Creating a New Drillhole Project

Drillholes>Project Manager

When creating a drillhole project, a wizard style interface assists in the correct data entry. The steps listed below provide an easy to follow guide to create a drillhole project.


1. On the Drillholes menu, click Project Manager, and, on the Project Manager dialog box, click New.

Drillhole Setup dialog.

2. To create a drillhole project enter an appropriate Project Name and Description on the Drillhole Project Setup dialog.

A Path to the project directory is mandatory, select the browse button and navigate to the respective folder where all the drillhole tables reside. The project path will be the location where drill sections, plans and log displays will be saved. Click OK to accept project path.


Browse for drillhole project folder.

3. Before selecting the tables to participate in the drillhole project, the Project Type and Section Manager options need to be specified.

Two options exist for the Project Type:

• Project only contains drillholes will display a wizard for drillhole data only.

• Project contains drillholes and costeans/trenches will display a wizard for drillhole data and costeans/trenches.


Costeans can be added removed from any existing Drillhole project by modifying the project. Costeans require a drillhole collar table to exist, as well as the costean collars table. The drillhole collar table can be a duplicate of the costean collar table. See Creating a Trench or Costean for more information.

When drillhole sections are generated, options are available to determine where the sections are saved and in the format. When the check Add New Sections to Section Manager is selected, any drillholes created will be saved automatically into the Project Definition Path e.g. C:\Encom Training\Drilling.

Two options exist for the Section Manager:

• Add Section to Project Root Directory will save all associated section files directly into the Project Definition Path e.g. C:\Encom Training\Drilling.

• Create New Directory for each Section will save a new folder for each individual section with all associated files into the default Project Definition Path e.g. C:\Encom Training\Drilling\Section1.

Section Manager options are global and not project specific. A change will affect all new sections for any project.


Drillhole Project Setup General dialog.

4. Select Next to specify collar tables to include in the project.

• Select the correct field mappings for the collar table and/or survey table.

When a mandatory field has not been defined or populated an attention symbol will appear next to the relevant field. Progression to the next dialog will not proceed until the correction has been made.

• With no MapInfo tables currently open navigate to the Open Tables button to open the collar table and/or survey tables.


• Select the correct unit increment for the collar and/or survey table. The Depth Units are the units of measure for the Total Depth and Depth fields e.g. m

Drillhole Project Setup Drillhole Location dialog.

5. Select Next to specify downhole tables to include in project.

• Select the Check dip fields orientation button to automatically assign the down dip to the appropriate convention.

Note If both negative and positive dips are encountered, the user will need to configure the Down Dip is negative option manually.

• Navigate to the Open Tables button to open the downhole data tables. Select the correct filed mappings.


Drillhole Project Setup Downhole dialog.

6. Select Next to specify surface or polygon tables to include in project.

Note During the drillhole project setup the mandatory columns are assigned using the first downhole table selected. If the mandatory columns in other downhole data tables are in a different column position, incorrect data may appear on the drillhole sections or plans.

• Navigate to the Open Tables button to open the surface and polygon tables if required.

• Select the correct field mappings.


Topographic Surface – Topographic gridded surface or contour table used to construct the sectional profile surface. Contours must have a numeric column containing the Z-value attribute. If a topography surface table is not specified, a surface profile can be generated by joining the drill collars together.

Polygon Drape – To display a surface geology or regolith layer, an appropriate surface file must be defined in the project. A gridded DEM surface provides the best surface profile however attributed contour data can also be used. When using contour data the surface geology (or polygon) layer is only shown in the area covered by the contour data. Discover does not extrapolate data outside the limits of the topography surface.

Other grid surfaces or contours – Other grid or contour surfaces such as base of weathering, pit profile or soil geochemistry can be displayed in profile in the cross-section.


Drillhole Project Setup Surfaces dialog.

7. Select OK to complete the configuration of the drillhole project.

8. Select Drillhole Project and OK on the Drillhole Setup dialog to open the project. All relevant project tables will be opened ready for sectional creation and analysis.


Drillhole Setup dialog.

Validating a Drillhole Database

Drillholes>Validate Drillhole Database

Discover includes a number of options to assist in validating the data used in a drillhole project. Using the data validation options can highlight data which can cause problems when creating drillhole sections and plans. Some of the main sources of the failure to plot all downhole data successfully on a section can be attributed to drillhole name or total depth mismatches and overlapping sample intervals within the collar and downhole data tables.

Note Upon completion of the Drillhole Project Setup or after the addition/update of any drillhole project tables, it is strongly recommended to validate the drillhole project (see Validating a Drillhole Database).


Drillhole Selection dialog.

The validation procedure may be run on the entire project database tables, selected drillholes in the collar map window or by the manual selection of drillholes to validate from the project drillhole list.

Data validation results may be printed to the screen and/or written to a log text file.

Data Validation dialog.


Discover provides the following validation options to identify a number of common data problems:

• Drillhole name mismatch – Common problems occur where the drillhole name is specified differently in the collar table and the downhole tables (e.g. DDH007 and DDH7 are considered by Discover to be different drillholes).

Drillhole project files linked to Excel spreadsheets may contain spaces before or after entries causing drillhole name mismatches.

• Total depth mismatch – If downhole data exists below the total depth specified in the collar table it will not be displayed in section. This can occur due to data entry errors or if the collar data was entered before the drilling was complete.

• Large Dip/Azimuth changes – Data entry errors in either collar table dip/azimuth measurements or downhole survey readings can cause significant problems that are difficult to pick up. Discover lists all drillhole surveys where the drill trace deviates by more than a specified amount between surveys.

• Duplicate sample numbers – In some instances duplicate sample numbers are an indication of data entry errors and need to be identified.

• Overlapping sample intervals – Sample intervals should not overlap in the same downhole data table and any such intervals must be identified and resolved.

• Sample interval gaps – Although many drillholes do not have contiguous sample intervals from top to bottom, it is often very useful to list out where the gaps are located to ensure these are not attributed to data entry errors.

Modifying Invalid Data

Numerous tools are available in MapInfo and Discover to rectify invalid drillhole datasets. An example of rectifying invalid data in a lithology table is displayed in the following example.

1. After performing a validation routine from the Drillhole module, a series of Browser windows displaying the invalid records are presented; along with a Message dialog identifying the invalid data records.


Error Browsers and Message dialos displaying invalid drillhole data records. Data validation issues can be observed in the drillholes MS2, MS9 and MS13.

2. The Error Browser Windows display records containing invalid data, it is a good practice to interrogate a couple of records surrounding the invalid data to obtain a full understanding of the invalid data.

3. Query the entire drillhole with the Discover>Data Utilities>Select By Group tool, select the table initially checked for validation e.g. DH_Lithology. From the Message dialog, the primary invalid data to investigate are the overlapping sample intervals. Select the drillhole containing overlaps e.g. MS2. Specify a query name for the selection e.g. MS2_Overlap for easier identification.


Query invalid drillhole with Select By Group dialog.

4. The Browser Window query displays the entire drillhole containing invalid data. The provided example displays a typographic error which has caused the validation issue. Modify the value contained in the ‘From’ field from 60.8 to 68 and save the lithology table with the File>Save Table command.


MS2_Overlap Browser displaying overlap entries.

MS2_Overlap Browser displaying overlap entries rectified.

5. Perform the drillhole validation on the original lithology table to confirm the invalid data entries have been rectified. Validate all remaining downhole tables following this process.

Modifying and Deleting Drillhole Projects


Use the Drillhole Project Manager to open, modify and delete existing drillhole projects.

1. On the Drillholes menu, click Project Manager.

2. Click the Select Drillhole Project box and select the project, and then:

• To open the project, click OK, and then use the Section Manager (see Managing Sections and Plans) to view sections and plans defined in the project.


• To add or remove tables and modify the project settings, click Modify.

• To delete the project, click Delete. The project tables and sections are preserved - only the project references are removed.

Alternatively, you can restore a saved drillhole session with the Drillholes>Project Session tool (see Saving and Restoring Drillhole Sessions). This will load the drillhole project and any ancillary components such as layouts , legends, titleblocks, open section and plan windows. This is a recommended way of preserving sessions incoporating layout windows.

Assigning Costean/Trench Tables to the Project

To generate a trench/costean section or plan, the relevant costean tables need to be associated with a drillhole project. A drillhole project requires at least a Drillhole collar table, in addition to the Costean Collar table. This will generally be an existing Drillhole Collar file; however, a copy of the Costean Collar file can be created and used as the Drillhole collars if there are no drillholes associated with the project.

Costean collar and survey tables are assigned to any existing drillhole project from the Project Setup menu.

1. Open the Project Setup dialog and select the Modify button.

2. Open the collar and/or survey table by using the Open Tables button on the bottom of the Drillhole Project Setup dialog.

Note Because of the metadata links created in drillhole projects, you cannot reopen a drillhole project using a MapInfo Professional workspace.


The Trenching Setup dialog configured for a XYZ survey table. If a section is generated, the trench trace will be initiated 1.5m below the surface RL at the collar location, due to the assigned Offset Z value.

3. Select the collar table from pull-down list. Set the various required and optional fields in the Field Mappings, as detailed in the Apply Downhole Trench Data section.

4. Select the survey table from pull-down list. Tick either the XYZ or Bearing & Distance format option as detailed in the Costean Survey Tables section, and set the required Field Mappings.


5. For both the collar and survey tables, if elevation data is to be captured from a DEM/DTM, set the appropriate fields to “None: (Zero based or topo grid)” rather than the collar Elevation field.

6. An offset z value can be specified as a (negative) value below the surface at which the trench trace will be plotted in section views. This is appropriate when assay samples have been collected a constant depth below surface e.g. 1.5m. The units used will be those specified in the Project Setup dialog on the Drillhole Location tab.

If downhole trench data tables and/or a topography grid needs to be added to the project continue with the next section, otherwise press OK to complete the trench setup.

7. To add downhole trench data navigate to the Downhole tab on the Drillhole Project Setup dialog and open the respective assay, lithology etc tables using the Open Tables button. Populate the Selected window pane with these tables by highlighting them and using the Right arrow button.


Assigning the trench downhole data tables (in this case assay and lithology tables).

8. To add a topographic gridded surface, navigate to the Surfaces tab on the Drillhole Project Setup dialog and open the grid using the Open Tables button. Select the grid under the Topographic Surface option.


Assign topographic surface to drillhole project.

Press OK to complete the setup of trench data.

Opening Drillhole Projects


The recommended method of opening drillhole projects is to restore a saved drillhole session with the Drillholes>Project Session tool (see Saving and Restoring Drillhole Sessions). This will load the drillhole project and all layouts, legends, title blocks, sections and plan windows saved with the session.


You can also open projects from the Project Manager:

1. On the Drillholes menu, click Project Manager.

2. Click the Select Drillhole Project box and select the project, and then click OK.

3. Use the Section Manager to view sections and plans defined in the project.

Saving and Restoring Drillhole Sessions

Drillholes>Project Session>Save SessionDrillholes>Project Session>Load Session

Discover drillhole projects cannot be simply saved and reopened as MapInfo Professional workspaces, due to the various complex metadata links handled by the Drillhole Module between the project datasets (such as the field assignments in the survey, collar and downhole data tables).

Instead, the current open drillhole project, including any open layout windows, titleblocks, associated section and plan map and browser windows, etc, can be saved as a Project Session using the Drillholes>Project Session>Save Session menu option. This will create a .dwor file with the specified Name in a new ‘Sessions’ subdirectory under the current drillhole project data folder. Descriptive and comment fields can also be saved in this session file.

Existing session files can be loaded using the Drillholes>Project Session>Load Session menu option. Selecting a drillhole project will list any associated sessions; each session’s information (description and comments) can be examined prior to loading. Upon pressing OK, the drillhole project will be opened as well as any ancillary components (layout windows, titleblocks, legends, section windows, etc) saved with the session. This is an alternative method of opening a project to using the Project Manager.

All existing open tables within MapInfo Pro must be closed before the Load Session dialog can load. Make sure to save any cosmetic layer objects permanently with Map>Cosmetic Objects before using the tool.

Note You cannot reopen a drillhole project using a MapInfo Professional workspace.

Note Project Sessions are not supported by the Drillholes Import/Export tools.


Creating a Subset of a Project

Drillholes>Subset Project

The Subset Project tool allows an existing open drillhole project to be subsetted based on a selection of drillholes. This will create copies of all the relevant drillhole tables (collar, survey, downhole data, topography, etc) subsetted to the drillhole selection, automatically creating a new drillhole project using these new tables.

The Subset Drillhole Project dialog.

The Subset Drillhole Project dialog displays a list of the open project’s drillholes, with the current selection highlighted. Holes can be selected manually from this list (use the CTRL keyboard button in combination with the left mouse button to select non-adjacent holes). Alternatively a selection can be made in MapInfo prior to opening this dialog, using tools such as graphical selection, an SQL query or the Discover>Data Utilities>Select by Group option(see Select by Group). This selection will then be automatically highlighted when the Subset Drillhole Project dialog is opened.


A new Drillhole Project will be automatically created by adding a “_Subset” suffix to the current project’s name; this name will be also be used to create a new subdirectory under the current Project directory, into which the subsetted tables will be placed. This New Project Name can be changed in the appropriate window; the tool will automatically alter the output directory name, which can also be manually specified using the browse button. A “_subset” suffix is also attached by default to the subsetted output tables; this can also be altered in the Suffix to append to tables window.

The Optional Files list allows selection of project files to incorporate into the new project (by default all tables are selected). For example, if the current project included 10 downhole data tables, this option could be used to select only three tables of interest. If a survey table is associated with the current project, it is recommended to ensure that this is selected.

Note: Grid and Image files associated with the current project will not be subsetted, but simply copied in their entirety to the output directory with the “_subset” (or other user-defined) suffix attached.

Once this dialog has been configured, press the Subset button. When completed, a text report will be displayed detailing each table created and any issues that may have arisen.

The Subset Project Report indicating the success of each table subset.

Sharing and Packaging Drillhole Projects

Drillhole projects can be imported and exported to allow transfer of projects to other computers or for archiving of projects. This process supports not only the project source data, sections and plans, but also the all metadata required to automatically reopen the porject on the destination camputer. See (importing and exporting) Discover Drillhole Projects.


Creating Planar Sections and Plans

Drillholes>Define New Section or Plan

A cross-section can be generated for a vertical plane at any location and in any orientation. A plan may be generated for a horizontal plane at any elevation. To generate a section from a non-linear section or “fence” defined by a polyline, see Creating a Polyline Section.

A section or plan is defined in the Drillhole Plotting dialog. All the parameters for selecting the drillholes to plot, the downhole data tables to use, displaying other grid surfaces, annotating with collar name and depth ticks, drawing topographic profiles, creating multiple sections and applying downhole display settings are available in this dialog.

Select the type of Drillhole Display, either Vertical Section or Horizontal Plan.

When a drillhole project is opened Discover will open a map of the collar table to enable a section or plan to be defined.


Vertical Section

Defining a cross-section to be displayed.

The first step in creating a drillhole vertical cross-section is to determine which drillholes are to be included in the section. The Hole Selection by control contains the following drillhole selection options:

• Manually Select - manually pre-select all of the drillholes to include in the section. In this case, the entire length of each selected drillhole is displayed and the section envelope width is not used. This option is the only drillhole selection option available for plans. All the Section Definition parameters apart from Envelope Width must be entered manually.

• Specify section – default option that selects all drillholes that lie within a section envelope. All the Section Definition Parameters must be entered manually.


• Use Selected Line – create a section envelope whose axis is defined by a selected line in the map window. This line must be a straight line containing a maximum of two nodes (start and end). The line must be selected in the map window prior to selecting the Define New Section or Plan menu item otherwise the Use Selected Line option will be disabled. This option will automatically populate the Section Start E and N and Orientation values from the selected line: the user must specify an Envelope Width, which represents the distance either side of the selected line that the envelope encompasses. See Section Definition Parameters.

Check the Search all Holes box to include in the section any drillholes that are collared outside the specified section envelope but intersect the section envelope at depth. This option is unavailable for plans.

Use a selected line to define drillhole section.

Previewing the Section Envelope

Select this button from the bottom of the dialog once all Section Definition Parameters and Display Options have been set. A red rectangle will be added into the cosmetic layer in the collar map window: this represents the extents of the specified section envelope. Additionally, all drillholes within this envelope will be selected/highlighted.

The section envelope (and the collars contained within this envelope) specified using either the Specify Section or Use Selected Line options can be visualized and altered prior to final section creation using the Refine button.


If the displayed envelope extents are unsatisfactory (e.g. too small or too large), simply rerun the Define New Section or Plan option, and respecify the relevant parameters (e.g. the Envelope Width). Note that if using the Use Selected Line option, the user will need to reselect the line before rerunning the Define New Section or Plan option.

The user can also add or remove collars to/from those selected in the collar map window. Hold down the SHIFT button and select/deselect the respective collars (the cosmetic layer will need to first be turned off to allow collar selection). Only collars in the section envelope can be selected. This is an excellent way of producing sections with defined envelopes using only RC collars in a project of mixed drillhole types (e.g. RAB, RC and DDH).

Once the displayed envelope is acceptable, and/or the required drillholes selected/deselected, finalize the section creation process by selecting the Drillholes>Plot Section or Plan menu option.

Section Definition Parameters

When using a selected line, the section start is automatically populated and the section orientation taken from the direction in which the line was drawn. The section length and envelope width can be altered in the Section Definition parameters. For the other drillhole selection options the section start coordinates, orientation and length must be entered manually.

The Envelope Width is a distance in metres specified from the section line. For example, an envelope width of 50m will extend the section area 50m either side of the section line to create a drillhole section 100m wide. When creating a section Discover will include any drillholes that are collared within the envelope width area along with any drillholes that intersect the section envelope at depth if the Search all holes box is checked.

The View Direction determines the direction from which the section is to be viewed. The view direction is automatically calculated by Discover based on the selected line orientation or from the section definition parameters. Section view orientations can only be set at +/- 90 degrees of the section line orientation. This enables the section to be viewed from either side.

A Section Name must be entered for each drillhole section. If a selected line is used, the Section Name is automatically populated with the Northing for E-W or oblique sections or the Easting for N-S sections (e.g. N8475292). These section names can be overwritten with any user-defined section name.

Note Automatically named sections can be renamed after they have been created using the Section Manager Rename function.


Horizontal Plan

Creating horizontal drill section.

To generate a horizontal or flitch plan of drillhole collars, firstly select the drillholes to include in the plan. Collars can be selected either graphically from the map window or via a query (e.g. an SQL query of all RC drillholes, or using Data Utilities>Select by Group). Then select Drillholes>Define Section or Plan and choose Horizontal Plan.


Plan Definition Parameters

A horizontal plan may be generated for all selected drillholes with no elevation limits. The entire length of each selected collar will be displayed on the horizontal plan. By default the Plot Survey traces only box is checked. This is to reduce the processing time for large downhole datasets if no downhole data is to be displayed along the drillhole traces. If downhole data is to be displayed on the horizontal plan uncheck the Plot survey traces only box.

Check the Use elevation range box to generate horizontal level or flitch plans at specified elevations. Enter a Central Elevation in metres and an Envelope Width. The Envelope Width is the distance in metres above and below the specified elevation. For example, an envelope width of 50m will extend the section area 50m above and below the specified elevation to create a horizontal section 100m wide. The elevation plan will display only the portion of any drillholes that are intersected by the horizontal section envelope.

Enter a Plan Name for the horizontal section.

Display Options

• Downhole Data

• Surfaces

• Annotation

• Multiple Sections

Downhole Data

If downhole data is to be displayed graphically in your sections or plans as linegraphs, histograms, etc., the data must be assigned during section or plan generation. By default, all downhole data tables configured during the Drillhole Project Setup will be automatically listed as Selected data to display on the Downhole Data Selection dialog box.

There may be instances where a drillhole project contains multiple downhole tables but not all the data tables are required for each section. Use the Add and Remove buttons to make sure only the required downhole tables are selected. The selected downhole data tables are retained from one section to the next.


During the creation of a section or plan, the selected downhole data for any drillholes present is extracted and incorporated into new section-specific MapInfo tables. These created tables are then used by Discover to display downhole data. Therefore data from a new downhole table added to a drillhole project after a section or plan has been created cannot be displayed.

Select downhole data table to be included in section creation.

Surfaces

Define surface parameters for display in section.

Any surfaces included in the drillhole project as Other Surfaces during setup, such as pit profile, weathering profiles, geochemical or geophysical surveys, will be listed under Available Surfaces. Use the Add button to move a surface to the Surfaces selected to display list. Highlight each surface in this list and choose the appropriate Surface Display Settings.


For each surface that is selected, the profile of the surface is displayed where it intercepts the section plane. The position of the surface profile may be Absolute or Relative. If the surface measures real elevation (e.g., proposed pit plan or depth of weathering) then the profile position is Absolute with no scaling or offsets other than the same vertical exaggeration as the section.

If the profile surface is not in elevation units (e.g., a geochemical or geophysical grid) then Relative position should be selected. The relative positioning and scaling can be determined automatically or the offset and scale can be specified explicitly. This method of surface profile placement is the same as used in the Surfaces>Draw Grid Profile function.

When the position, offset and scaling has been determined use the Accept Settings button to confirm. Note that for multiple surfaces the Accept Settings button must be applied for each surface.

Annotation

The Annotation options control the appearance of the section or plan. Available annotation options include:

• Preferred Scale - scale at which the section is to be viewed or plotted. Text label sizes and other annotation are relative to this scale. Base of hole symbols are taken from a TrueType font file shipped with Discover and so appear at the same size regardless of the Map Window zoom width.

• Vertical Exaggeration - provides control over the vertical scale with larger values giving greater exaggeration and a value of 1 giving no exaggeration.

• Drillhole Labels – display Hole ID labels at collar or EOH or EOH labels showing maximum depth and tick. The size of the labels is controlled by the Label font size and label style by the Default Text Style.

• Display Surface Line - display a surface profile on the section. If a Topography surface was selected in the drillhole project setup then the surface line will be created from this surface or contour file. If no topography surface is available the surface line will be created by joining the drillhole collars together. The style of the surface line is controlled by the Surface line style button.

• Use Data Display Setting - apply a saved downhole data display setting including linegraphs, histograms and text labels to the drillholes at the time the section is generated. See Using Setting Templates for more information on data display settings.


• Depth Ticks - place a depth tick and a text label at nominated depths, e.g. every 10 metres down the hole. Only label selected depth ticks.

• Show distance behind/infront plane of section – display the offset of each drillhole collar from the section plane, i.e. distance behind (negative value) or in front of the section's vertical plane at that point.

Drillhole Display Annotation dialog.

Multiple Sections

Discover can generate multiple sections or level plans. Multiple sections are created parallel to the first specified section or elevation with an equal offset from one section to the next. By default, the offset distance = 2 x envelope width, such that section envelopes are adjacent to each other, thereby providing continuous non-overlapping coverage.

Enter the number of sections to generate up to a maximum of 20 and the offset in metres from the first section (the offset defaults to twice the envelope width specified for the first section). Choose a prefix to use in the naming convention from Easting, Northing, 1 – 20 or A to Z.


Create multiple sections.

Alternatively, select multiple section lines in the collar map window to plot at the same time. These section lines do not need to be parallel and are created using the section envelope width, view direction and section name specified in the Define Section or Plan dialog. Subsequent sections are named using a “1, 2, 3, etc” filename extension so it is important to enter a logical section name and not use the default easting or northing section name.

Creating a Polyline Section

Drillholes>Define New Polyline Section or Plan

The first step to create a polyline drillhole section is to determine which holes are to be included in the section and define the path of the polyline. To assist in this process the Define Polyline Section tool is equipped with an envelope preview.

Note Automatically named sections can be renamed after they have been created using the Section Manager Rename function.

When all settings and parameters have been modified press the Plot Now button to commence the creation of drillhole sections.

The Define New Polyline Section tool enables the creation of vertical drillhole sections along multi-noded polyline segments. This functionality is ideal for the hydrological, geological and environmental engineering industries, who often need to analyze data along non-linear sections such as pipe lines, roads, tunnels and subsurface palaeochannels or aquifers.

Note Polyline sections can only be generated from surveyed drill traces with a vertical dip e.g.-90 or 90. Drill traces with non-vertical dips will be ignored during section creation.


The steps listed below provide an easy to follow guide to create a polyline section.

1. On the Drillholes menu, click Define New Polyline Section. Within the collar mapper window either digitise and select a polyline to define the section path or select a pre-existing polyline object e.g. road traverse. Click the Get selected line properties button to retrieve the polyline properties.

2. With the line properties detected a section envelope will appear in the collar map window to assist in the creation of the vertical section.

Before a section can be created certain parameters will need to be analysed or modified within the Section Definition and are described below.

The Envelope Width is the distance unit either side of the section plane. For example an envelope of 100m will extend the envelope +/- 100 m either side of the section plane, therefore the section envelope total width will be 200m. Discover will include any collars in the section which are located in the envelope with a vertical dip. The section envelope will interactively change width in the map window when the envelope width value is modified.


The View Direction determines the direction from which the section is to be viewed. The view direction is automatically calculated by Discover based on the selected line orientation for the first polyline segment. Section view orientations can only be set at +/- 90 degrees of the section line orientation.

The Section Start E and Section Start N are the coordinates at surface where the section plane originates, and recorded automatically from a selected polyline.

Section Top defines the Reduced Level (RL) value for the vertical section. For example the default value is 0 for Section Top, this displays the vertical section Z values from the raw dataset uncorrected. If the centre of the section is 1000m RL, this be displayed on section. If a value of 1000 is entered into the Section Top then the centre point of the section will be 0m RL. If a value of -1000 is entered into the Section Top then the centre point of the section will be 2000m RL. The Section Top will apply an offset to the Z value, this is particularly useful when a section falls below 0m RL and you wish not to display negative values.

The Length is the length of the line which defines the section plane; this value is recorded automatically from a selected polyline.

3. Click on the Annotation button to display further Annotation Options for section display.


Available options include:

• The Prefered scale is the scale at which the section is to be viewed or plotted. Text label sizes and other annotations are relative to this scale.

• Vertical exaggeration provides control over the vertical scale with larger values giving greater exaggeration and a value of 1 giving no exaggeration.

• Label font style, Label font size and Label font colour are options which determine the appearance of section text.

• Other label options include Display Hole ID at Collar, Display Hole ID at EOH and Display EOH labels and ticks.

• The Display surface line enables the display of a surface profile on the section. If a topographic surface was selected in the drillhole project setup then the surface line will be created from this surface. If no topography surface is available the surface line will be created by joining the drillhole collars together. The style of the surface line is controlled by the surface line style button. If a geology polygon surface was selected in the drillhole project setup then the surface line will adopt the polygon colours.

• Options exist for the display of depth interval ticks. The Depth interval is the specified interval ticks will be placed on the downhole trace the depths ticks are independent to the sampling intervals in the downhole tables. Annotations for displaying the ticks labels are also available, including offset and number.

Click the OK button when satisfied with the selected annotation options.

4. Click on the OK buton on the Define Polyline Section dialog to proceed with the production of a polyline section.

Note Sections created using a polyline are not currently compatible with many Drillhole Module tools such as Create Section Collar Plan, Boundary Digitizing and Sectional Resource Calculator.


Creating a Trench or Costean

Drillholes>Define New Trench or Costean

The Drillhole module incorporates the ability to generate section and plan views of trenches (also known as costeans). Unlike drillholes, trenches do not require an algorithm (e.g. tangential averaging) to be applied to generate the trace; trench traces are generated by simply joining a number of survey points, whether these are XYZ locations or distance and bearing measurements. This is also an excellent way of displaying tunnel/drive wall data.

Note Trenches created using this tool can be controlled via the Display Downhole Data tool (see Apply Downhole Trench Data) in the same way as a drillhole section or plan. Trench assay and lithological data can be applied as “downhole” data. Shallow subsurface data can be correlated to drillhole derived data, allowing a more comprehensive interpretation to be made in plan and section views.

Note Trenches should not be plotted as Drillholes, as the Surveys and data are interpolated, and will plot inaccurately for Trench measurements.


A combined trench and drillhole section view.

Create Trench Display

To generate a trench plan or section, ensure the relevant drillhole project (to which the trench files have been associated) is open, and select the Drillholes>Define New Trench or Costean menu.

• Create Trench Plans

• Create Trench Sections

• View Definition

Create Trench Plans

With the Trenching dialog open select the Plan option, and highlight the trenches to plot from the list on the left of the dialog. The output plan name and file location can be changed using the Save button under Output Options. Press OK to generate the trench plan. This will be opened in a new mapper window.


Defining a trench plan for only the RP0133 trench.

Create Trench Sections

With the Trenching dialog open select the Section option, and highlight the trenches to plot from the list on the left of the dialog.

Two methods of trench section specification are available:

• Manual InputThis requires manual definition of the section origin X, Y & Z values, the section length and width, and the angle (azimuth) of the section. The section angle can be either entered as a numeric value, or set using the interactive compass.


• Selected LineThis requires a section definition line to be already selected in the trench collar map window (before the Trenching tool is opened). The only extra parameters required are the section envelope width and origin elevation. The section view orientation is governed by the line drawing direction; the section will be displayed left (start) to right (end).

View Definition

The Envelope Width is the distance unit either side of the section plane. For example an envelope of 100m will extend the envelope +/- 100 m either side of the section plane, therefore the section envelope total width will be 200m. Discover will include any trench traces in the section which are located in the envelope.

The Length is the length of the line which defines the section plane; this can be manually entered or recorded automatically from a selected line.

The Origin X and Origin Y are the coordinates at surface where the section plane originates from; these can be either manually entered or recorded automatically from a selected line.

Origin Z defines the Reduced Level (RL) value for the vertical section. For example the default value is 0 for Origin Z this displays the vertical section Z values from the raw dataset uncorrected. If the centre of the section is 1000m RL, this is what will be displayed on section. If a value of 1000 is entered into the Origin Z then the centre point of the section will be 0m RL. If a value of -1000 is entered into the Origin Z then the centre point of the section will be 2000m RL. The Origin Z will apply an offset to the Z value, this is particularly useful when a section falls below 0m RL and you wish not to display negative values.

The Angle defines the bearing of the section plane or selected line from grid north.

The View Direction determines the direction from which the section is to be viewed. The view direction is automatically calculated by Discover based on the selected line orientation or from the section definition parameters. Section view orientations can only be set at +/- 90 degrees of the section line orientation.


Defining a trench section using a selected line.

The trenching tool will generate section traces only for those portions of the selected trenches that intersect the defined section envelope. The output section name and file location can be changed using the Save button under Output Options. Press OK to generate the trench section. This will be opened in a new mapper window.

The Annotations button in the Trench dialog opens the Trench Annotation dialog. This contains options for displaying:

• the Trench ID as a collar label

• length ticks and labels; the distance between these can be set in the Length Interval window.

The font controls at the bottom of the dialog will apply to any annotations selected.


The Trench annotation dialog, incorporating display options for TrenchID and length ticks and labels.

Apply Downhole Trench Data

Downhole data (e.g. assays and lithological data) can be applied to trench cross-section or plan views in the same way as downhole drillhole data. With the relevant section or plan open, run the Drillholes>Display Downhole Data menu option.

For a full description on the use of this option, see the Displaying Downhole Data section.

Note The use of histograms and linegraph displays on trench plans with large azimuth changes at inflexion points is not recommended due to the potential for overlapping data displays between trench intervals.

Note Ensure that downhole trench data is associated with the drillhole project before generating trench plans or sections, otherwise this data will not be able to be displayed on the section/plan view.


Combine Drillhole and Trench Section Views

If adding a costean section to a drillhole section (or vice-versa), ensure the same section definition parameters are used, or same section definition line, to ensure the section views are spatially related. It is recommended to save section definition lines to a table (e.g. section_lines), and then reuse these to generate both drillhole and trench sections. Also ensure that the view directions of both sections are identical.

To add a trench section to a spatially related drillhole section window, ensure both sections are open, and make the drillhole section window the top-most map window. Using either the Layer Control or Enhanced Layer Control, use the Add Layer option to select all relevant trench section layers (e.g. sectionname_TrenchD, sectionname_TrenchA and possibly sectionname_Trench1, sectionname_Trench2, etc) and add them to the drillhole section mapper.

Using the Add Layer option of the Enhanced Layer Control to add trench section tables to a spatially related drillhole section map window.


Managing Sections and Plans

Drillholes>Section Manager

The Drillhole Section Manager enables the hassle free management of all associated MapInfo tables for drillhole project sections. All vertical sections, plans, polyline sections and costeans defeined in a project are listed in the Section Manager dialog.

Section Manager dialog.

From Section Manager dialog box, you can:

• Display Section Parameters

• Open Sections

• Refresh Downhole Data

• Regenerate Sections

• Rename a Section

The Drillholes Section Manager is designed to assist with the management of cross-sections and plans, including opening closing and renaming.


• Add a Section

• Close Sections

• Delete Sections

Display Section Parameters

The Section Manager displays numerous parameters for each section, including:

Section Type

Open

Open status of the drillhole section, open sections are marked with a tick.

Name

User specified name of the drillhole section

Orientation

Orientation or bearing of the drillhole section

Width (+/-units)

The Envelope width of the section. Note that the width is symmetric about the centre, and the total envelope width is twice the value displayed.

Easting

Start easting for the section line

Northing

Start northing for the section line

Vertical Drillhole Section

Vertical Drillhole Section with digitised boundary layer

Vertical Drillhole Section defined by polyline (non-linear)

Horizontal or Plan View Drillhole Section


Z

The maximum elevation in a Vertical cross-section, or the central elevation in a horizontal plan/section.

Length

Length or distance of the drillhole section line, the units of measure are determined by the collar table projection system.

By default when a drillhole section is created it will be catalogued into the Section Manager, with all the parameters automatically populated. An exception is the production of Horizontal or Plan view sections.

The most commonly used section manager tools are displayed directly on the dialog. The less commonly used functions are located under the More button, these include Rename, Refresh, Add and Delete.

Open Sections

Refresh Downhole Data

Note The parameters displayed in the Section Manager can be sorted by clicking the mouse cursor on the parameter header.

All sections and plans created for the drillhole project are listed in the Available Sections and Plans window. Select the section(s) to open and select the Open button to display previously created section(s) or plan(s). Alternatively, sections can be opened by double left mouse clicking on the desired section in the list.

Selected cross-section locations and envelopes can be displayed on the collar map window by clicking the Preview button on the Section Manager dialog.

Base data for a drillhole project can change over time. New assay results may be received or survey data updated. Instead of re-generating any section traces that have already been created, the Refresh button in the Section Manager can be used to update any drillhole sections or plans with the new data from the base tables.


This option does NOT automatically update any Display Downhole Data settings applied, just the section trace data (originally created with the ‘Define New Section or Plan’ option). The user will still need to reapply any downhole data display options to visualize the updated section display. For this reason it is always recommended to create and use the display settings described in Displaying Downhole Data to simplify the updating of sections.

Regenerate Sections

When the Preview option is selected in within the Section Manager dialog, the line used to originally generate a section is displayed in a temporary MapInfo table.

If the original linework to generate a series of sections has been deleted or never saved the temporary previewed table can be used for regeneration. To regenerate a section, ensure the Preview option is enabled and select the desired line for sectional regeneration.

Alternatively, the temporary table named _sectionPreviewOverlay can be saved as a permanent MapInfo table using the File>Save Copy As command within MapInfo.

It is strongly recommended that you save the linework table into the drillhole project directory for future reference.

Rename a Section

Note The Refresh option can only be used in instances where the depth intervals used in the creation of the original section remain the same. If the original depth intervals, downhole column names or column order are changed or new data columns added in the base table, the section or plan will need to be re-created. Sections or plans must also be re-created if new drillholes have been added to the collar table or a new downhole table is added to the drillhole project after the original section or plan was generated.

The Rename button will permit the renaming of a selected section including all component tables and metadata.


Rename section dialog.

Add a Section

Close Sections

Delete Sections

During the initial Drillhole Project Setup if the option for adding sections to the Section Manager was not selected, sections will need to be manually added to the Section manager. If a section has been created but not assigned to the Section Manager it can be added to the list of Available Sections for a project using the Add button. Highlight the section to add from the list of currently open sections in the Add Section to Section Manager window.

The Close button will close the selected section and plan tables.

The Delete button will permanently delete the selected section and plan tables from the Section Manager and the Windows project directory.

Note All sections and plans created for a drillhole project can be managed using the Section Manager. Refer to Creating and Managing Drillhole Proje cts section for Section Manager configuration.


Displaying Downhole Data

Drillholes>Display Downhole Data

A drillhole cross-section displaying geochemical assay values as both text labels and a histogram plot, as well as geology presented as a trace shade.

Once cross-sectional or plan traces have been created (Creating Planar Sections and Plans, Creating a Polyline Section, Creating a Trench or Costean), you will want to start visualising your downhole data graphically. This might include data such as assays, geology, regolith, geophysics, water table depths and structural measurements.

The Display Downhole Data tool allows these detailed downhole datasets to be effectively visualized (even in complex sections or plans) using a number of display types, including Text Labels, Histogram/Linegraph, Trace Shade and orientated Structure Ticks.

Additionally this tool can:

• Display up to 16 different data attributes (or variables) for each drillhole

• Display data from any appropriate column in any downhole data table

• Colour and pattern modulate display types with user-created legends


• Create editable data attribute legends

• Save your downhole display settings as templates. These can then be applied to new sections, or reapplied to the existing sections after the sections have been regenerated, or shared with other users.

The Downhole Data Display settings dialog.

To create a downhole display setting:

1. Open a drillhole project (see Opening Drillhole Projects), and open one or more cross-sections or plans (see Managing Sections and Plans)

2. Select the Drillholes>Display Downhole Data menu option to open the tool (or use the toolbar button).

3. Ensure that the Global Map Scale at the bottom of the dialog is set to the intended output scale. This will generally be the same as the Preferred Scale as set in the Define New Section or Plan tool under the Annotation button.

4. Choose a display type from the icons at the top of the dialog:

• Text Labels are excellent for displaying exact values or attribute codes, but can result in a cluttered view if over-used. Ideal for assays. These can be colour coded to help discern trends.


5. Upon pressing a display type's button, a new entry will be added to the spreadsheet in the main dialog with a representative icon, and a settings dialog will open.

6. In the settings dialog, select the source Table and Field to use for the display type, e.g. DH_geology and LithCode for trace shades, or Assays and Cu for a linegraph.

7. Each display type can be positioned precisely where the user wants it, either to the left or right of the drillhole trace. This is important to prevent different display types overprinting each other (e.g. multiple text labels). The Offset parameter in each setting dialog controls this positioning in millimetres:

• a negative offset value places the display type to the left of the hole trace

• a positive offset value positions it to the right

• The Set Offset button has a number of preset options to get you started (Near Left, Far Right, etc).

• Linegraph (Histogram/Linegraph) are an excellent way of visualising numeric datasets, particularly for identifying and assessing trends along and between drillholes and sections. They are very effective for high density downhole datasets such as decimetre- or even centimetre-scale geophysical measurements.

• Histogram (Histogram/Linegraph) are another excellent way of visualising numeric datasets. They clearly indicate both the sample interval widths, as well as the sample values (i.e. samples are represented discretely as individual 'bars'). Histograms (unlike linegraphs) can be colour and pattern modulated.

• Trace Shade are a powerful way of visualising attribute information, such as geology and regolith logging. These utilise custom colour legends to control the trace colour and/or pattern.

• Orientated Structure Ticks allow structural measurements such as bedding, foliation, veining, etc to be correctly displayed using either true or apparent dip directions. These can be colour modulated.

Note The offset of each display type can also be controlled in the main dialog by altering the values in the Offset column


8. Populate the remainder of the dialog as necessary: each display type's setting is discussed in relevant section below. All display types (except the Linegraph) can also be colour and/or pattern modulated using legends created using the Legend Edito r. Press OK when finished with the setting dialog.

9. Back in the main Downhole Data Display dialog, repeat steps 4-8 for each additional data field to be displayed.

10. Existing display types listed in the main dialog can be easily modified and edited:

11. Once satisfied with your display settings, it is worth saving this

Note Although up to 16 attributes may be displayed at the same time on a section or plan this may not be practical due to drillhole spacing or plot scale. To create a well-presented section map, limit the display to a suitable number of data attributes.

• To reopen an existing display type's settings for modification, click on the Settings button on it'd far right. Alternatively, double click in any static part of the row entry (e.g. the table or field cells)

• The listing order of display types can be rearranged by selecting a

row (click once in a static cell) and then use the reorder buttons . Note that this does not affect the actual display type offsets on the section/plan: it is only of use visually to reorder display types to match their offsets.

• Existing display types can be deleted from the listing by selecting one or more row entries (click once in a static cell; use in combination with SHIFT or CTRL for multiple selections) and pressing the delete button

• The Offset of each display entry can be altered from the listing by modifying the values in the Offset column. This is a powerful way of 'tweaking' display positioning to prevent overlaps, practically once the listings have been reordered (i.e. from -ve to +ve offsets).

Save display settings as a Setting Template (see Using Setting Templates). Press the Save Downhole Settings button, enter an appropriate name (typically project-specific) and press OK. This ensures that your customised settings can be reused or modified at a later date.


• the number of sections/plans selected

• the number of drillholes in the sections/plans

• the length of the drillholes

• the number of display settings selected

• the size of the sample intervals (1m assays decimetre-scale geophysics measurements)

• text labels are significantly slower to render than other display types

13. Once the section/plan has been rendered, zoom and pan within its map window to check offsets, scaling, text sizes, etc. If any issues are apparent, simply modify the necessary parameters in the still open Display Data Display dialog (either in the main display listing, or in individual settings dialogs). Then resave the setting template (e.g. overwrite the previously saved tempate), and reapply to the target section.

12. In the Sections listing on the right of the main dialog, highlight a section to apply your display settings to. Before continuing, it is recommended to move the dialog to one corner of the screen (possibly even minimising the section listing using the minimise button ) and ensure that the target section/plan map window is visible in its entirety. Press the Apply button. Your downhole display settings will now be applied to the selected section/plan. The time taken by Discover to render your settings will be controlled largely by the following:

Note If any display types or modifications fail to render, try enabling the Redraw all data option at the bottom of the dialog. This will force every display type to be redrawn entirely.

Note It is strongly recommended that when first creating a setting template for a drillhole project, work only with one section ( to minimise the rendering time: see the first bullet of step 12 above), and choose one of the more complex sections (typically in the heart of the orebody / mineralisation). This section will likely have the highest density of drilling, scissor holes, splay/daughter holes, etc. If your downhole display scaling/offsets/text sizes can be configured satisfactorily for this section, the resulting template is likely to be viable for most other sections in the same project. Of course, a complex section will be slower to render than an emptier section, so a compromise may be necessary here.


14. The downhole settings applied to your section/plan are now saved with that section: next time you open the section/plan (using the Section Manager), the last display settings applied to it will be displayed.

Missing Downhole Data Tables

Downhole display settings can only be applied to downhole data that was associated with the cross-section/ plan during the process of Creating Planar Sections and Plans. If the downhole data table/s were not selected during this step, Discover will not have included these tables in the section data. Some indications of this issue:

• An error such as " Error plotting data for section - Table not found in the section. Regenerate the section to include missing data" is displayed

• The selected downhole display settings do not appear in the output section/plan window when applied

The three primary situations where downhole data tables may not be associated with your cross-section/plans (and how to resolve them) are:

• For drillhole plans, the "Plot survey traces only" option is by default disabled in the Define New Section or Plan tool (see Plan Definition Parametersl) to help speed up plan generation time for typically larger datasets (often all holes in the drillhole project). If you wish to display downhole data on your plan, regenerate the plan (i.e. rerun the Define New Section or Plan tool) with this option disabled.

• If new downhole tables have been added to a drillhole project after its creation (e.g. downhole geophysics conducted a month after drilling, or assays composited to 5m intervals), open the Drillholes>Project Setup menu option, select the Modify button for the target project, and ensure that under the Downhole tab the new downhole table/s are on the Selected side of the dialog.

• If new downhole tables have been added to a drillhole project after cross-sections or plans were created, first check options 1 and 2 above. The sections/plans will also need to be regenerated to desurvey the new data tables. Rerun the Define New Section or Plan tool, but first check that the new data table/s are selected under the Downhole Data button of this dialog.


Text Labels

Entering parameters for text labelling of drillhole data.

The Text display option displays data in numeric or character attribute fields as labels for each sample or interval down the drillhole. The Text Labels Settings dialog contains options to modify the data range displayed, text styling, positioning, orientation and formatting of the labels on the drillhole section or plan.


Source Data

As with all downhole data setting dialogs, the Table and Field pull-downs need to be first populated with desired targets.

Style

When configuring the appearance of text labels on sections or plans, the primary parameter is the Size (pts). As with many Discover tools, text labels are created as map objects at a specified scale to facilitate professional-looking hardcopy/printed output. By default the drillhole text labels utilise the Global Map Scale set in the main Downhole Data Display dialog.

Generally the label size will need to be smaller when downhole intervals are smaller to prevent overprinting over adjacent intervals. For instance, text labels for 3m assay intervals may display without issues with a font size of 5pts for a map scale of 1:1000, but 1m assay intervals will likely require a font size of 3pts or smaller at the same scale to prevent overprinting issues.

Alternatively, enable the Autoscale labels to fit intervals option to create text labels scaled to the smallest downhole interval.

The Font Style button provides additional text formatting options such as colour, font type, background and effects.

The Cap to minimum... and maximum values will be auto-populated with the selected data field's minimum and maximum values (these will be greyed out if a character field has been selected). If this data range is modified, intervals with values outside the new range will not have a text label displayed. (e.g. an initial data range of 5 -> 5000, modified to 100 -> 5000 will only display labels for this new range). These values can be reset using the adjacent reset buttons, which provide options for using either the data range of the entire table (i.e. the whole drillhole project) or just the selected section/s.

Note Do not override the Map Scale between different display settings.

A powerful way of visualising text labels is by colour modulation using a legend available from the Colour by Legend list. For instance, this can help highlight anomalous regions in assay values not immediately apparent in uniformly coloured text labels. Numeric and character (i.e. attribute) legends can be created and edited using the adjacent Legend Edito rbutton.


Position and Orientation

The position of your text labels is controlled by the Offset parameter in millimetres:

• a negative offset value places text labels to the left of the hole trace


The Set Offset button has a number of preset options to get you started (Near Left, Far Right, etc).

• Perpendicular (default): labels are upright on a vertical drillhole (top of the label is always 'up-hole').

• Horizontal: text labels are uniformly horizontal with respect to the map window (i.e. independent of hole trace orientation)

• Parallel: text labels are aligned parallel to hole trace

• Custom angle: labels are aligned at a user specified angle with respect to the map window (i.e. independent of hole trace orientation), with positive values rotating the labels anti-clockwise. Thus 0 degrees is identical to the Horizontal option above, and 45 degrees angles labels towards the top right of the map window.

Format

Assay laboratories will often return null values such as “sample not received / (SNR)”, or “<0.01 / (BDL)”. In order to keep the assay values in a numeric format (rather than a character field), many databases will therefore store these null values as a negative value (in the numeric assay field) to clearly indicate their status (e.g. -9999 or -0.01).

The user may not however want to see these negative values displayed as text labels in their cross-sections, but instead replace them with a more meaningful text string. Discover allows the user to build a list of their database's null values, and their related text strings in the d_abbrev table, accessed via the browse button to the right of the option. This table is located in theDiscover\Config folder (default installation path of C:\Program Files\MapInfo\Professional\Discover\Config).

The Vertical Position of the text labels within their intervals can be controlled by selecting from Top, Centre or Bottom icons.

The Orientation of text labels can also be modified in a number of ways:


Enabling the Replace numbers with alias from d_abbrev option in the Text Labels Settings dialog will then replace any occurrence of a value in the Number_Code field with the Alpha_Code field value in the d_abbrev table. For example -5 may be replaced by BDL. The entry in the description field is for user comments only (it is not used by Discover).

D_abbrev browser for replacement codes.

Discover will (by default) present numeric data to the number of significant figures in each data value. The user can however specify the number of Decimal Places displayed by enabling this option. This can be set to between 0 and 5 decimal places. For example, 0.08 displays as 0 when formatted to 0 decimal places, and as 0.1 with 1 decimal place.

Histogram/Linegraph

Linegraphs find each interval's mid-point location, and assign this location the interval's data value. The size of the linegraph at this position is then a function of both the data value and a user-defined scale (below). A linegraph / profile is then created by joining these mid-point size locations. Linegraphs are therefore very effective for high density downhole datasets such as decimetre- or even centimetre-scale geophysical measurements. They work best with regular/homogenous downhole interval sizes; if there is a large variation in downhole interval sizes (e.g. 1m vs. 10m), linegraphs can misrepresent the data as the actual interval thickness is not represented graphically.

Linegraphs and Histograms are very effective and powerful ways of displaying numeric data graphically, particularly for identifying and assessing trends along and between drillholes and sections.


In contrast, histograms present each downhole interval as a separate bar with the same size as used in the linegraph, but with the bar 'thickness' correlating with the interval length. As each bar is a polygon, histograms can also be colour and/or pattern modulated using a legend. Thus histograms can be very useful for datasets with variable interval lengths, but can get cluttered for very small interval lengths. Histograms are also slower to render than linegraphs.

Specifying histogram display parameters.

Source Data



Scale

The scale section of the dialog allows the width of your linegraph/histogram to be controlled. This is important for ensuring that linegraphs/histograms do not overprint other data displays and adjacent drillholes, whilst having sufficient width to discern subtle trends.

The width can be controlled either via specifying the:

• Maximum display width (in millimetres) in your eventual layout window, for the Global Map Scale specified in the main dialog. This is a precise way of controlling multiple downhole displays, in order to synchronise the various offsets correctly (e.g. 3 adjacent linegraphs for Au, As & Mo, each 30mm wide maximum, each offset by 35mm to prevent overlapping).

• A precise Scale in millimetres per data unit (e.g. 1:200 or 1:0.001 mm/ppm), for the Global Map Scale specified in the main dialog. This is generally of most use when wanting to simultaneously compare the absolute values of multiple data fields (for instance, setting Cu, Pb & Zn linegraphs to all have a scale of 1: 0.001). It also allows the accurate measurement of downhole values from the graphical display on a print-out using a scale ruler. This option can take some experimentation to get right with respect to the actual resulting width of the displays and offset/overlap issues.

Style

Linegraphs can have their line style, width and colour modified using the provided buttons; this is particularly useful for displaying and identifying multiple linegraphs per hole.

The style of histograms can be either a:

The Cap to minimum... and maximum values will be auto-populated with the selected data field's minimum and maximum values. If this data range is modified, intervals with values outside the new range will be capped to the appropriate limiting value; this can be used to visually “cut” high grade assays (e.g. removing nugget values). These values can be reset using the adjacent reset buttons , which provide options for using either the data range of the entire table (i.e. the whole drillhole project) or just the selected section/s.

Discover can also Log(10) Transform the raw data.

• homogenous colour and pattern using the left-hand style button


Note that applying a legend to a field with the log(10) transform option (see Source Data) enabled will utilise the transformed values, not the raw data. Therefore the legend will need to be built using appropriate log(10) values.

A linegraph cannot be coloured using a colour pattern since the linegraph is created as one continuous polyline for each drillhole. Linegraphs display much faster than histograms as there is just one map object per drillhole.

Position

The position of your linegraph or histogram is controlled by the Offset parameter in millimetres:

• a negative offset value places the display to the left of the hole trace


The Set Offset button has a number of preset options to get you started (Near Left, Far Right, etc).

Clever use of offsets and scales can allow multiple linegraphs and histograms to be placed adjacent to each other, or even coincident, as displayed below.

An example of a complex downhole display involving multiple coincident linegraphs for different assay fields (each coloured for identification), a colour modulated histogram (Cu) and colour modulated text labels (Zn). The Scale controls within the various settings

• colour and/or pattern modulated by selecting an existing legend from the available list. Legends can be created and edited using the adjacent Legend Edito rbutton.


dialogs and the Offset controls in the main dialog make configuring such a display simple.

If displaying a dataset of only valid negative values (i.e. no positive values), an offset can be applied, but opposite to it’s normal parameters. For instance, a 5mm geological Trace Shade is to be applied to the right of the drillhole trace, with a linegraph of a valid negative value (only) dataset offset to the right of this. In the Linegraph setup dialog, set it’s position as ‘Left of trace’, and apply an offset of -7mm (giving a 2mm clearance between the trace shade and the linegraph origin).

Trace Shade

The Facing or direction the linegraph/histogram is orientated towards can be controlled with the left/right buttons.

If the dataset being displayed involves valid negative values (e.g. magnetic susceptibility or EM (electromagnetic) data), the facing option will control the orientation of positive data. Therefore setting a linegraph or histogram to display to the right of the hole trace will display positive values (if any) to the right of the trace, and negative values to the left of the trace. When displaying datasets encompassing both valid negative and positive values, it is recommended to not apply any offset (i.e. set the offset to 0mm), as this position effectively acts as the origin for the display.

The Trace Shade display type is designed for displaying downhole data such as lithology or regolith attributes. This is achieved by displaying a polygon of set width for each downhole interval shaded by a specified colour legend.


Trace Shade settings dialog


The Width of the trace shade polygons are specified in mm relative to the Global Map Scale specified in the main dialog. By default the trace shade polygons are centred on the hole traces; therefore a 2mm wide trace shade will display 1mm either side of the hole trace.

The position of the trace shade can also be specified as an Offset from the drillhole trace. The offset is relative to the centre of the trace shade, so that a trace shade 2mm wide, offset 1mm to the left of the drillhole (i.e. -1mm) is displayed with its right margin flush with the drill trace.

Colour and/or pattern modulate the trace shade by selecting a legend from the list available. Legends can be created and edited using the adjacent Legend Edito r button . If the attribute value for an interval does not match any of the values in the legend, no trace shade polygon is displayed for that interval.


Structure Ticks

Displaying downhole structural data using true dip and azimuth information. Tick marks in this example will be coloured by a legend using the Type field.

First populate the Table and Dip Field pull-downs as appropriate.

The structure measurements may be displayed with either a:

• True Dip for oriented core: this requires a Dip Direction (e.g. azimuth) field to be specified.

The Structure Tick display type enables downhole structural data measurements to be displayed on a drillhole section. Discover generates a line that crosses the drill trace at the appropriate dip angle. The structure measurement may be displayed with either True or Apparent dips.


• Apparent Dip for unoriented core. This will display two structure ticks symmetrical about the drill trace. Zero dip can be set either as measured parallel or perpendicular to the core axis.

Display

If a legend is not used, the default tick display can be modified using the Line Style button.

Output Legend and Reference Scales

• Data Legend: Creates a schematic key of a drillhole trace with text showing the location of each data display attribute, including a legend for each colour pattern used in the downhole display.

Note Apparent dip is only valid for displaying data on cross-sections, not plan views.

Note Note that the dip for oriented core is relative to the core. Discover calculates the correct dip of the structure using the downhole surveys.

Enter an appropriate Tick Length (mm) for the Global Map Scale the drillhole section is to be viewed or plotted.

Structure ticks can be placed at the top, centre or bottom of the measured structural interval.

Structure ticks can be coloured according to entries in another column in the structure table. For example, a type field containing entries such as bedding, foliation, cleavage, etc. This enables different types of structural data measurements to be displayed using different line colours and styles. Specify the Colour by column from the list available, and then select the appropriate legend. Legends can be created and edited using the adjacent Legend Edito r button.

Note It is best to use a text based legend to colour the different structure types such as quartz vein or foliation rather than using a numerical colour legend, even if the structure types have been coded as 1, 2, 3, etc.

The options button at the very bottom left of the Downhole Data Display dialog provides the following functionality:


• Histogram Scale: Creates a data scale for histograms and linegraphs. This scale can also be displayed graphically in the section (or plan) map window. The scale is placed at the top left of the section. To move the scale, ensure the annotation table is editable, select all the scale objects (lines and text) using the marquee select tool and then move them to the desired location.

Example drillhole legend

Using Setting Templates

Downhole display parameters can be saved as a Setting Template, preserving the time and work invested in finessing your potentially complex display parameters. Saved settings templates can be:

• Quickly applied to other new sections.

• Selected during the Define New Section or Plan process, making section plan creation a one-step process.

• Easily reapplied after cross-sections or plans have been regenerated with new drilling (e.g. infill drilling or diamond tails/splays).

• Edited at a later date to include new downhole data, or resolve issues (such as overlaps, text labels too large, etc).

• Duplicated and the duplicate modified to display a different series of display characteristics.


• Applied to other drillhole projects.

• Easily shared between users, allowing uniformity of drillhole section display output within an organisation.

Saving Setting Templates

When all of the display settings have been configured in the Downhole Data Display dialog, and you are satisfied with the resulting section/plan display, press the Save button in the Settings area. Enter an appropriate setting template name, and press OK.

Setting templates are saved by default in a user settings directory. If you are creating multiple setting templates per drillhole project (e.g. the Challenger and Titania prospects each have a number of project-specific settings templates being used, such as geochemistry, regolith, etc), templates can be stored in sub-directories (e.g. named by project) using the New Folder button. These sub-directories are coloured blue, whilst the settings templates are black.

The user settings folder is located at .\Discover\Config\Downhole Data Display Settings (default path specified in Discover Configuration dialog, displayed from Discover>Configuration>Settings). Saved templates are stored as .XML files with a .downhole suffix.

Existing settings templates and sub-directories can also be Renamed and Deleted from within this dialog.

Using Existing Setting Templates

2. From the list of settings available select the required setting and either:

• Double-click on the required setting to populate the main dialog with its parameters and auto-close the Load Settings dialog, or

• Select the required setting and press the Apply button to populate the main dialog but keep the Load Settings dialog open. This is a useful way of quickly previewing the parameters of each existing setting to find the precise one you are after.

In addition to the User Settings saved by the user (see Saving Setting Templates), you can select from two additional setting template types:

1. To use an existing template, whether it is to be applied to new or regenerated sections, or modified, press the Open saved setting button .


• Last Settings Applied: Discover automatically saves the last settings applied with the Downhole Data Display dialog with this template name (overwriting it), regardless of whether they were manually saved to a user-specified name or not. This allows you to easily recover the last session's work

• From Open Section: Discover automatically saves the display settings applied to each section or plan with that section or plan in it's project subfolder as an .XML file with a .downhole suffix. Therefore for any open cross-section you can load its display settings (if applied), and then apply these settings to other sections, save the settings as a setting template, or edit the settings and re-apply to the source section.

3. Once the setting template is loaded (and modified if required), select the section/s to apply it to from the Sections list in the main dialog and press Apply.

4. If an existing setting template is modified/edited, simply resave it (overwrite the existing template) or save it as a new template to preserve the changes.

Note that as soon as a user-named setting template is modified, or a template is loaded from an open section, the Current Settings name is listed as Custom Settings.

Sharing Settings Templates Between Users

As discussed in the Saving Setting Templates section above, setting templates are stored in your .\Discover\Config\Downhole Data Display Settings (default path specified in Discover Configuration dialog, displayed from Discover>Configuration>Settings) as .XML files with a .downhole suffix.

Simply copy and paste the templates to be shared between the different user's Downhole Data Display Settings subdirectories (e.g. via a shared network or portable storage device).

Importing/Exporting Drillhole Projects and Their Setting Templates

When drillhole projects are exported and imported (see importing and exporting Discover Drillhole Projects), only the section-specific setting templates are exported and imported (i.e. those auto-created in each section's sub-folder, as detailed Using Existing Setting Templates). Any settings templates in the user settings directory applied to the project are NOT exported and imported.


To add user-saved setting's templates to the destination computers, either:

• Share the setting templates as discussed in Sharing Settings Templates Between Users (recommended).

• Or, on the destination computer:

• Import and open the project.

• Open it's cross sections. Load the setting template from a representative section using the From Open Section option (see Using Existing Setting Templates).

• Save these settings as a user-named setting template.

• Repeat this for as many representative sections as required.

Displaying Downhole Logs

Discover>Drillholes>Log Display

The drillhole log style display is a valuable means of displaying detailed relationships between multiple downhole variables such as a geochemistry assays, lithology and geophysical readings within a drillhole.

To create a Log Display select one or more drillholes from the collar map window. If multiple drillholes are selected a separate drillhole log is created for each drillhole. The drillhole log is saved to a mappable table in a Non_Earth (cm) projection and named according to the selected drillhole. The drillhole log table can be further annotated and added to the layout window for printing.

The Drillhole Log Display function in Discover can display up to 24 columns of downhole data for one drillhole in a plain log style display.


Drillhole data displayed in log style.

Define Log Display

The log display is defined by choosing a downhole data table, selecting the columns from the table to display and selecting how each of these columns is to be displayed. The log can display up to 24 columns, with column 1 being at the left of the log, and column 24 at the right.


Defining the tables, columns and Display Type in the Drillhole Log Display dialog.

Select a downhole table containing attribute data columns from the Select columns from Data Table pull-down list. The log display may be made up of attribute data from more than one data table. For each downhole table select the attribute columns and the assigned column positions from the Columns to Display in Log dialog.

Select columns to display in Log Plot.


To change the column position for an attribute column click on the Reorder Columns button. Use the Up and Down buttons to move the attribute columns to their correct positions. Remove an attribute column using the Delete button.

Log Display Parameters

Choose a Display Type for each data attribute column. Click the Settings button in either the Columns to Display in Log or Drillhole Log Display dialog. The following Log Types are available:

• Text – Numeric and non-numeric data. By default the Text Style scale box is checked to autoscale text within drillhole log intervals. To modify text size and colour click on the Text Style button. Display text using a Legend or check the Replace numbers with alias from table d_abbrev box if required.

• Trace Shade - Numeric and non-numeric data. Trace shades must be displayed using an associated Legend.

• Histogram – Numeric data only. Histograms may be displayed using a Legend or select a Pen style and Brush style to apply to all histogram bars.

• Linegraph – Numeric data only. Linegraphs may be filled with plain colour using the Brush style colour or from a Trace Shade Legend displayed in another drillhole log column.

The width of each log is set to a 2 cm default but can be modified for each log column. Numeric data can be displayed as log values or between selected minimum and maximum data values. Logs can be scaled by a defined Horizontal Scale. Numeric data options are also available to show or ignore negative values, set negative values to 0 or multiply negative values by -0.5.

When displaying linegraphs or histograms of valid negative value datasets (e.g. magnetic susceptibility or EM data), enable the Show negative values data handling option, as well as the Scale log from minimum value option. This will ensure that the X axis starts at the minimum (negative) dataset value, rather than the default 0 value.

When the log display settings have been setup for each data attribute they can be saved and re-used for other drillhole log displays. Click the Save button and enter a name for the setting. To use a saved setting select the setting from the Saved Settings pull-down list. Use the Remove button to delete a saved setting from the list. By default the Last Settings Used are automatically displayed whenever the Drillhole Log Display dialog is opened during a current work session.


Columns and settings for Log Display.


Global Settings

Defining Global Settings.

A number of log display parameters can be set up as global settings and defaults. Many of these settings, such as the column width and graphic styles, can be overridden in the individual log settings either when the data attribute column is first selected or from the Drillhole Log Display dialog. The following Global Settings and Default Style may be set:

• Log Dimensions - column width, vertical scale, horizontal scale, column spacing, minimum and maximum log depths

• Annotation settings – linegraph scale, column labels, depth ticks, depth lines, axis style and label styles

• Data Handling – negative data value options, replace numbers using alias from the d_abbrev table

• Default Log Styles - numeric and character default log styles, linegraph fill, text style, linegraph pen style, fill style, Log(10) transform, log scale from minimum value


Default Style in the Drillhole Log Display dialog.

Legend Edito r

Drillholes>Legend Editor

Downhole numeric and textual data can be displayed using pre-defined legends. For example, assay values displayed as text labels or histograms coloured by specific data ranges can allow the easy identification of high or low values and trends. Lithological data displayed in a trace shade can have standard colours and/or patterns assigned for each lithological unit. Legends can also be applied to textual data displayed as text labels or structure ticks.

Drillhole legends are created and modified through the Discover Legend Editor, accessed via the Drillholes>Legend Editor menu option.

Available legends are listed in the Legends window on the left hand side of the Legend Editor dialog. When a legend is highlighted in this window the Legend name, Description, Filename and Data Type are populated with the associated legend entries displayed in the main legend window.


Legend Editor dialog showing assigned properties, colours and patterns.

Three operational buttons are located at the base of the Legends List:

• New - Create new legend

• Import – Import a selected setting from a Discover xs_colr.tab to available legends

• Delete – Permanently delete an existing legend file

To save a new or modified legend click on the Save button on the right-hand side of the Legend Editor dialog.

To save legends with another name use the Save As button.

Use the Close button to exit the Legend Editor dialog.


Create New Legend

Create new legend from downhole table.

1. Click New button to display the New legend dialog.

2. To use an existing field in a drillhole downhole table as the basis for the new legend check the Populate legend from dataset or feature database box. Select the downhole table from the Dataset pull-down list and the data attribute column from the Field pull-down list.

If an existing field is not used to create the legend, the number of rows and data range will need to be selected manually.

To create a legend with an even colour spread, select the option Use histogram equalization.


3. Select the legend Data Type from the following options:

• Text – Individual textual categories

• Numeric – Numeric ranges whereby the upper limit of one range is continuous with the lower limit of the next range. Only values that are less than the maximum value for each range are displayed using the range colour. If using the Populate legend from dataset option the maximum value will need to be increased in order for the maximum value in the dataset to be coloured.

4. Select the Number of rows to display in the legend. If a text field is selected as a Data source the Number of rows is automatically populated with the number of unique data entries. (It is recommended to not alter the number of rows in this case).

5. Enter the Data range to use for numeric legends. The data range determines the minimum and maximum data values to display in the legend. The data range is divided by the number of rows to create the initial legend from and to values. If a numeric field is selected from a downhole table as a Data source the Data Range is automatically populated although this value can be changed manually.

6. Enter a Legend name for the output table. If a field is selected from a downhole table as a Data Source the Legend name is automatically created by concatenating the downhole table and attribute field name together. This name can be overwritten with a user-defined name.

7. Click OK to display the legend in the Legend Editor dialog.

Modifying Legend Entries

Each legend is composed of a number of properties that can be modified at any time. To modify a legend select the legend from the list. The existing legend properties will be automatically displayed in the Legend Editor window. For each legend entry the following legend properties are available:

• Row – Incremental legend row number

Note The option for creating a legend from a feature database is only available from within the Discover 3D application.

To condition or filter data from the automatic assignment select the Field Data Conditioning option.


• String – Text legend entry field. Double-click with the mouse in the string column to modify entry (Only available for Text Data type).

• From (>=) – Numeric legend minimum range value. Double-click with the mouse in the From (>=) column to modify the entry (Only available for Numeric continuous Data type).

• To (<) - Numeric legend maximum range value. Double-click with the mouse in the To (<) column to modify the entry (Only available for Numeric continuous Data type).

• Fg (Foreground colour) – Colour used for solid or pattern fills. Left-mouse click in the Fg colour box in the legend entry to display the colour palette.

Select from any of the standard colours available or press Custom to create a new colour. In the Colour dialog select a colour from the Basic Colours palette. Click in the colour spectrum window or enter RGB or HSL values until the desired colour is created. Use the Add to Custom Colours button to add the colour to the Custom Colours palette. The Fg colour can also be set to Transparent to display data with this legend entry see-through.

Colour palette.

• Bg (Background colour) – Colour displayed as solid background fill if a pattern is selected. Selection of background colours is identical to selection of foreground colours (see above)

• Pattern – Pattern displayed for a legend entry. Left-mouse click in the Pattern box in the legend entry to display the available patterns. The pattern selected is displayed with the colour of the nominated Fg Pattern styles are stored in bitmap files located in the .\Program Files\Encom\Common\Patterns directory.


MapInfo patterns.

• LCol (Line colour) – Line colour used for trace shade or histogram boundaries and structure ticks. Left-mouse click in the LCol box in the legend entry to display the colour palette. To copy the Foreground colours to use as the line colours highlight the Fg column entries and press Ctrl-C. Highlight the corresponding lines and press Ctrl-V.

• LStyle (Line style) – Line style used for trace shade or histogram boundaries and structure ticks. Left-mouse click in the LStyle box in the legend entry to display the available styles.

Line styles.

• LThick (Line thickness) – Line thickness used for trace shade or histogram boundaries and structure ticks.

• Comment – Descriptive text entry for each legend row can be stored with the legend.


Additional Legend Modification Tools

• RGB Interp - Interpolate RGB (Red:Green:Blue) shades in colour columns across rows of selected cells.

RGB interpolations can be used with any of the legend colour columns Fg, Bg or LCol. To select the rows to shade either left-mouse click in the first colour cell and drag the mouse cursor to the last colour cell or left-mouse click in the first colour cell and hold down the Shift or Ctrl keys to select the last colour cell. Click the RGB Interp button. The intermediate rows show continuous shading between the first and last selected colour cells.

• HSL Interp - Interpolate HSL (Hue:Saturation:Lightness) shades in colour columns across rows of selected cells.

HSL interpolations can be used with any of the legend colour columns Fg, Bg or LCol. To select the rows to shade either left-mouse click in the first colour cell and drag the mouse cursor to the last colour cell or left-mouse click in the first colour cell and hold down the Shift or Ctrl keys to select the last colour cell. Click the HSL Interp button. The intermediate rows show continuous shading between the first and last selected colour cells.

• Step Patterns - Automatically assign patterns across rows of selected cells. To select the rows to pattern either left-mouse click in the first pattern cell and drag the mouse cursor to the last pattern cell or left-mouse click in the first pattern cell and hold down the Shift or Ctrl keys to select the last pattern cell. Click the Step Patterns button. Each row is displayed in a different pattern according to the order in the available pattern

• Duplicate - Copy a colour, pattern or line style across rows of selected cells. Select the cell to copy and drag the mouse cursor to the last cell or hold down the Shift or Ctrl keys to select the last cell. Click the Duplicate button and all selected cells will be updated with the same parameter as the selected cell.

• Insert row - Insert an empty row above the selected row.

• Add row – Add an empty row to the end of the legend.

Note The Auto-populate “From” fields option selected will automatically populate the From (>=) field with the To (<) value for modified or newly entered data values


• Delete rows - Remove single or multiple rows. Select a row to delete by clicking in the legend row column. Use the Shift and Ctrl keys to select multiple rows. Any cell selection that is highlighted is removed with this operation. A confirmation message is displayed before the rows are deleted.

Importing Legends

Drillholes>Import or Export>Import Discover ColourMap Table

The Discover Import Discover ColourMap Table tool is designed to import legends that have been created and saved on other machines running Discover. Users can copy standard legends between computers in the same office or at different sites.

The drillhole legend parameters are stored in the xs_colr table located in the ...\Discover\Config directory. The xs_colr table stores information relating to the legend name, individual categories or ranges and the background, foreground, patterns and styles used in each legend entry. To import legends using this utility, the table structure must adhere to this format.

Note The columns in the Legend Editor can be automatically sorted by clicking the column header. The sort can be toggled between ascending and descending (successive clicks).

Warning If rows are deleted from a legend they cannot be restored once the modified legend is saved.

Note Individual settings from xs_colr.tab can be imported using the Import function in the Legend Edito r.


XS_COLR table displaying legends.

To import a legend table select the Drillholes>Import or Export>Import Discover ColourMap Table menu option and browse to the directory containing the new legend file. The new patterns are appended to the current Discover xs_colr table and should be available for selection in the Displaying Downhole Data and Displaying Downhole Logs utilities.

For each newly imported legend a .LEG file is created in the .\Program Files\Encom\Common\LUT (Windows 2000/XP) directory (or .\ProgramData\Encom\Common\LUT on Windows Vista). This enables the new legends to be modified using the Legend Edito r.

Export Legends

To send selected drillhole legends to another user, simply copy the corresponding .LEG files from the Legends folder (by default .\Program Files\Encom\Common\LUT on Windows 2000/XP or .\ProgramData\Encom\Common\LUT on Windows Vista).

Place these file in the LUT folder on the destination computer; when the Legend Editor starts, they will be automatically loaded.

Legend Configuration

Use the Settings button to view the current file path for the legend and pattern directories. Legends are stored as .LEG files in the \\Program Files\Encom\Common\LUT directory. The Settings dialog also displays the MapInfow.pen path.


Adding Sections to a Layout

Discover>Drillholes>Add Section to Layout

Select drillhole section, map scale and page size.

The Add Section to Layout dialog enables a user to specify a map scale and page size frame for a drillhole section in the same way as Creating Scaled Maps.

Note When a new user logs on to MapInfo, an individual MapInfow.pen file is created as part of the user install and stored in Windows XP under C:\Documents and Settings\[username]\Application Data\MapInfo\MapInfo\Professional\[nnn]\MapInfow.pen. In order for the Legend Editor to be used correctly this path must be set when a user opens the Legend Editor for the first time. In the above example, the nnn placeholder is the installed MapInfo version installed, where 900 = MapInfo 9.0, 950 = MapInfo 9.5 etc. If the MapInfow.pen path is not visible in XP Windows Explorer select Tools>Folder Options and under the View tab click on the Show hidden files and folders option.

Add one or more sections to the layout window. Select the scale and layout page size for a section and add a section grid, titleblock and scalebar. Create a section collar plan and add to the layout in a separate frame.


1. Select the section to add to a layout from the Select Section window. Only one section can be selected from this window and the layout frame parameters will be based on this section and applied to any additional sections selected in the next dialog.

2. Choose a scale from the Map Scale pull-down list. If the desired scale is not available then choose Custom Scale at the bottom of the list and manually enter a map scale.

3. Select a page size and orientation from the Frame Setup list. To add a new page size see Frame Setup for more information on creating and saving page frames. The page dimensions and map window area covered by the chosen frame are displayed at the base of the dialog.

4. Click the Preview button to check the Map Size frame in the selected section's map window. Adjust the paper and scale size if necessary, and click OK once satisfied. A new menu named Section Output is added the the MapInfo menu bar.

5. Whatever is displayed within this frame in the section map window is what will appear in the layout. If the frame does not appear in the correct location then select the frame in the map window and drag to cover the desired window contents. Do not resize the MapSize frame as this will affect the map scale in the layout. When the MapSize frame is correctly positioned choose Accept Map Position from the Section Output menu.

Section Output menu options.

6. If the MapSize frame is too big or too small for the section map window contents then choose Section Output>Re-Specify Parameters and select a different Map Scale or Frame Setup. Continue this process until an acceptable MapSize frame is created and choose Accept Map Position from the Section Output menu.


Section Layout Option s

Adding scaled sections to the layout window, ready to print.

Once the section map position is accepted the scale, frame width, height, top RL and frame left details are displayed under Frame Parameters in the Add Section to Layout dialog. Click the Preview button to re-size the section map window to frame parameters. The frame parameters can be modified manually if required.

7. To create multiple layouts based on the same frame parameters, highlight additional sections from the Choose Sections to Add window. To view how an additional section will be displayed in the layout, select the section from the list and click the Preview button. If necessary modify the frame parameters to accommodate the additional section dimensions.

8. The Add Plan of Collars to Layout box is automatically checked to include a plan of the drillholes displayed in the cross-section in the layout. The collar plan is opened into a new map window and displayed in a separate frame in the layout above the cross-section. The collar plan can be edited and additional layers such as surface geology added to enhance the layout.


A layout frame can be added to an existing layout if one is already open and multiple sections can be placed in one layout (with multiple pages) or a separate layout can be created for each section. Check the Show section info text in layout box to include information such as scale, section origin X, Y and RL and section orientation on the layout.

9. A section grid is created automatically as part of the section layout. See Adding a Map Grid to Sections for more information. A titleblock and scalebar can be added to the layout window for each section in a similar method to using the Discover map making tools such as Scaled Output. See Creating Scaled Maps and Reference Manual: Customising Title Blocks for more information on titleblocks and creating a customized titleblock.

Note Drillhole collars projected using a custom affine coordinate system (see Affine Transformation) cannot be displayed using the Add Plan of Collars to Layout option.

Note Collar plans are added to the top of the map frame in the layout which may result in a layout bigger than the original page size selected. Select larger page size or create custom map frame as a workaround.

Note This menu option is specifically for cross-sections. If there are multiple plans to print use the Discover>Map Making>Add Scaled Frame to Layout menu option. With either of these functions, frames can be added to existing layout windows, enabling a user to add accurately scaled frames for sections and plans together in the one layout.


Adding a Map Grid to Sections

Discover>Drillholes>Draw Section Grid

Drillhole Section Grid dialog.

The section grid tool will draw a map grid of the front most drillhole section map window. The grid drawn will reflect the real easting and northing coordinates along the X axis, and also the correct vertical exaggeration. If you wish to draw a map grid using the non-earth in-line distance coordinates, use Dsicover>Map Grid.

Select an appropriate X and Elevation Grid Spacing. The section grid may be displayed as Lines, Points or Edge Ticks. Use the style buttons to modify grid linestyles, point symbols, colour and font. Make sure the Label Size is appropriate for the Scale at which the section is to be viewed or plotted.

Section grid labels may be displayed in a polygon mask outside of the map frame and at the top, bottom, left and right in the map window. Use the Other Label Options to modify the text displayed in the grid label or to label only selected grid intervals. The grid file is automatically written to section directory and named using the section name with a “G” extension. To save the grids to a different location or under a different name use the Save As button.


Click on the preview button to preview the map grid and make changes as necessary. Click OK to produce the final map grid.

See Add a Map Grid for more information on Discover grids.

Creating a Section Collar Plan

Discover>Drillholes>Create Section Collar Plan

Use the Drillholes Create Section Collar Plan menu option to create a section collar plan without having to run the Add Section to Layout utility. The collarmap plan can be added to a layout using the Frame Tool from the MapInfo Drawing Toolbar.

Section collar plan.


Interrogating Drillholes

Drillhole information from the graphically selected hole.

Digitizing Boundaries

Drillholes>Boundary Digitizing

Once drillhole sections are created, geological or ore boundaries can be interpreted visually. Section boundaries allow the following functionality:

• The saving and preserving of geological, structural & mineralisation interpretations and trends with the section. These are automatically reopened when the associated section is opened using the Section Manager

• Boundaries can be automatically exported into 3D space for use in Discover 3D( or other 3D applications) for solid generation

• Section boundaries can also be used to restrict the area over which sectional resource calcualtions [hyperlink] are interpolated.

Select the Downhole Info tool from the Drillhole toolbar and click on a drillhole collar. The Downhole Info dialog displays all the data in the collar table along with downhole survey data. To view information from any downhole tables select the table from the downhole data pull-down list.


Boundaries are digitized on the screen in the section map window as polygon map objects into a new section map layer. Each section has a separate boundary table that is stored with the other section tables. Select the Digitize Boundary menu option and choose the section to digitize into from the Available Sections pull-down list. A new editable boundary layer is added to the section map window. This layer is named using the section name and a “B” extension. Select the Polygon tool from the MapInfo Drawing Toolbar and proceed to digitize the boundary into the section boundary layer. When complete, save the section boundary table using the File>Save Table menu option.

To export boundaries, see Export Digitized Boundaries to 3D DXF.

Calculating Sectional Resources

Drillholes>Sectional Resource Calculator

Discover provides a simple method for interpolating resources from cross-sections or level plans. The Sectional Resource Calculator uses a two dimensional inverse distance weighted interpolator (similar to that used in the Discover Surfaces module) to produce a grid of interpolated values. Section grids can be generated over an entire section or contained using a boundary that has already been digitized using the Drillholes Boundary Digitizing utility.

The resource grid is stored as a table named with the section (or plan) name plus a suffix to show it is a resource grid, and stored in the project or section folder.

The Sectional Resource Calculator requires a drillhole project and either a cross-section or plan of the drillhole results to be used for the calculations. In order to ensure that all drillhole assay results which intersect the cross-section are included in the interpolation check the Search all holes box in the Drillholes Define New Section or Plan dialog. This option will ensure that any drillholes that is collared outside of the section envelope but intersects the section envelope at depth are included in the cross-section.

Once the resource grid has been generated it may be contoured, queried or re-coloured using the functions in the Discover SUrfaces module (see Working with Surfaces).

Note Ore resource values generated by the Discover Sectional Resource Calculator are approximation only and should be used in conjunction with other resource calculation applications.


Drillhole plotting dialog and selected Search all holes option.

The sectional resource will generally be contained within a boundary that has been interpreted based on geological or geochemical restraints. Drillhole assay results that lie within the selected boundary are used in the resource interpolation. See Digitizing Boundaries menu option for more information on creating boundaries.


Setup Resource Parameters

1. Select the Drillholes>Sectional Resource Calculator menu option.

Drillhole Sectional Resources Step 1 of 3 dialog.

2. Select the section to be used in the sectional resource calculation and click OK.

Drillhole Sectional Resources – Step 2 of 3 dialog.

3. Use the From Table pull-down list to select the assay table to use in the resource calculation. Highlight the appropriate assay column in the From Column list.


4. If there is a section boundary in the section map window the options to Use Data Bounds or Use Digitized Boundaries are available. The Use Digitized Boundaries option will restrict the sectional resource calculation to within the interpreted ore boundaries by excluding all assay results that lie outside the computed boundary.

5. Check the Convert area to tonnes box to more accurately calculate the resource tonnage. The Width value is the total distance from the section line in either direction to include in the resource calculation. For example, a resource calculation width of 20m is comprised of a +/-10m envelope either side of the section line. Effectively this value is twice the envelope width specified in the Drillholes Define New Section or Plan dialog.

Enter a Specific Gravity (sg) or density for the ore. The section volume is multiplied by this value to calculate the resource tonnage.

If the Use Digitized Boundaries option is selected the Store Resource in column becomes active. Check this box to store the results of sectional resource calculation in a new column named Resource in the digitized boundary table (cross-section table with “B” extension).

Section Grid Parameters

Drillhole Sectional Resources – Step 3 of 3 dialog.


6. The Grid Cell width/height is automatically populated but can be changed to a more appropriate size if required. The minimum and maximum X and Y extents for the output grid are also displayed and may be changed manually if no ore boundary is selected. Enter a Null cell value for any blank grid cells created (default -999999).

The interpolation used by Discover in the Sectional Resource Calculation is a simple two dimensional Inverse Distance Weighted (IDW) algorithm similar to that used in the Discover Surfaces menu. A search ellipse of fixed size and orientation can be defined and a grid cell value is then calculated from the weighted average of all data points that lie within the ellipse centred on each grid cell. If the input data points are not evenly distributed then using an oriented search ellipse may produce a more representative grid.

7. Uncheck the Ignore zero data values or Ignore negative data values boxes to include zero or negative data values in the section resource calculation.

8. The Weight power determines the rate at which the influence of each data point declines with increasing distance from the grid cell being interpolated. Increasing the weighting power reduces the influence distant points have on the calculated value of each grid node. The weighting value defaults to 2 (i.e. the weight of any data point is inversely proportional to the square of its distance from the grid cell) which is appropriate for most situations. If required, the weighting value can be altered to any positive value.

9. Enter a Min points per cell value. This value represents the minimum points required within the search ellipse before a grid cell value can be interpolated and controls the appearance and smoothness of the output grid.

10. For a simple search with no bias in the search orientation use the default Search Ellipse Orientation of 0 degrees. Set the Ellipse Long Radius and Ellipse Short Radius to the same value to create a circular search ellipse.

Note If the minimum number of points is set greater than 1, some cells may report a null value as they do not contain sufficient data points within the search ellipse.


When the mineralisation orientation such as the dip or plunge of the ore body is known, alter the search ellipse parameters accordingly. The search ellipse orientation may be between –90° and 90°, where 0° is vertical and -90° and 90° orientations are horizontal search orientations in the left and right hemispheres respectively. For example, a section with the mineralisation plunge/dip 50° to the right on section requires a search orientation of –40°. The long axis (major) and the short axis (minor) define the search ellipse used by the grid algorithm.

11. The sectional resource grid is saved by default with the section name plus “Resource” suffix in the drillhole section directory. The grid can be saved with a different name and location if required. Choose a colour look-up table to shade the new sectional resource grid from the Image Shading pull-down list.

12. Click OK to create the sectional resource grid. The grid is automatically added to the section map window and the tonnage and grade displayed in a message window. The tonnage and grade is also written to the Resource column of the boundary table if this option was selected.

Downhole Compositing

Drillholes>Downhole Compositing

The Discover drillhole compositing utility composites downhole data in a number of ways:

• Composite by Cut-off Grade – Composite data using a minimum cut-off grade for a specified downhole length or vertical thickness interval. Include internal dilution parameters.

• Composite by RL or Downhole Depth – Composite data using regular downhole elevation intervals such as mining bench RL or downhole depth from surface.

• Composite by Attribute – Composite data using a unique-value attribute such as lithology or alteration. All contiguous intervals with the same attribute value are grouped together and assays composited for each contiguous group.


Compositing dialog options.

Select Drillholes to Composite

By default all drillholes are selected for compositing. To composite a selection of drillholes choose the drillholes in the collar map window prior to running the compositing utility. Alternatively, click the Unselect All button in the Compositing dialog and highlight individual drillholes using the left mouse button. To select consecutive drillholes hold down the Shift key and for non-consecutive drillholes holes hold down the Ctrl key.

Note In the original downhole table to composite make sure that the From and To columns are set to Float or Decimal (particularly if the drillholes are inclined) as the original From and To column formats are carried over into the output composite table. If these columns are set to integers then the downhole From and To depths reported may be incorrect due to rounding to the nearest whole number.


General Settings

Select the table to composite from the Composite from downhole table pull-down list. Select the primary data column to composite from the Composite using value in column pull-down list. Data to composite must be in a numeric column.

Composite data is stored in a new table. The new composite table is named using the original downhole table name with a default Composite table suffix of “_comp”. The suffix can be changed to any user-specific name. All downhole tables in the drillhole project are displayed in the Downhole tables to composite window.

Enabling the Add interval column to output option adds a new column (default name ‘Interval’) to the output table. This will contain the downhole length of each composited interval. An existing field cannot be specified.

Check the Add output to current project box to automatically add newly created composite tables to the current drillhole project. Composite data can then be viewed on a section using the Display Downhole Data tool (see Displaying Downhole Data).

If the downhole table to composite contains character values in other columns, then some composite columns in the composite table may be meaningless. Check the Clear character columns box to avoid incorrect values being carried over to the composite table.

The Select Columns button controls which additional fields are to be composited. By default only the primary field specified in the Composite using value in column pull-down list is selected (along with the compulsory HoleID, From & To fields). Use the arrow buttons to add extra fields to the Selected list (ensure that the primary field remains in the selected list). If additional fields are to be composited, it is recommended to alter the Composite table suffix to reflect the primary compositing field, e.g. ‘_comp_Cu’.


Composite Data Handling Options

A number of Data Handling Options are available in order to assist Discover to composite drillhole data. Downhole assay data is often received in a format that requires some manual manipulation before the data can be used effectively in downhole analysis.

Data Handling Options dialog.

• Negative Values – Negative values can be set to “0” or to a single user-specified value.

Check the Multiply negative values box by -0.5 to convert each negative value to a new positive assay value which is half the detection limit. Alternatively, multiply all negative values by a single user-specified value.

• Zero Values - Zero values can be set to a single user-specified value.

• Custom Template – To apply different replacement values for element data in a table or for multiple replacements within the same element field a custom template can be created. The template must contain three fields which contain the element name, the original assay value and the new replacement assay value. The template must be open in MapInfo in order to be selected for use in the Data Handling Options dialog.


Composite by Cut-off Grade

Compositing by cut-off grade is commonly used to summarize assay data into intervals above a specified value. A minimum interval length can also be specified along with internal dilution constraints.

The composited interval is calculated using a downhole running weighted average of consecutive samples that conform to the cut-off grade parameters. Cut-off grade composites can only be calculated for one element at a time.

Compositing by cut-off grade.

• Minimum Grade

Enter a minimum grade for a sample to be included as part of the composite. The downhole running grade is also assessed against the Minimum Grade; if it falls below the Minimum Grade, the composite is stopped (unless Internal Dilution has been specified).


• Cut High Values to maximum

Enter a maximum grade for a sample to be included as part of the composite, any grades higher than the specified value will be automatically treated as the high cut value.

• Minimum Length

A minimum length downhole (e.g. 5m) can be set for samples over the cut-off grade. If the minimum length is not reached then the samples are not included in the final composite table.

• Minimum Vertical Thickness

A minimum vertical thickness (e.g. 5m) can be set for samples over the cut-off grade. If the minimum vertical thickness is not reached then the samples are not included in the final composite table.

• Internal Dilution

It is not uncommon for samples above the cut-off grade to be separated by samples with low grade assay values. Due to restrictions such as minimum mining width, it may be necessary to include this material as part of a composite interval.

An internal dilution thickness and grade can be set so that low grade material can be included in a composite under specified conditions. If the low grade material is above the internal dilution grade, it will be included as part of the composite as long as its thickness is less than the specified internal dilution thickness. Low grade material is not added to the end of a composite interval.

Internal dilution can be calculated as either a composite (default) or applied as a minimum dilution grade. For example, if Internal Dilution is set to 5m @ 50ppb, with the Composite option checked, an interval of 5m @ 63ppb would be valid regardless of the actual sample values making up this interval. However, if the Composite option was unchecked, and the 5m @ 63ppb incorporated 1m @ 30ppb, the interval would not be valid.

• Edge Grade

Specifying an Edge Grade allows the application of Edge padding when downhole compositing. The Edge Grade value (GE) should be set between the Internal Dilution (GD) and Minimum Grade (GM) values. Edge Grade can only be used when Internal Dilution is applied. The maximum Edge Grade thickness uses the value set for the Internal Dilution thickness.


Edge Padding allows a composite ending in a valid internal dilution interval to be carried through to a sample >=GM if the intervening interval meets the Edge Grade requirements (and the overall running grade >= GM throughout).

For example, if:

GM = 500ppbInternal Dilution is 5m @ 50ppbGE = 250ppb(and assuming that the running grade is >=500ppb across the composite)

The following interval would be treated as a continuous composite:

The following interval would finish the composite at 120m:

The following interval would also finish the composite at 120m:

Depth Interval grade Interval length

105-120m 702ppb 15m

120-125m 89ppb 5m valid internal dilution

125-127m 400ppb 2m valid edge padding

127-130m 550ppb 3m


105-120m 702ppb 15m


125-127m 230ppb 2m invalid edge padding

127-130m 550ppb 3m


105-120m 702ppb 15m



Composite by RL or Downhole Depth

Compositing by RL or depth is useful to normalize downhole data tables to a consistent sampling interval or mining bench height. For example, a hole collared at RL 257.9m and composited at 10m RL intervals might have downhole intervals of 0-10.09m (257.9-247.9m RL), 10.09-20.206m (247.9-237.9m RL), etc. The same hole composited at 10m Downhole Depth intervals has intervals of 0-10, 10-20, etc from surface. In the case of vertical holes these composite intervals and grades will be identical. For inclined holes, choosing the RL composite option will mean that the actual down-hole interval will be larger than that specified; the RL interval is measured vertically whilst the downhole interval is at an angle.

In both instances the composite is calculated using a weighted average based on samples that fall entirely and partially within the designated composite interval. If a composite interval contains no samples or missing samples then a zero value is inserted and used in the final calculation.

125-131m 300ppb 6m length>internal dilution width

131-134m 550ppb 3m



Compositing by elevation.

Composite by Downhole Depth

Downhole depth composites are calculated using the From and To intervals in the downhole table.

1. Click on the Elevation tab in the Compositing dialog.

2. Enter a suffix for the composite table to be created or leave the “_comp” as the default in the Composite table suffix window.

3. Choose the downhole table to composite from the Downhole tables to composite list and use the Select Columns option to select the data columns to composite plus any additional columns to display in the results table.


4. Check any other options under the General Settings to display an interval column in the results table, clear any character columns and add the newly created composite table to the current project as required.

5. Select Downhole Depth as the composite type

6. Enter the interval to composite by into the Composite at elevation interval box.

7. If only a portion of the drillhole is to be composited then enter a Start RL (max) and/or End RL (min) depth into the appropriate boxes; e.g. Start at 10m downhole and composite at 10m intervals until End depth of 80m is reached.

8. Click OK to create the composite table.

Composite by RL

Compositing by RL (Reduced Level) is used for situations where absolute elevations are required. For example; to create a composite grade for mining bench extraction purposes. RL composites are calculated by converting the From and To intervals in a drillhole to the corresponding downhole XYZ coordinates and using the Z value for each sample to determine whether it falls entirely within or partially within a composite interval.

1. Enter a suffix for the composite table to be created or leave the “_comp” as the default in the Composite table suffix window.

2. Choose the downhole table to composite from the Downhole tables to composite list and use the Select Columns option to select the data columns to composite plus any additional columns to display in the results table.

3. Check the Add output to current project box (this is needed in order to calculate 3D coordinates for the table later). Check any other options under the General Settings to display an interval column in the results table or, clear any character columns as required.

4. Click on the Elevation tab in the Compositing dialog.

5. Select RL as the composite type

6. Enter the interval to composite by into the Composite at elevation interval box.


7. Enter the Start RL (max) elevation and/or an End RL (min) elevation depth into the appropriate boxes if:, e.g. Start at 200 RL and composite at 10m intervals until End RL of -150 RL is reached. If no end RL is entered then the compositing will continue until end of hole depth is reached.


The initial composite table contains all the selected columns from the original table plus the downhole composite column/s and interval column if this option is checked.

The From and To columns which are displayed in the results table are the downhole intersections which correspond to the RL values. In order to display the corresponding RL or Z value for each composite interval the following steps are required:

9. Go to the Drillhole>Project Setup menu option and select the current drillhole project and click OK. This is required in order to make sure the drillhole project registers the new composite table in the list of available downhole tables.

10. Select Drillholes>Calculate 3D Coordinates and choose the newly created composite table. (You may need to also select the downhole Survey table if one is present and the downhole 3D coordinates for this table have not been calculated already.

11. Click OK to calculate the 3D coordinates and re-display the composite table in a browser window.

The Calculate 3D Coordinates utility adds six new columns to the composite table with the corresponding XYZ for the From value (XF columns) and To value (XT columns). The XFR and XTR columns contain the RL values for the upper and lower composite interval.

Composite by Attribute

Compositing by unique attribute is generally used to merge contiguous drillhole intervals together that contain the same attribute, e.g. Lithology, alteration, etc. A table may be composited using the intervals generated from compositing a column in another table, e.g. assay grades can be composited based on lithology composite intervals. Numeric values are composited with a weighted average.


Compositing by attribute using assay data in one table with lithology data in another table.

To composite assays based on lithology:

1. Click on the Attribute tab in the Compositing dialog.

2. Select the lithology table from the Composite using downhole table pull-down list.

3. Select the column from the lithology table containing the attributes to composite by from the Composite using value in column pull-down list, e.g. Geology_Code

4. Choose the assay table to composite from the Downhole tables to composite list and use the Select Columns option to select the elements to composite plus any other columns to display in the results table.


5. Check any other options under the General Settings to display an interval column in the results table, clear any character columns and add the newly created composite table to the current project as required.


Calculating 3D Coordinates

Drillholes>Calculate 3D Coordinates

3D coordinates for downhole samples do not need to be calculated in order for the data to be displayed in Discover. However, these coordinates may be needed if the data is to be transferred to another data processing or visualisation software package.

Calculate 3D coordinates.

The Calculate 3D Coordinates function updates the selected downhole data tables with easting, northing and elevation values for the top and bottom of each sample. The coordinates are written into columns with specific names XFE, XFN, XFR, XTE, XTN, XTR respectively. If the columns do not already exist in the table new columns will be created.

A summary of the fields created for each interval are listed below:

XFE - Top of the interval (e.g. ‘From’ field) Easting coordinate

XFN - Top of the interval (e.g. ‘From’ field) Northing coordinate

XFR - Top of the interval (e.g. ‘From’ field) Elevation

XTE - Bottom of the Interval (e.g. ‘To’ field) Easting coordinate

XTN - Bottom of the Interval (e.g. ‘To’ field) Northing coordinate


XTR - Bottom of the Interval (e.g. ‘To’ field) Elevation

If the downhole tables are stored in an Access database, Discover cannot set the order of the 3D coordinate columns. In this instance the 3D coordinate columns are created as the first 6 columns in the downhole table. This is likely to invalidate the drillhole project column assignments that Discover stores. After calculating 3D coordinates for the Access downhole table, modify the column order in Table>Maintenance>Table Structure and the column assignments in Drillholes>Project Setup.

Calculating 3D Coordinates Midpoint

The Calculate 3D Coordinates function updates the selected downhole data tables with easting, northing and elevation values for the top and bottom of each sample. These values can be used to calculate midpoint easting, northing and elevations between the calculated 3D coordinates.

1. Using Table>Maintenance>Table Structure, add 3 new float fields (Mid_E, Mid_N, Mid_Z) to your downhole data table.

2. Populate each of these fields (Mid_E, Mid_N, Mid_Z) successively using Table>Update Column function. For example, to update the Easting midpoint select the Column to Update as Mid_E and populate the Value field with (XFE+XTE)/2. This calculation will define the midpoint value for the easting. Repeat for northing and elevation.

Note If a downhole data table that includes 3D coordinates is composited, the 3D coordinates must be re-calculated after the compositing is complete.

Note The midpoint calculation method is primarily designed for straight drill traces. If individual drill traces contain multiple inflections, as indicated in a survey table, the midpoint calculation may not accurately reflect the exact midpoint value.


Calculate Easting Interval Midpoint.

3. Save the table when finished.

4. To position these interval midpoints spatially, independent of a drillhole project:

• First query out the desired data (e.g. using SQL Select select all Au values above 50ppb, or use the Data Utilities>Select by Group tool to query out all intercepts with say a QV code).

• Save this query as a new table (File>Save Copy As).

• Open this new table, and use the Table>Create Points tool on your new Mid_E and Mid_Y columns in the appropriate projection.


Calculating Maximum and EOH Values

Drillholes>Calculate Maximum and EOH Values

The Drillholes Queries tool enables the extraction of both maximum downhole grade and end-of-hole (EOH) data values for selected elements. The Maximum and EOH values are saved to new tables which can be added to a drillhole project for analysis e.g. enrichment zones or mineralized trends, or subsequently analysed.

Analyse Maximum Downhole Grades

Analysis of maximum downhole grades for selected elements, for each individual drill collar, is achieved by selecting the Max Values tab. Maximum downholes grades will only operate on numerical data fields.

Maximum Values dialog.


Define the Downhole Table to analyse the maximum values from the dropdown list available under the Input option. By default a Hole ID and maximum downhole grade will be displayed in a MapInfo Browser format. To display the respective interval where the maximum grade exists select the Display From and To values option.

Numerous options exist for selecting elements to interrogate.

Select additional element columns dialog.

The Output table for the maximum values analysis will automatically be saved into the drillhole project folder; and alternate path can be defined if desired.


Additional element columns can be selected to interrogate the respective data values and the maximum value for the primary maximum element values. The data values for the additional elements will be displayed, note that these are not the maximum values for these elements downhole.

Select

Unselect


Analyse EOH Downhole Grades and Data Values

Analysis of EOH downhole data for selected elements, for each individual drill collar, is achieved by selecting the EOH Data tab. EOH downhole data will operate on both numerical and character data fields.

EOH Data dialog.

Define the Downhole Table to analyse the EOH values from the dropdown list available under the Input option.

By default a Hole ID, From, To, EOH and selected elements columns will be displayed in a MapInfo Browser format.


Numerous options exist for selecting elements to interrogate.

When selecting Use deepest sample/interval the values for the selected column report the interval at which the last downhole data value appears.

When selecting EOH Check the values for the selected columns, by default report an EOH depth as specified in the collar table. A data value may or may not exist at the reported depth. If no data values exist at the EOH depth two text boxes No sample string and No sample value are available to populate user defined null values. The numerical toggle box for the EOH Check option allows a fault tolerance value to be set. For example, if the total depth for a drill hole was 100m and the last sample interval was 99m the EOH values would be a null. If a fault tolerate value of 1 was set the EOH routine would report the EOH value at 99m. The fault tolerance only applies to EOH values which are null or are not populated with an interval value.

The Output table for the maximum values analysis will automatically be saved into the drillhole project folder; and alternate path can be defined if desired.


Two options exist for analysing EOH data; either Use deepest sample/interval or EOH Check.

Note The EOH column will be populated with either a T or F indicating if the EOH displayed is the actual EOH value. A T indicates a true result; therefore the EOH depth is the actual collar EOH. An F indicates a false result; therefore the EOH depth is either shorter or longer than displayed.

Select

Unselect


Saving Display Settings

When displaying drillhole data in Discover, there are a number of ways to save display settings to make it easy to obtain consistent output from one session to the next. These various methods have already been described previously but are listed here to provide a summary.

• Legends – Created using the Legend Editor menu option. Used for numeric (ranged) or character (individual) downhole data display in drillhole section or log view. The legends can also be used with surface sampling data (see Colour Map Objects from Look-up Tables). Settings are stored in the xs_colr.TAB table in the Discover\Config directory.

• Downhole Data Display Setting – Used to store the parameters for displaying downhole data in section or plan. The setting lists which data columns are to be displayed and how they are to be displayed e.g. Text, trace shade, histogram, etc. The display method also includes scaling and colouring information. Each Setting files are stored in the "Downhole Data Display Settings" folder in the Discover\Config directory. Applied settigns are stored in each individual section's folder.

• Log Display Setting – Used to store the parameters for displaying data in log view. The log display settings list the global display parameters, the columns to display and the log display parameters for each column. Settings are stored in the xs_disp.INI table in the Discover\Config directory.

16 Working with Surfaces 565

16 Working with SurfacesThe Discover Surfaces module provides a rich suite of functions and tools for creating, modifying and analysing gridded surfaces. The Surfaces module has been designed to integrate seamlessly with gridded data created externally from MapInfo and with other Discover modules that use gridded data such as Drillholes.

For information about the grid types supported and grid handlers, see Introduction to Surface Gridding. For information on importing and exporting grids, see Importing and Exporting.

The Surfaces module provides the following additional functions:

Create Grids

• Interactive Gridding: Interpolate gridded surfaces from point, polyline or polygon objects using a variety of methods: Inverse Distance Weighting, Kriging, Triangulation, Spatial Neighbour, Minimum Curvature, Density or Distance. Dynamically preview the output grid and adjust the interpolation parameters on-the-fly.

• Large Multi-file Triangulation: Interpolate multiple large data sets with millions of points or polylines to build a massive grid using triangulation.

• Converting Vector Surfaces to GridsCreate a 2D surface grid from a 3D vector file, such as a continuously triangulated surface e.g. DXF or Datamine wireframe files.

Import grids

• An extensive range of industry formats are supported. For more information about importing grids and other data types (for example, points and polylines that you can then grid), see Importing and Exporting.

Change the appearance of grids

• Grid Colour and ShadingAdjust grid display with various colour schemes and stretching options, view data histogram and apply sun-shading to a grid.

• Display a Colour LegendDisplay a colour-value legend for a grid.


• Filtering GridsApply Convolution smoothing, enhancement, sun-angle or geophysical FFT filters to a surface grid.

Create contours, profiles and polygons from grids

• Contouring a GridCreate, format and label contours from a surface grid.

• Creating Polygonal Regions by Selection CriteriaCreate colour-filled polygons bounding regions of a grid that meet selection criteria. Criteria can be set by value ranges or surface properties, such as slope and aspect.

• OutlineOutline grid bounds or non-null regions as polygons.

• Creating Grid ProfilesGenerate sectional profiles across a grid or contour plan including draped vector layers.

• Creating Voronoi Polygons Create Regions from point sample data with option to be bounded by a selected boundary.

Interrogate and analyse grid surfaces

• Interrogating a GridInteractively query grid cell values and report summary statistics for the entire grid or within polygonal bounds.

• Calculating Surface Properties and VolumesCalculate the surface area, roughness, slope, curvature, and aspect of a grid. Calculate the volume between a surface and a horizontal plane, or between two surfaces, or the cut-and-fill volumes.

• Hydrological Surface AnalysisExtract steam networks and catchment regions from a topographic grid surface.

• Classify, ViewshedClassify grid regions by data ranges. Determine line of sight (view shed) regions.


Modify and transform grids

• Manipulating GridsClip grid extents to a region or the bounds of another grid. Reproject into a different projection. Convert between formats. Any manipulation is possible including flip, merge, replace, resample, rotate, shift, split, fill holes, and more.

• Edit, OverlayEdit individual grid values or overlay a region of grid cells with a new value.

• Computing Grid Values by ExpressionsPerform complex grid arithmetic, statistical and Boolean calculations on one or more grids.

• Dividing Grids into TilesLarge grids can be 'tiled' (i.e. subdivided) into a number of smaller grids without needing to open the source grid into MapInfo.

Populate map objects from grids

• Assigning Values from a Grid to Map ObjectsAdd grid cell values as attributes to overlying point, polyline and polygon objects.

Other gridding tools

• Pre-computing Grid StatisticsPrecalculate the grid statistics for grid files located in a directory, creating a summary statistics file (.GHX). This process can be reapplied to 'out-of-date' statistics files or used to increase the statistics sampling density for larger grid files.

• Grid Handler PreferencesSet the default grid loading preferences, including the grid appearance and density of precomputed statistics. Also enable/disable available Grid and Raster handlers.

Introduction to Surface Gridding

A surface grid is a rectangular array of points, each of which has an interpolated Z or height value. The Z value in a grid may represent either real heights (such as topographic elevation, depth to weathering or coal seam thickness) or may represent a geochemical, geophysical or other value (such as gold concentration, radiometric total count or rainfall).

http://data.geocomm.com/dem/






The surface grid is generated from a set of input points each of which have a location and a Z value for that location. The regular surface grid is generated from the irregularly distributed input points by calculating interpolated values at regular positions.

It is important to understand that the interpolated values are approximations only of the real values of the surface and that the interpolated values differ depending upon the interpolation method used. With some interpolation methods, it is possible that the interpolated value is slightly different to that of a data point at the same position.

Regular grid of interpolated points generated from irregularly distributed input points

Once a regular grid of interpolated values has been calculated and stored, it can be displayed in MapInfo. The grid can be displayed as a set of rectangular polygons, each one representing a grid cell.

If the grid cells are stored in a simple format of cell coordinates and value, then Discover can display them in MapInfo as a raster image. This method of display is significantly quicker than for polygon grids and allows large grids to be handled efficiently.

A third way in which a grid can be displayed is as contours. Contours are generated by tracing lines of equal Z value across the grid. The contour lines do not provide as much information as a grid, but do offer another visualisation method. This is useful for displaying contours of one grid over a second grid (for example, soil geochemistry contours over a magnetics grid).

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MapInfo Professional and Grid Files

To import an existing grid into MapInfo Professional, the standard File>Open option can be used by setting the format file type to Grid Image. This will import most common grid formats. Some specific formats such as SRTM HGT and multi-banded grids need to be imported with the Discover Surfaces>Import Grid File menu. See Supported Grid Formats for detailed information.

When importing a grid with File>Open, you may be asked to select a projection for the grid file; this should match the registration points embedded in the grid file, if known. If the registration of the grid is incorrect, you can use Table>Raster>Modify Image Registration to correct the TAB file registration information.

Errors can occur in the projection of a grid image via the MapInfo File>Open menu if the embedded Grid File registration is incorrect. To edit the embedded registration points, use the tools on the Surfaces>Import Grid File menu to import and register BIL, ER Mapper, Geosoft, Surfer, HGT SRTM, Vertical Mapper, USGS SDTS TAR, Minex and ASCII grids using Discover.

Supported Grid Formats

Discover adds support to MapInfo Pro for direct reading of numerous standard grid types. Discover's grid handlers also support opening, modifying, manipulating and editing multi-gigabyte grid files.

Grid formats supported through File>Open are:

• ASEG GXF (.GXF)

• Band Interleaved by Line (.BIL including .HDR)

• Encom Grid (.GRD)

• ER Mapper (.ERS)

• ESRI/Arc Binary (.ADF)

• ESRI/Arc ASCII (.ASC)

• Geopak (.GRD)

Note Many of the grid formats created in Discover cannot be opened in MapInfo without Discover installed.


• Geosoft (.GRD)

• Landmark (.GRD)

• MapInfo Grid (.MIG)

• Minex (.XYZ)

• Surfer ASCII (.GRD)

• Surfer Binary (.GRD)

• USGS (.USG)

• USGS DEM (.DEM)

• USGS SDTS (.TAR)

• Vertical Mapper (.GRD)

In addition, there are dedicated import tools under the Surfaces>Import Grid File menu to import the following:

• ASCII files (.TXT, .CSV, .XYZ) - converts delimited grid coordinates and values into a standard grid file format which can be subsequently opened

• HGT SRTM files (.HGT) - creates an ERS which can be subsequently opened

• Multi-banded grid files can be Split into individual grids for opening using the Surfaces>Grid Utilities>Split tool

• Grids created by Vertical Mapper will need to be converted from a raster to a grid image using Surfaces>Import Grid File>Toggle Support for Vertical Mapper Grid

You can define the default appearance of grids, and enable or disable various handlers used by MapInfo Professional using the Surfaces>Grid Handler Preferences tool.


About Grid Handlers

When surface grids are created internally, the Discover Surfaces module can assist these operations by creating a grid surface in a format of your choice

To set the preferred grid format, use Discover>Configuration>Grid Handlers and select the Default grid output format.

Grid Format Selection for preferred operation

Once a grid format has been selected, all grids created from this point use the specified format unless an interface option exists to override the setting. You can alter the preferred Grid Handler used by Discover by selecting another at any time.

Creating Grids

The Surfaces modfule provides two powerful gridding options:

• Interactive Gridding: Interpolate datasets such as geochemical, geophysical or spot height measurements using methods such as IDW, minimum curvature, kriging or triangulation. Dynamically preview the output grid and adjust the interpolation on-the-fly.

• Large Multi-file Triangulation: Interpolate single or multiple files encompassing millions of points or contours to build a massive grid using triangulation.


Interactive Gridding

Surfaces>Create Grid>Interactive

The Interactive Gridding tool in Discover has an optimised internal data interrogation system that automatically analyses the spacing and distribution of the input data and computes an optimal set of gridding parameters. If the default parameters and gridding method are not acceptable, these settings can be overwritten by entering a user-defined method, grid cell spacing, search criteria etc.

Discover Gridding Tool dialog showing grid image and tab options

Gridding starts by defining a set of input data points to be included in the gridding process. The points to grid can either be from a nominated table or from a selection made using the MapInfo selection tools. Irregular or regular shaped collections of data points can be gridded. Other coordinated objects, such as polylines or polygon contour files, can also be gridded. The nodes within the object are extracted and treated as individual points, containing the same attributes as the object.

Discover provides a high performance, optimised gridding tool to assist with the creation of interpolated surfaces in MapInfo. The Gridding Tool is set out in an easy to use tab dialog to guide you through the entire process. The high level of optimisation in each of the gridding algorithms used in Discover has made it possible to include a real-time preview window to assist in choosing the best parameters for the data. This preview window allows users to experiment with different gridding parameters in real-time and observe the effect they have on the quality and appearance of the grid.


If the gridding process is initiated from the shortcut menu on a map layer in the ELC, then the selection dialog is not displayed and the layer highlighted will automatically be selected for gridding.

Using the Interactive Gridding Tool

The gridding tool is controlled via a series of tab pages to the left of the preview window. The number of visible tabs in the dialog varies depending on the gridding method selected (see Gridding Tool Method Tab), however the four main tabs are always visible irrespective of the gridding method selected:

• Gridding Tool Input Tab

• Gridding Tool Method Tab

• Gridding Tool Geometry Tab

• Gridding Tool Output Tab

The operation of each tab control is described below.

On the bottom left side of the dialog are Save, Cancel and Help buttons. The Save button creates an output surface as specified on the Output tab. The preview window does not have to complete drawing before saving the output grid file. If the initial appearance of the grid is satisfactory click the Save button and the grid is saved in the same folder as the input data points. The saved grid is then loaded automatically into MapInfo and placed in the same window as the input data points. The Cancel button dismisses the grid tool without creating an output surface and the Help button displays the on-line help.

Two additional controls at the base of the dialog determine the operational mode of the Gridding Tool. An Auto Apply mode is enabled by ddefault - in this mode Discover automatically updates the appearance of the grid after each parameter change. With Auto Apply disabled, the Apply button allows the user to manually select when to apply the gridding parameters changes to the preview grid. The two operational modes are described below:

• Automatic mode - This is specified with the Auto Apply checkbox enabled and is the default behaviour. As changes to any control parameter are made, the gridding process automatically re-computes and updates the preview display. The Gridding Tool can detect when a parameter change has been made and will apply this change when the cursor is moved to another tab page or field in the dialog.


• On Demand mode – Disabling the Auto Apply checkbox places the gridding tool in manual mode. No grid processing is commenced until the Apply button is selected or the Auto Apply mode is enabled. This mode is best used for situations where a number of parameters are to be modified prior to gridding, or the dataset is very large and the gridding operation may take some time. If the button is disabled then no changes are pending and no grid computation is performed.

A vertical progress bar is displayed next to the preview window in both modes and will show the percentage progress of the gridding operation. The progress can also be monitored by observing the grid re-draw in the Gridding Tool Preview Display.

Gridding Tool Preview Display

The appearance of the preview display can be controlled by four toggle buttons and a pull-down list located above the preview window.

These control buttons are:

Note The Gridding tool will automatically switch to On Demand mode if a large dataset is loaded. In this mode, select a field to grid and press the Apply button to display the grid before proceeding beyond the Input tab page.

View input points in the preview window. Click button to remove input points from view.

View search ellipse in the preview window. Only available if Inverse Distance Gridding method is selected.

Apply a Histogram Equalisation stretch to the image in the preview window. This button can be used to distribute colours more evenly across the image and is particularly useful for data with poor dynamic range.

Display images in the preview window as either coloured or monochrome (e.g. greyscale from black to white). This button toggles the image between monochrome and colour.

Apply a sun illumination to the image in the preview window. This can be used to enhance detail within a gridded image. The sun angle is fixed from the north-east direction.


A pop-up menu can also be accessed by right-clicking with the mouse in the preview window:

Preview window right-click mouse options

The Zoom and Pan controls enable the grid to be examined prior to saving. To zoom in (by 4 times magnification) on an area position the cursor over the area of interest and click the left mouse button. Click the left mouse button again to zoom out. The zoom factor can be changed by selecting the Settings menu option.

Pan a zoomed image by selecting Pan Mode and holding down the left mouse button. The cursor will change to a hand when in Pan Mode. When the button is released the image redisplays at the panned location. Other options include Show Value at Cursor when the cursor is placed over a grid cell and View Input Points to display the original data point locations. If the interpolation method chosen is Inverse Distance Weighting the View Search Ellipse option is enabled to view the search radius used to calculate the grid cell values.

Interrogate the quality of the interpolated surface using the Statistics Explorer. The individual grid nodes of the interpolated surface can be extracted and then examined in a spatial or frequency mode using the Statistics Explorer. Refer to the section on Statistics Explorer for details on how to use this utility.

Select a look-up table to colour the grid. The chosen colour table will be applied to the gridded image when loaded into Discover.


Gridding Tool Input Tab

The input tab summarises the input data and provides a selectable list of all numeric data columns that are available for gridding in the source Tab file or query. Basic summary information is provided for the selected data including minimum and maximum easting (X) and northing (Y) values for the minimum bounding rectangle that fully encloses the input data and a count of the total number of input points (with X,Y pairs).

Numeric data columns from the Input tab file are listed in the Fields (bands) to grid list. To change the column to be gridded select the column name so it is highlighted. Multiple fields (or bands) may be gridded at the same time. The data range for the selected column(s) is automatically displayed in the text boxes to the right and if the Auto Apply option is enabled the grid is regenerated for the new column. If the Auto Apply option is turned off then click the Apply button to display the grid in the preview window. To view multiple gridded fields select the field from the pull-down list displayed above the preview window.

Breakline data can be read from a MapInfo TAB file. Break lines are defined as multi-segment lines in which the slope is monotonically increasing or decreasing along each segment. Examples of breaklines include stream or river traces, topographic ridge lines or roadways. By incorporating break lines into the gridding process the output grid can be forced to conform to certain slope requirements in critical areas.


The Breakline Advanced Options dialog enables you to browse and select an input TAB file. Only one input file can be selected. To identify the breaklines it is necessary to select a LINE field from the TAB file. All vertices from all features with the same LINE identifier will be considered to be a single break line. This means that a collection of points can be grouped into polylines but it also means that polylines will need to have a unique LINE identifier if they are to be considered unique. A Z field must also be specified. It is assumed that the Z data will be compatible with the data field selected to grid. In order to define breaklines with a variable Z attribute for each node (or vertex) in MapInfo the data must be represented as a collection of points. These points must be assigned a LINE identifier to distinguish them as being part of a particular break line. By defining the break lines in MapInfo as a collection of points identified using a LINE identifier it is possible to represent complex 3D geometries such as streams, slope ridgelines or cliffs.

The Coincident points pull-down list controls the handling of multiple data points at the same location. Coincident points may be averaged, the first or last point value that does not contain a null value used, the minimum or maximum point value taken or all points kept.

Input Tab showing two selected fields to grid

In the case of a selected subset of a table, the east and north data values indicate the selected data coverage and not the data range of the original table.


Statistics Explorer

The Statistics Explorer is a utility for examining and understanding the spatial and statistical aspects of a data set. It has been designed in a way that allows for intelligent interrogation of a data set to help identify spatial and frequency relationships which may be important when choosing and configuring an appropriate gridding method. The operation and functionality of the Statistics Explorer is described in the Statistics Explorer section later in this chapter.

Data Conditioning

The Grid Conditioning dialog


The Data Conditioning options enable data to be modified prior to gridding by applying one or more of the following processes:

• Clip Input Data

Specify maximum and minimum X and Y extents to conduct a data clip. The source dataset is clipped to the X and Y extents by checking the Apply data clip option. These values can be reset to the initial dataset extents by pressing the Reset extents to input button. All source data points outside the defined region are ignored and do not contribute to the gridding.

• Define NULL Values

Null values are used to flag specific values in a dataset that are not to be included in gridding process. These may include values indicating Sample Not Received (SNR) or Below Detection limit (BDL), etc. These samples may be attributed with a negative numerical value such as -9999 or -0.5 (detection limit). Failure to remove such artefacts can result in meaningless output grids.

The Null values are set for one or all bands in data to be gridded in the Field Data Conditioning dialog.

• Cap Input Data Bands

Data capping options can be set to prevent outlier values in the dataset from being included in the gridding process. For example a maximum cap value can be set for gold assays which occur in mineralisation systems prone to nugget effects. Capping data to remove very high or very low values is used to remove samples which may unduly influence the cell values in the output grid.

Setting a Cap minimum or maximum value will cap source data outside the set limit to the limiting value. For example, if the Cap maximum value is set to 500, a gold assay with a value of 725 ppm will be handled during gridding as having a value of 500 ppm value.

• Specifying background values

It is also possible to check the Convert NULL to background box and enter a user specified value in order to constrain the gridding. For example, if gridding drillhole geochemical assays, much of the hole may not have been sampled and in these areas the assay result may be assumed to be equal to the background value. This helps prevent anomalies ‘ballooning’ into areas with no source data coverage.


The options presented in the Grid Conditioning dialog are global settings. If multiple data fields have been selected in the Gridding Tool Input Tab (i.e. in order to create a multi-banded grid), these settings will affect all fields equally.

Field Data Conditioning

The Field Data Conditioning dialog

Further conditioning controls are available via the Advanced Settings button to the right of the listed input data field. If multiple data fields have been selected in the Gridding Tool Input Tab, the Advanced Settings button can be used to set individual capping and background values for each field by selecting the required field from the pull-down list. Click on the Advanced Settings button to open the Field Data Conditioning dialog:


The Graph view of the Statistics Explorer

The Statistics button at the top of the dialog opens the Statistics Explorer. This tool provides a powerful means of analysing the dataset for geochemical outliers, invalid data ranges, data distribution and more via Graphical, Statistical and Histogram views. This dialog is dynamic and will reflect any invalid data ranges or cap values set in the Field Data Conditioning dialog. This enables the user to check the effect of any conditioning applied to the data range instantaneously.


Invalid Data Values and Ranges

The central part of the Field Data Conditioning dialog allows the specification of invalid data and/or data ranges. All invalid data will be converted to the default null value -1e+032 (-1.0×1032).

Within the Graph and Histogram views of the Statistics Explorer data subsets can be selected using the Rectangle Selection tool.

These subsets can then be viewed using the View Current Selection button.

To return to the previous selection (or entire dataset) use the View Previous Selection button.

To specify an invalid data Value enter the value in the window on the left hand side and use the Cross button to add it to the Invalid Data Value list in the right hand window.

Use the Delete button to remove the highlighted invalid data value from the list.


Specifying individual invalid data values. This is appropriate for removing negative values representing BDL (Below Detection Limit), SNR (Sample Not Received), etc

In instances where there are a number of invalid data values it may be easier to specify an invalid data range. For example, for a dataset that contains -9999, -8888, -5, etc an invalid range from -9999 to -5 could be entered instead.

To specify an invalid data Range enter the lower and upper values in the windows on the left hand side and use the Cross button to add it to the Invalid Data Range list in the right hand window.

Use the Delete button to remove the highlighted invalid data range from the list.


Specifying an invalid data range to remove a range of negative values in the dataset from the gridding process

When multiple bands or fields in a dataset are being gridded at the same time it is possible to set different background values and minimum and maximum cap values for each band in the Field Data Conditioning dialog. If these values are to be the same for each band then set the values in the Grid Conditioning dialog instead.

Note If the invalid data values or invalid data ranges are the same for individual bands these will have to be entered separately for each band. Select a band from the pull-down list in the Grid Conditioning dialog and click on the Advanced Settings button to enter the values. Repeat for all remaining bands.


Gridding Tool Method Tab

Seven gridding methods are provided by Discover. The methods can be selected via the Method tab on the gridding tool dialog. The gridding method chosen will determine the number of additional dialog tabs and control properties that are displayed along the top of the gridding tool.

Located on the Method tab is an option to save the grid parameters or to apply pre-defined parameters.

The available methods are described in more below.

The Load Settings button will present the user with a list of user-defined grid parameters. The grid configuration file GridTool.set, containing these settings, is located in the user configuration folder, by default this will be C:\Program Files\MapInfo\Professional\Discover\Config (refer to Getting Started: Configuring Encom Discover for further information)

The Save Settings button is used to save settings from the existing Create Grid session, such as gridding method and search parameters (it does not save the grid cell size). These settings can therefore be applied to different bands or different datasets. The grid configuration file GridTool.set is located in the user configuration folder, by default this will be C:\Program Files\MapInfo\Professional\Discover\Config (refer to Getting Started: Configuring Encom Discover for further information)

The Load From Existing Grid option is designed to load gridding parameters from an existing grid file. By default a Discover-created grid will have an associated XML configuration file located in the same folder as the parent grid; to load these settings navigate to the associated XML file. Note that this option should only be used on the same dataset, as it will load all geometric settings for the grid such as grid extents and, cell size and band used.


The Method Tab with Minimum Curvature method selected

Minimum Curvature

The Minimum Curvature gridding method is widely used in many branches of science and research. This method creates an interpolated surface similar to a thin, linearly elastic plate passing through each of the data values defined in the input dataset. An important criterion in creating a surface is that it has a minimum amount of bending forced upon it to conform to the data points. The degree of bending is constrained by a ‘tension’ parameter and this can be specified both within the data area and along the edges. Minimum curvature gridding generates the smoothest surface possible while attempting to honour the data as closely as possible. Like all gridding methods, minimum curvature gridding is not an exact interpolation technique and therefore some error may occur between the input data point values and the interpolated surface values.


Minimum Curvature Tab

The Minimum curvature algorithm attempts to fit a surface through all of the data points without putting any abrupt kinks in the surface. Between the fixed observation points, the surface bends according to the Interior tension. This parameter is used to control the amount of distortion on the interior with the higher the tension, the less the distortion. The Boundary tension controls the amount of distortion at the edges. By default, the boundary tension is set to 0.

The minimum curvature method produces a grid by repeatedly applying an equation over the data in an attempt to produce a smoothly varying grid. Iteration is used to describe the number of times the equation is to be applied to the grid. The Maximum iterations number can be specified in the Minimum Curvature tab. The grid node values are recalculated until successive changes in the error between successive iterations are minimised, or the maximum number of iterations is reached.

Kriging

Kriging is a geostatistical gridding method which has proven popular across a variety of industries due to its flexibility and data driven approach to surface interpolation. Kriging is an advanced technique which is based on the assumption that the spatial variability in the measured property of a data set is neither due to totally random nor deterministic constraints. The main advantage of Kriging over simpler interpolation techniques such as IDW (Inverse Distance Weighting), is that it uses a weighting model which is adaptive to the inherent trends in a data set rather than imposing a set of fixed conditions upon them. The process of using Kriging in interpolation can be complex and requires an intimate knowledge of the structure and variability in the data set so that an appropriate sample model and set of gridding properties can be chosen.


Over the past several decades kriging has become a fundamental tool in the field of geostatistics. The method of interpolating a surface using kriging is generally performed as a two stage process:

1. Analyse the input data to establish the spatial predictability of the measured values in the study area. This analysis generally focuses on the spatially correlated component of the data by means of determining the degree of spatial dependence among the sample points. The average degree of spatial dependence among variables is summarised in a plot known as the semi-variogram. The semi-variogram is a concise means of representing the average intersample variation according to sample separation distance and direction. In order to use the sample variance as part of the interpolator in the Kriging process it is necessary to model the semi-variogram in order to define a mathematical function which optimally describes the underlying structure in the data. This process is known as variogram modelling which in itself and can be a very involved and complex task. Once an appropriate model has been chosen it can then be used to estimate the semivariance or weighting at any given sample distance.

2. Interpolation or estimation of values at locations which have not been adequately sampled. This process is known as interpolation ‘kriging’. The simplest technique known as “ordinary kriging” uses a weighted average of the neighbouring samples to estimate the unknown value at a given grid node. The weights are optimized for each node using the variogram model, the distance to the surrounding samples and the inter-sample variance.

The first step in kriging is to construct a variogram (or semivariogram) from the input data which describes the spatial correlation between the sample points. A variogram generally consists of two parts:

• An experimental or sample variogram

• A model variogram (a descriptive function that mathematically models the experimental variogram).

The degree of spatial dependence among sample points is measured by the average semivariance:

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Where h is the distance or lag between sample points, n is the number of samples separated by h and z is the attribute value of interest. The computation of γ(h) is performed in two steps. First pairs of sample points are grouped together by distance. For example, if the distance interval (or lag) is 1000m then pairs of points separated by less than 1000m are grouped together into a 0-1000m lag, samples separated by a distance of between 1000 and 2000m would be grouped into a lag of 1000-200m and so on. Next the average distance h and the average semivariance γ(h) is calculated for each group. If spatial dependence exists among the samples, then pairs of points closer together will have more similar values than pairs that are further apart. The semivariogram is a plot which has the average semivariance γ(h) along the y-axis and the separation distance h along the x-axis.

Experimental and Model Variogram used in kriging

The semivariogram can be broken down into thee main components; the Nugget, Sill and Range.

• Nugget - is the semivariance at a distance of zero and represents the degree of sample repeatability or spatially uncorrelated noise.

• Range – is the spatially correlated portion of the semivariogram that exhibits an increase in the semivariance with distance. Towards the limit of the range the semivariance levels off such that with additional increases in distance it is indistinguishable from one point to the next. This point of flattening is called the sill.

• Sill – is the point at which the semivariance (range) levels off to a relatively constant value.

Once an experimental variogram has been computed, the next step is to define a model variogram. A model variogram is a mathematical function that models the trend in the experimental variogram. Once the model variogram is constructed, it is used to compute the weights which are used in the kriging interpolator. The basic equation used in ordinary kriging can be described as follows:


Where n is the number of points in the data set, fi are the attribute values of these points, and wi are weights assigned to each point. This equation is essentially the same as the equation used for inverse distance weighted interpolation except that rather than using weights based on an arbitrary function of distance, the weights used in kriging are based on the model variogram.

The creation and analysis of the sample and model variograms is done using the Statistics Explorer as discussed later in this chapter.

Selection of Kriging on the method tab opens both the Search Tab and Kriging tab on the gridding tool interface. Kriging uses the same searching mechanism as the Inverse Distance Weighting method.

The gridding tool supports two types of kriging estimation; Point and Block. Point kriging estimates the values of the points at each of the grid nodes. Block kriging on the other hand estimates the average value of points which fall within a rectangular block centred on each of the grid nodes. Because Block kriging estimates the average point value for each block it tends to generate smoother grids. In addition because block kriging uses an average of the input sample points it is considered an imperfect interpolator even when an input sample falls exactly on a grid node. The Block Kriging method provides controls to decimate (or break up) the blocks into a smaller mesh of sub cells, defined by the X and Y increment values. When a decimation factor is applied in Block Kriging the value assigned to each block is determined as the average of the sub cells inside the block rather than the average of the entire block.

In addition to the point and block estimation types the Discover gridding tool supports two methods of Kriging; Ordinary and Simple. Ordinary Kriging focuses on the spatial correlation component between the measured values but ignores drift (drift is a regional trend in the data which exists is addition to spatial correlation between samples). Simple Kriging is similar to Ordinary Kriging with the exception that the weights used do not sum to unity and the average of the entire data set is used in the interpolation of each grid node rather than the local average of points that fall within the Search Distance of the node. Consequently Simple Kriging can be less precise than Ordinary Kriging but generally produces smoother grids.

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Inverse Distance Weighting

Inverse Distance Weighting (IDW) is a universal technique that can be applied to a wide range of spatial data. IDW uses weighted average interpolation to estimate grid cell values and can be used as either an exact or a smoothing interpolator. Each grid cell value in an output surface is calculated using a weighted average of all data point values surrounding the grid cell that lie within a specified search radius.

The IDW method is optimal when the data has a fairly uniform distribution of input points across the area to be gridded, and some degree of smoothing is beneficial; for example soil samples taken over a regular grid. With this type of data, a repeat measurement at a point does not necessarily give the same results as the first measurement. If the input data points are not evenly distributed then using an oriented search ellipse may produce a more representative grid.

Selection of the Inverse Distance Weighting method opens both the Search Tab and Inverse Distance tab.

The weighting value assigned to each point within the search ellipse is determined by the distance from the data point to the grid node being interpolated. The further away a data point lies from the grid node, the less the point value will contribute to the final value assigned to that node. The distance weighting parameters can be adjusted under the Weighting Model controls in the Inverse Distance tab.

A search ellipse of fixed size and orientation can be defined in a similar manner to the Kriging method using the Search Tab (below); a grid cell value is then calculated from the weighted average of all data points that lie within the ellipse centred on that grid cell.

The Inverse Distance tab


Weighting Model

The weighting of an input data point is (by default) inversely proportional to its distance from the grid node (a Power weight model). This can be varied by choosing a different Weight Model on the Inverse Distance tab, and altering the model’s parameters where applicable. The following models are available for selection:

• LinearEach input point’s weight is proportional to its Euclidian distance from the grid node being interpolated. The linear weight model enables the Nugget and Range parameters to be adjusted in order to vary the weight assignments. At distances less than the Nugget distance the weight model will be 1 – i.e. all data will contribute equally. The Range parameter is used to set the outer distance threshold for which the weight model is applied. Any samples which exceed the Range and are less than the Search Distance (Search Tab) will be assigned an equal weight.

• ExponentialEach input point’s weight is proportional to its distance from the grid node being interpolated raised to the specified power. Increasing the power value will cause smaller weights to be assigned to closer points and more distant points to be assigned equal but large weights. Increasing power values will therefore cause each interpolated grid node to more closely approximate the sample values closest to it. As with the Linear model the Nugget and Range properties can be modified to constrain that distance over which the exponential weight model is most effective.

• PowerThe default option, each input point’s weight is proportional to the inverse of its distance to the specified Power from the grid node. Increasing the weighting power reduces the influence distant points have on the calculated value of each grid node. Large power values cause grid cell values to approximate the value of the nearest data point, while smaller power values will result in data values being more evenly distributed among neighbouring grid nodes. The weighting value defaults to 2 (i.e. the weight of any data point is inversely proportional to the square of its distance from the grid cell) which is appropriate for most situations. If required, the weighting value can be altered to any positive value.

• GaussianThe weight assigned to each input value is determined according to a 2D Gaussian function centred on the grid node. The shape and standard deviation of the Gaussian function is proportional to the Range with larger values producing a flatter function and a smoother grid.


Weighting Options

The Elliptical weighting option is only available when the Elliptical Search option is enabled (in the Search Tab). It adjusts the distance weighting function for data points within the search ellipse depending on their relative position with respect to the elliptical shell. Points located on the same elliptical shell will be assigned equivalent weighting even though their distance from the ellipse centroid may be different.

The Density corrections control dynamically adjusts the search algorithm to optimise grid cell interpolation in areas of data clustering. Activating density corrections can help to enhance detail in datasets where sample points are unevenly spaced (e.g. regional geochemistry sampling) and may in some cases produce a smoother or more representative grid. The density correction modifies the weights for each contributing point based on the sample density at that point.

The Exact hit distance is a tolerance distance for assigning actual input data values to coincident grid nodes. As the inverse distance gridding technique is attempting to interpolate a continuous surface through the data, a certain number of grid nodes coincide with the input data points. Where grid nodes and data points coincide, the distance between them is zero, so by default the data value is assigned a weighting of 1.0 and all other data points in the search radius are given a weight value of zero. This means that grid nodes that are coincident with input data points are assigned the value of the coincident data point rather than an interpolated (averaged) value derived from the data points surrounding it.

This effect can produce significant ‘spotting‘ in the output grid, particularly if the data value of the coincident point/grid cell deviates significantly from the points surrounding it. By adjusting the exact hit distance it is possible to increase the tolerance distance in which input data values are assigned to grid nodes. Assigning this value to a high number can produce unacceptable spotting or concentric banding in the output grid, while reducing the value below 1 has little or no effect.

Note If you have enabled the Use nearest neighbours option (in the Search Tab) in conjunction with four search sectors then you will have effectively removed clustering from the input data point distribution. The Density corrections option is not available when the Use nearest neighbours option is enabled.


The Taper controls allow you to apply a taper function to the interpolated value of each grid node based on its distance to the nearest valid sample point. The taper function is applied using a linear weighting model thereby adjusting the expected grid node values towards the background value. Between a distance of zero and the FROM distance the taper function is assigned a constant value of 1 (i.e. no modification is made to the grid node). Between the FROM and TO distance the taper function is applied as a linear weighting between the grid node value and the background value. Beyond the TO distance grid nodes are assigned the background value.

Search Tab

The Kriging and Inverse Distance Weighting methods, when selected, both display the Search tab, along with their individual control tabs. These methods, if not optimised, can quickly becomes unworkable as the number of input data points increases beyond a few thousand. To improve the performance of these algorithms and to ensure these methods are suitable for large datasets, a search radius can be used to restrict the number of input points that contribute to each interpolation. This introduces a number of problems. For example the algorithm may not find a sufficient number of points within the search radius to make a reasonable estimation or, the spatial distribution of the points within the search radius may not be uniform so that the estimation becomes directionally biased.

The Search tab using the IDW gridding method


The Search tab provides controls to resolve these issues by determining the shape, size and orientation of the search ellipse used to locate data points during interpolation. Specifying an appropriate size and orientation for the search ellipse is important. Setting it smaller than the average data spacing may result in a large number of the interpolated grid cells being assigned a null value and therefore displayed as white in the output grid. Conversely, if the search ellipse is set to be too large then significant edge effects or grid artefacts may result around the edge of the grid. The Search tab is subdivided into a number of sections:

Searching

By default Discover uses a circular search with a radius specified via the Search Distance option. If the node cannot be estimated from the points located within the search radius then the search radius can be incrementally increased and the searching repeated using Search Expansions. The increased radius is likely to encompass more input points and consequently the node may be able to be interpolated. At each stage the actual search radius used will be equal to the stage number multiplied by the initial search radius. The number of allowable increments is limited because after a while this process becomes self defeating and it is wiser to specify a larger initial search radius.

To optimise performance, choose an initial search radius that is likely to encompass the minimum number of required input points most of the time. It can sometimes be very difficult to make this decision but the tool will always make a suggestion to get started with.

If the spatial distribution of the data points is not uniform (or not uniformly random) then the use of search expansions may not be enough to populate the grid successfully. For example, a dataset may have regional data located on two kilometre centres and local data in parts of the study area on 100 metre centres. To produce a suitable grid of the whole region that characterises the detail in the high resolution areas would require small search radius in these areas and a large search radius elsewhere.

The solution is to use additional refinement Grid Passes which grid the data multiple times - once for each pass - at increasingly higher resolution. The gridded results from each pass are then used as additional input data for the next pass. The grid cell size and search parameters are scaled up by a factor of two for each additional grid pass – for example if you use three additional passes then the first pass scales up these parameters by a factor of eight, the second by a factor of 4, the third by a factor of two. The final pass grids the data at the requested resolution with the specified searching parameters.


Anisotropy

By default the search radius is isotropic creating a circular search area. However directional bias can be applied by enabling an Elliptical Search.

The dimensions of the search ellipse can be controlled by specifying the length of the major and minor axes. The major axis is defined by the Search Distance value in the Searching section (above), whilst the minor axis is governed by the Minor search distance option. The Major axis Orientation control determines the rotation angle of the major axis.

If elliptical searching is used with the Inverse Distance Weighting method, it also allows the use of the Elliptical weighting option under the Inverse Distance Weighting tab. This option modifies the data point weighting so that they are isotropic with respect to angle within the search ellipse – in other words it removes the directional bias from the weighting

Sample Selection

Input points ‘close’ to the grid node may not be uniformly distributed– e.g. they may all be on one side of it. This will introduce a directional bias into the estimation. This can be resolved by using search sectors.

Discover provides options for specifying 1, 2 or 4 search sectors. By adjusting the Number of search sectors and Minimum points required (in each sector) the appearance and smoothness of the output grid can be varied. If any of the sectors contain fewer than the minimum number of specified points, the interpolated grid cell value for that node is assigned a null value.

If four sectors are used then each covers 90 degrees of arc (centred about NE, NW, SE, SW). If two sectors are used then each covers 180 degrees of arc (centred about North, South). Using only one search sector effectively turns the option off.

Using 2 or 4 search sectors can significantly improve the appearance of a grid if the input data has been collected on widely spaced lines. Using a one sector search ellipse may result in grid node values being estimated from data points from a single direction. This might generate unrealistic or sharp slopes between the lines producing a rough or stepped grid. Using a two or four sector search with an appropriate search distance should generally eliminate or reduce this effect. Experiment with the use of search sectors and examine the difference these can have on the output grid.

Specifying the Use nearest neighbours option enables you to use only the closest Maximum number of samples found within each search sector in each estimation. Contributions from other points within the search radius are ignored.


The Use nearest neighbours option controls the Maximum number of samples that are used in each sector when interpolating each grid node value. When this option is selected Discover uses the closest points (up to the maximum specified in each sector) to interpolate each grid cell. Any excess data points within the search ellipse are ignored in the calculation.

Gridding Rule

Enabling the Customise gridding rule option allows a node to be gridded only if a specified minimum number of sample points are located in at least a specified minimum number of sectors. If a node fails to meet this rule, it will be assigned a null value.

Spatial Neighbour

This method is similar to the Inverse Distance Weighting method described above but does not use the search radius to interpolate data values from surrounding cells. For each grid cell, neighbouring input points are located based on a ‘spatial neighbours’ selection criterion. The value of the computed grid cell is the average of the neighbours, weighted such that the closer the neighbouring point, the greater the influence than points further away.

Search criteria are only radial in this method but the distance and applied weighting can be specified in the Spatial Neighbour tab displayed when this gridding method is selected.

Spatial Neighbour weighting and search specification tab


Triangulation

The Triangulation method produces a regular gridded surface through a set of data points by using an optimised Delaunay triangulation algorithm. The triangular mesh is created by drawing lines between adjacent input data points and forming an irregular network such that no triangle edges are intersected by other triangles. A regular grid is then computed from the triangular irregular network and grid cell values computed using a natural neighbour interpolation process. As the original data are used to define the triangles, this method is very useful for situations where the data must be honoured very closely (e.g. elevation data in a digital terrain model).

The triangulation method is best applied to data that is evenly distributed over the gridded area. If there are large areas of sparse or missing data distinct triangular facets may appear in the output grid. As triangulation uses all the input data to construct the triangular mesh, the only parameter that needs to be adjusted is the grid cell size. Grid cell size can be adjusted to an appropriate value for the dataset.

Gridding tool dialog with Triangulation Gridding method selected

Density Grid

The Density gridding method produces a grid which records a measure of the point density at each grid node. The density at each grid node is determined independently using an estimator function. Two estimators are available:

• Radial Density Estimator

• Kernel Density Estimator (KDE)


The Radial Density Estimator method returns a true measure of the point density at each grid node (measured as the number of samples per area unit – usually metres). It is a simple method that counts the number of input samples within a specified radius of the grid node position and then normalizes that count by the area of the search.

The Kernel Density Estimator method is a non-parametric density estimator. It uses a similar approach but it weights the input samples by a kernel function that is normally a function of the normalized distance of the sample to the grid node. To achieve a good result with the KDE function it is more important to choose an appropriate search radius – sometimes referred to as the bandwidth – than to choose an appropriate kernel function. If the bandwidth is too small the density will be under-smoothed whereas if the bandwidth is too large the density will be over-smoothed and lacking in resolution.

Given a kernel function K and a search radius (or bandwidth) h, the estimated density at any point x is given by –

where n is the number of samples. The following kernel functions are supported:

Kernel K(u)Uniform

Triangle

Epanechnikov

Quartic

Triweight

Gaussian

))((1)(ˆ1∑=

−=

n

i hixxK

nxf

)1(21

≤uI

)1()1( ≤− uIu

)1()1(43 2 ≤− uIu

)1()1(1615 22 ≤− uIu

)1()1(3235 32 ≤− uIu

)21exp(

21 2u−π


If you have taken multiple samples at each input data location and this information is recorded in the input data then you can use this information to bias the density estimation. To enable this option, check the Interpret selected data channel as a count frequency box and on the Gridding Tool Input Tab ensure the frequency or count field is selected as the input data field.

Density Grid Tab

Distance Grid

The Distance gridding method produces a grid which records the minimum distance to the input data features at every grid node. A distance envelope can be specified to clip the grid at a maximum distance from the nearest feature. Any grid node that is outside this envelope will be assigned a null value.

When the input data is loaded it is classified as either point data or polyline data depending on the source of the data and the type of object that was loaded. By default the method will consider all input data as point locations. Optionally, you can add to this the input polyline data. In this case the method will also check the perpendicular distance to the nearest polyline in addition to looking at all point data.

Cosinus)1()

2cos(

4≤uIππ


Distance Tab

In the examples below the first grid has been computed considering all the input data as point locations. The second grid has added to this the polyline information. In both cases a distance envelope has been applied.

Distance Grid points only Distance Grid points and polylines

Gridding Tool Geometry Tab

This tab controls the main parameters for determining the geometry of the output grid. The Cell Parameters control determines the size of each grid cell in the output image and is measured in the same data units as the input tab file. For most geographic data these units are in metres; however Discover supports all of the MapInfo units of measurement. During the loading process, Discover automatically computes an optimised grid cell size based on the distribution and density of the input data. This cell size can be modified and Discover only uses square grid cell dimensions.


When a large dataset is loaded the Auto Apply box is disabled and the Compute Best Parameters button is active. Use this button to calculate an optimal grid cell size.

The extents of the Data coverage to be gridded can be modified by entering new co-ordinates into the Min and Max X and Y columns. The full extents of the original data coverage are displayed by default. If the coordinates have been modified select the Reset to Input Extents button to return to the original data coverage.

The Grid bounds parameters control the boundary extents of the output grid and can be used to reduce the size of the output grid if required. The number of Rows and Columns in the output grid is also displayed. These values are calculated from the grid extents and cell size and cannot be edited.

The Grid Geometry tab indicating the cell size, extent and number of rows and columns

Note When creating a surface, the grid cell size selected is important. As a general rule of thumb the grid cell size should not be made smaller than approximately one fifth of the average data spacing. Reducing the grid cell size beyond this limit may cause the grids appearance to become smoother but can also introduce unwanted irregularities in the output image. Assigning an excessively small grid cell size will also increase computation time and file size. Discover suggests an optimal grid cell size for the data but experiment with alternative values.


Gridding Tool Output Tab

The Output tab provides a number of controls for saving the gridded image. The left side of the dialog provides a summary report for the grid process and lists the primary gridding parameters chosen. This information may be copied to the windows clipboard by selecting the information with the mouse and using the Windows Copy and Paste commands. This may be useful for reporting or archive purposes.

The Grid Output showing summary information and clipping options

Below the summary box is a pull-down list containing the Discover supported grid formats. Discover currently creates grids in ER Mapper (.ERS), Geosoft (.GRD) and Surfer Binary (.GRD) uncompressed grid formats. To save a grid, select the appropriate format from the list. Click the Save button. The output grid file is assigned a default name and will be saved in the same directory as the input data. It is possible to alter the file name and directory path by clicking on the small button at the right end of the path name box. The Output tab is accessible at any stage during the gridding process so it is not necessary to wait for the preview window to complete drawing before saving the final grid.

The Smooth grid control allows the appearance of the output image to be smoothed by applying a Gaussian smoothing filter to the grid. In most situations, enabling the smooth grid function removes high frequency noise in the grid and enhances the appearance of your image.


The Clip control provides a number of options for clipping the extents of the interpolated grid, so that it more closely approximates the distribution of the input data. Enabling this option can improve the appearance of the output grid for irregular input data where the gridding method (usually Triangulation or Minimum Curvature) has interpolated the grid over large gaps within the data. Options available include:

• Creating a Buffer around the input data at a user-specified distance. The gridded data outside the buffer is then removed.

• The Near value of the Near/Far option is the distance the grid is to be clipped back to from the convex hull of the data points. The Far distance is the distance between the points to interpolate between. Areas in the grid which lie between data points greater than the Far distance value grid will be displayed as null or “white”.

• The Convex Hull option clips the output grid to the smallest convex region/polygon enclosing the dataset. This convex region is found conceptually by stretching a rubber band around the points so that all of the points lie within the band. The convex region can be expanded by a specified Buffer value.

• The Concave Hull option starts with a Convex Hull region, and then removes/erodes triangles on its edge that have an outward facing angle greater than a defined tolerance (specified under the Options button). This new concave region can then be expanded by a specified Buffer value.


Multiple field gridding output options

If multiple fields have been selected for gridding then three output options are available:

• Separate grids - each selected field is created as a separate grid which is named using the original source table with the field name extension. E.g. Geochem_Cu, Geochem_Pb, etc.

• Multi-banded grid - multiple fields are gridded and saved to a single ERMapper Multi-banded grid.

• Create RGB Image - if three fields are selected for gridding they can be saved as an RGB image. Each field is saved as a red, green or blue channel in the resulting image. The RGB grid is first loaded into the Surfaces>Grid Utilities>Create RGB Grid dialog before the final RGB GeoTiff image is created.

When the Gridding Tool parameters have been selected and the grid surface is completed, press the Save button. This button closes the Gridding Tool dialog, saves the grid surface into the specified file and updates the original map window with the surface grid. The surface grid is displayed using the same look-up table as selected in the Gridding Tool dialog prior to saving.


Statistics Explorer

The Statistics Explorer is a series of dialogs that enables you to examine any dataset both statistically and spatially.

To access the Statistics Explorer one or more fields must be selected and applied within the Gridding Tool. It can be accessed from two locations:

• the Statistics Explorer button on the Gridding Tool Input Tab

• the Variogram button on the Kriging tab. Accessing the Statistics Explorer through the Kriging tab allows the creation and editing of Model Variograms.

The components of the Statistics Explorer window


The Statistics Explorer window is divided into two main sections; the upper Spreadsheet window and the lower Property Page window. The contents of these depend on the view selected; the Statistics Explorer has four views, selectable from drop list at the top left of the window. These present graphical and statistical information using different Property Pages, which can be controlled using the Property Page tabs in the middle of the window. These views are:

• The Univariate view examines a single field in the input data and presents basic summary statistics and histogram analysis.

• The Bivariate view examines any two fields in the input data and presents scattergram plots and basic summary statistics.

• The Spatial view plots the data using its spatial X, Y and Z coordinates and presents basic summary statistics.

• The Variogram view computes a variogram grid and displays directional semi-variogram data. This allows the creation of sample variograms, and creation and editing of model variograms.

The Statistics Explorer allows data to be selected in the spreadsheet or any of the univariate, bivariate or spatial views using the Selection Tools at the base of the window. The explorer can then ‘collapse’ the dataset to the current selection, and display the statistics for this new data subset.

Spreadsheet

The Spreadsheet comprises the top half of the Statistics Explorer dialog, and displays the records for the currently viewed selection.

It uses the following colour codes to highlight records:

• The currently selected data points are highlighted red

• The currently selected data point is highlighted purple

• Invalid data is highlighted orange (e.g. coincident data)

• The current key and ancillary fields are highlighted purple


The spreadsheet pop-up menu can be accessed by right clicking on any column header. This provides a number of column resizing options (including the various ‘Fit to’ options). Alternatively, columns and rows can be resized by clicking on their boundaries and dragging.

The Spreadsheet pop-up menu

The spreadsheet can also be sorted by any column using the Sort menu options. The Statistics option returns a basic statistical summary of any field.

The statistics summary for an arsenic field

Data points can be selected from the spreadsheet (if valid for the current view) by clicking on the row header; use the CTRL and SHIFT keys to unselect stations and make multiple selections. A range of cells can be also be selected by clicking and dragging the mouse. These selection operations are treated exactly the same way as graphical selections and the undo/redo operations can be applied.


The key field (whilst in univariate mode) or the ancillary field (whilst in bivariate mode) can be changed by double clicking on the field header in the spreadsheet.

Zoom, Selection and Display Controls

Each of the view types incorporates a number of property pages, discussed further under the relevant view sections. Depending on the view type, some or all of the following controls may be available within a property page window:

Zoom controls

The Zoom controls toolbar

• Use the three buttons in the middle to Zoom In, Zoom Out and Pan.

• The Restrict Zoom button on the left restricts zooming and panning to the horizontal dimension only.

• The Fit to Data button on the right cancels any zoom and returns to the default view showing all data.

Selection Tools

The Selection controls toolbar

When a single data point is selected in any graph (using the Pointer tool, see Zoom, Selection and Display Controls) the spreadsheet will scroll to the appropriate record.

The Selection tools provide a powerful data selection capability. The Pointer button displays a cursor which can dragged through the graph. It may be displayed as either a vertical bar or a cross hair depending on graph type. In all cases, the pointer ‘snaps’ to the closest station and this station is then highlighted purple in the spreadsheet.

Data can also be selected using Rectangle or Polygon selection, although the polygon selection is not available in all graphs. Selected stations are coloured red unless colour modulation is enabled in which case they are coloured black. Each selection operation can either select the enclosed stations (include option) or unselect the enclosed stations (exclude); this is toggled using the Include/Exclude button.


Display Modulation

The graph can be also be Colour and/or Size Modulated by any field in the dataset. Select the required fields from the drop lists at the base of the graph. To cancel colour or size modulation, select <None>. A simple pseudocolour look-up table is used and a linear colour stretch is employed.

Subsetting

Univariate

The univariate view examines a single field in the input data and presents basic summary statistics and histogram analysis. It incorporates three property pages:

• A Scattergram graph of the data point index verses key field

• Statistical information for the key field.

• A Histogram of the key field. When this is displayed, the spreadsheet will show a detailed breakdown of the histogram data.

The univariate view requires a key field to be defined. This field is selected from the second drop list at the top of the dialog. The key field can be changed at any time to examine any field in the dataset.

Each selection operation is placed onto a stack which allows you to Undo and Redo operations. Buttons are also provides to Unselect All and Select All. The selection can also be Inverted.

Making a selection within a graph (which supports selections) or the spreadsheet view will activate the Collapse button at the top of the Statistics Explorer window.

This button extracts the selected data points from the dataset to create a new subset. The spreadsheet and graph views will be redrawn to focus on this subset. Only the subset will be considered in any statistical computations or graphs. Further selections can be made to examine the data in greater detail. The Expand button allows a previous level/subset to be redisplayed. If this button is disabled then the view has returned to the original dataset.


Univariate graph display

The Graph page plots the key field versus station index. Graph controls are detailed in Zoom, Selection and Display Controls above.

The properties of the graph can be obtained by double clicking on an appropriate area of the graph. For example, click in the bottom and left margins to obtain properties of the X and Y axes. This property page enables you to change the axis extents and change the axis mapping between linear and logarithmic. When using logarithmic axes, you must elect to leave some data space surrounding zero as linear.


Specifying an axis range

Statistics of the chosen field

The Statistics page presents basic summary statistics for the key field, as detailed below:

Note These axes property pages are not available for univariate or spatial graphs.


Sample Count The total number of samples in the dataset.

Valid Sample Count The total number of valid (non-null/selected) samples in the dataset.

Invalid Sample Count The total number of invalid (null/unselected) samples in the dataset.

Minimum The minimum value of all valid samples.

Maximum The maximum value of all valid samples

Mean The mean (average) value of all valid samples.

Variance The variance of all valid samples.

Standard Deviation The standard deviation of all valid samples.

S/N Ratio The signal to noise ratio of all valid samples.

Coefficient of skewness The skewness of all valid samples.

Skew direction The skew direction (positive/negative) of all valid samples.

Median The value of the centre value in the sorted dataset.

Mode The most frequently occurring valid value in the dataset.

Lower quartile The value of the dataset at the 25 percent quartile.

Upper quartile The value of the dataset at the 75 percent quartile.

Interquartile range The range of the data between the lower and upper quartiles.


Histogram distribution of the selected field

The Histogram page presents an ‘equal width’ histogram of the key field. An equal width histogram is one built by dividing the valid data range into a large number of equal width bins and then computing the frequency of occurrence of key field values in each bin.

To be effective a large number of bins are used and these are grouped together depending on the scale at which the histogram is viewed. When multiple bins are being grouped together each consolidated bin is drawn with a back border. When zoomed in sufficiently to see individual bins, no black border is drawn. Also, the thickness of the bin is no longer equal to the assigned min/max values of the bin; it now relates to the actual min/max values of the data assigned to the bin.

The cumulative histogram is also displayed as a heavy green line. This indicates the percentage of data that is below the current value at any point. The upper and lower quartiles are displayed against the X and Y axes as dotted lines.

The spreadsheet displays the bin information including the bin data range, number of samples in each bin and the range of the actual data assigned to the bin. It also displays the cumulative histogram values.

The Zoom, Selection and Display Controls work normally in this graph. The selections are indicated as a percentage of stations selected in each bin. This is displayed as a red base. Note that no selections can be made from the spreadsheet in this mode.


Bivariate

Display of Bivariate data distribution with Key and Ancillary selection fields indicated

The Bivariate view requires the user to define two input fields – the key (horizontal) field and the ancillary (vertical) field. Make these selections from the drop lists at the top of the explorer (indicated in screenshot above).

Two property pages are presented. The Graph page shows a scattergram of the ancillary field plotted against the key field. The Statistics page presents summary statistics for the bivariate distribution as well as a spreadsheet of the conditional expectation. You can copy and paste from this spreadsheet into Microsoft Excel.


The Graph page displays a linear regression as a blue line. A conditional expectation curve is also displayed as a green line. It also displays a quantile vs. quantile (q-q) curve as a purple line from 5% to 95% at steps of 5%.

For both pages, the Spreadsheet displays the complete dataset. A full range of selection tools are available both graphically and in the spreadsheet.

The following statistical definitions are used:

Sample Count The minimum number of samples in both fields

Valid Sample Count The total number of valid (non-null/selected) samples in one or both fields.

Invalid Sample Count The total number of invalid (null/unselected) samples in one or both fields.

Valid data range The range of valid common samples in the key and ancillary fields (X,Y).

Minimum The minimum value of all valid samples.

Maximum The maximum value of all valid samples.

Mean The mean (average) value of all valid samples.

Covariance Sum of squares of product of the difference between the field mean and each sample

Correlation coefficient Covariance normalized by the product of the fields standard deviations.

Inertia Half the sum of squares of difference between the two fields

Rank coefficient Spearman rank coefficient

Regression Linear regression fit to all valid samples

Intercept Value of the ancillary field at the origin.

Slope Slope of the ancillary field versus the key field.

Conditional Expectation Expected value of V at any U.


Bivariate statistical data ranges and distribution

Spatial

The Spatial view does not require the user to define any fields (unless the View Extraction option on the Statistics page is used; see below). The data will be automatically plotted using its spatial coordinates in an isotropic view. If the data has less than two spatial dimensions no spatial view will be available.

A Graph page showing the spatial plot is presented. All Zoom, Selection and Display Controls are available. Data points can be colour or size modulated.


Displaying the Spatial distribution of the data

The Spatial Statistics pages


The Statistics page displays basic summary statistics for the spatial fields. It also has a Regular spatial extraction export option. This creates a new dataset using multiple regular sized cells covering the entire spatial extents of the existing dataset. The size of these cells are defined using the X and Y Extent windows. The Region Overlap control allows cells to overlap adjacent cells by up to 50%.

Regular spatial extraction requires the prior specification of a Key field in order to calculate summary statistics for each new output cell. The output dataset can be viewed using the View extraction button, which opens it in a new instance of the Statistics Explorer. The Save Extraction button allows this output dataset to be saved as a multi-banded ERMapper grid file.

Variogram

The Variogram view requires the user to define a key field which will be used in tandem with the spatial coordinates to compute a sample variogram. If the data has less than two spatial dimensions no variogram view will be available.

A variogram shows the degree of correlation between data in a spatial dataset in different directions and at different distances.

It can take a long time to compute a variogram and in most cases it will not be possible to compute the complete variogram for the entire data set unless it is relatively small (< 10,000 samples). Variogram computations are restricted by:

• Capping the maximum range (distance between points) that will be considered

• Capping the number of input samples that will be considered.


Display of the calculated variogram

A default spatial variogram is computed using parameters that should ensure that the computation time is of the order of a few seconds. Thereafter the range and maximum sample number can be modified and the variogram can be recomputed by hitting the Recompute Variogram button. Note that if the maximum number of samples is set to minus one, then all samples will be computed. It is not advised to include all samples in the data set if it exceeds 10,000 samples as the computation time required to build the variogram could be extremely long. If the number of samples is restricted the algorithm will look at a sub-set of samples that are evenly distributed spatially within the dataset. In many cases it is desirable to increase the range and increase the maximum number of samples to improve the statistical reliability of the variogram.


This procedure generates a radial variogram grid (lower left). The directional variogram can then be quickly extracted from this grid. The directional variogram is plotted on the right and the source data is shown in the spreadsheet. Only the zoom tools are available in this graph (no data selection is possible).

The plot on the left shows the variogram grid. The red sectors represent the area of the grid that was used to extract the directional variogram. This area is controlled via Direction (0 to 360 degree clockwise from North) and Width (degrees of arc) controls. If the width is 180 degrees then you have obtained the omni-directional variogram and direction is irrelevant. Otherwise, you will obtain a direction dependent variogram. You can change the direction of the variogram from the Direction spin buttons or simply click and drag you mouse across the variogram grid plot. The width can only be changed via the Width spin control.

The variogram records several parameters including the moment of inertia (semi-variogram), covariance and pair count. Both the variogram grid plot and the directional variogram plot display the parameter selected in the Display drop list.

Model Variograms

If the Statistics Explorer has been opened via the Variogram button within the Kriging tab of the Gridding Tool, a Model Variogram also can be created, edited and displayed. In this case an option is added to the Sample page to show the model variogram curve in addition to the sample variogram curve.

A Model property page is also available to manipulate the model variogram. The model variogram will be automatically initialized to a reasonable model fitting the data. You can press the Initialise Model button at any time to reset the model to this default.

The model is plotted to a range controlled via the range edit parameter. By default this is equal to the sample variogram range.

The model variogram is displayed as a grid and also as a directional extraction – just like the sample variogram. The sample variogram curve can be plotted for comparison. As before, the extraction direction can be controlled via the edit buttons or by dragging the cursor across the variogram grid display.

In the upper right the model nests are displayed. Each nest corresponds to semivariogram model. Individual nests can be edited, added, cloned and deleted via the buttons on the right. Alternatively double clicking on a nest in the list allows editing.


Displaying the sample and model variograms

Editing or adding a nest presents the following dialog; if adding a new nest the dialog is presented as a wizard.

Select the Model Type from the range available


The Model Type page allows you to change or select an appropriate model for the nest. A description of the model is presented. The coordinates displayed for the model are not representative of the actual model coordinates.

Controlling the parameters of the variogram

The Parameters page allows the editing of the model parameters. At the top right is a drop-list of model types.

The graph presents the sample variogram, the model variogram excluding the current nest you are editing or adding, the current nest and the final model variogram including the current nest. The model parameters are presented below the graph and can be directly edited. Also, most model parameters can be edited graphically by dragging the blue tags that are presented on the graph axes. For example, with the spherical model the left vertical axes allows the editing of the sill and the bottom horizontal axis allows range to be edited.

The sample variogram grid is displayed in the bottom left. Drag the cursor in this graph to edit the direction of the model variogram. This will also change the direction for the sample variogram extraction. Note that the width of the extraction is equal to the width of the extraction on the main ‘Sample’ page and cannot be modified here.


Editing the variogram nest

The Anisotropy tab controls the range of the model along two axes – the major and minor axes. The direction of the major axis is shown on the nest grid preview on the left. The final model preview is shown on the right.

The major axis range will be equal to the range established on the ‘Parameters’ page. The minor axis range can be used to introduce anisotropy to the model. If the minor axis range is equal to the major axis range then the model is isotropic. If it is larger than the major axis range then the model will have a smaller contribution in the minor axis direction.

The principal parameters of each nest can be altered graphically via the ‘model’ page. Select the nest from the model list and manipulate the principal parameters via the blue edit tags in the variogram plot.

Large Multi-file Triangulation

Surfaces>Create Grid>Large Multi-file Triangulation

The Large Multi-file Triangulation tool is a powerful grid interpolator which can construct gridded surfaces from extremely large point datasets. Interpolated grids can be created from a single input file or from multiple input files of point data in


ASCII (.txt), MapInfo .TAB or ASPRS .LAS format.

The Large Multi-file triangulation tool is best suited to gridding very large, closely spaced point datasets, such as those commonly acquired by airborne Light Detection and Ranging (LIDAR) data surveys. This method of interpolation works best with relatively even spaced points that cover semi rectangular survey areas containing minimal internal holes or areas of missing data. For standard sized point datasets or situations where alternative interpolation methods are required the Interactive gridding tool is a more flexible and suitable choice.

• When to Use Large Multi-file Triangulation

• Using the Large Multi-file Triangulation Tool

• Input Data Files

• Interpolation Settings

When to Use Large Multi-file Triangulation

As a rule of thumb if the number of points in the input dataset exceeds 3 million points or the number of cells in the output grid greater than 6000 columns x 6000 rows (360,000,000 cells) then the Large Multi-file triangulation tool is the appropriate tool to use. For all datasets which fall below this size threshold (even ones that require triangulation) the interactive gridding tool would be the best tool to use. For practical purposes the maximum size of the combined input dataset the Large Multi-file triangulation tool can process is 1 billion points and the maximum size of the output grid(s) is 1 terabyte.

Using the Large Multi-file Triangulation Tool

• Running the Triangulation

• The Triangulation Process

• Re-running the Triangulation


Running the Triangulation

For more information about the settings available from dialog boxes, see Interpolation Settings.

1. On the Surfaces menu, point to Create Grid, and click Large Multi-file Triangulation.

The Large Multi-file Triagulation dialog box is displayed.

2. Under Input, to select input files that are stored in a single directory:

• Press the Browse for files button on the top right of the dialog. On the open file dialog adjust the file type filter at the bottom to the appropriate type (*.TAB, *. ASCII, *.LAS) and select the files to grid.

Or for input files that are stored in a multiple directories:

• Press the Browse for folder button, second button down on the top right of the dialog. On the Select file format dialog which appears choose the file type filter which is appropriate for the type of input data, press Ok and select the top level directory from which to search for files to grid.

3. To assign the column field order for the input dataset press the Column order button. On the Select data fields dialog choose the field for the X coordinate and Y coordinate. If the input dataset(s) are LIDAR LAS files these fields will be automatically assigned. From the field list select the data column(s) you wish to grid.

4. Assign the appropriate projection for the input data files by pressing the Choose Projection button in the bottom right of the dialog.

Note If you are unfamiliar with the distribution of statistics of your input files you can examine the spatial statistics of any of the selected input data files using the Statistics Explorer. To launch the Statistics Explorer select an input file and then press the Statistics Explorer button (on right of file format dialog).

5. If desired modify the name that has been assigned in the Group alias property for the group in the input manager grid control by double-clicking in the cell and typing in a new name.


6. To change the properties of a group of input files, first select the group you wish to modify in the input manager and then press the File format button on the right of the dialog. On the format dialog you can add or remove files from a group as well as change the input data format and projection.

7. If you are familiar with the spatial distribution and coverage of the input data enable the Define cell size control and change the cell size from <Auto> to an appropriate value that is suitable for the input data and for your analytical needs. Should you need assistance in choosing an appropriate cell size you can press the Compute cell size button and the software will attempt to analyse a small subset of the data and estimate an appropriate value. However it is generally recommended that if you are not sure what cell size to assign for the output grid that you leave the Define cell size disabled so the software can compute an appropriate value once it has completed an analysis of the data distribution.

8. Optional steps:

• Press the Data conditioning button to configure any null values or data ranges you may wish to exclude during the gridding process.

• Define the grid geometry by specifying the Origin X and Origin Y coordinate of the lower left corner of the output grid as well as the grid dimension in rows and columns.

• Press the Advanced settings button and modify the Options as necessary. You may need to set the Temp directory path to an alternative drive which has plenty of free space available to store an entire copy of the input dataset if it is very large. You may also adjust the Scan data extents control to perform a quick scan of the input data as well as constrain the maximum memory that will be used by the software during gridding. Adjust the triangulation parameters as necessary to eliminate unwanted triangles and preserve natural holes and islands in the input data.

9. Press the Save file button and select an appropriate file path for the final grid file(s). Ensure that you select a location with plenty of free space to store the output files. It is recommended that for large datasets the output grid(s) are stored on a separate disk drive to the input data.

10. Press the Projection button and choose an appropriate projection for the output grid file. It is recommended that the projection of the output grid file is set to the same projection as the input file(s).

11. (Optional) Disable the Auto open output file(s) if you do not want the output grid file(s) to be automatically opened into MapInfo on completion of the gridding process.


The Triangulation Process

12. Press the Process button to commence gridding.

Phase 1. A quick analyse of your computer is performed to establish the amount of RAM and free disk space available and all input files are validated.

Phase 2. A small representative subset of data is loaded from the first input file and examined to determine spatial statistics

Phase 3. The software scans through each input data file to determine the data extents and spatial distribution statistics. Some data may be skipped during this phase if the Scan data extents property is set to any value other than complete

Phase 4. Preliminary gridding parameters and temporary data storage requirements are estimated from the spatial statistics obtained during the initial data scan (phase 3)

Phase 5. Gridding properties and memory requirements are established

Phase 6. The software performs a second scan through the entire input data set and spatially sorts the points, cleanses them of unwanted or null readings and reprojects the coordinates into the output grid coordinate system if required.

Phase 7. The spatially sorted input data is triangulated and the interpolated values are written to the output file.

Phase 8. The triangulated grid(s) are finalized and corresponding header information and.TAB files are written to disk. All temporary files an allocated memory is then released


Re-running the Triangulation

Input Data Files

The main features of input files that can be read are:

• One or more input files are supported.

• A range of commonly used input formats can be read including .TAB, .LAS, CSV, space and tab delimited text files, and general text files.

• Input files can be located in a single directory or hierarchically in multiple directories.

• Input files can be specified in groups. A group of input files share common properties such as format (i.e. file structure) and projection. If the file format or projection of any of the input files is different they should be separated into their own group.

Input file formats

Input files can be provided in any of the following formats:

• MapInfo .TABThe TAB reader can read simple MapInfo .TAB files which contain mapped objects. The coordinate and projection information is extracted from the mapped objects and X,Y point coordinates are obtained for every node of simple or multi-part objects. The data field information which is used for interpolation can be obtained from any corresponding attribute field in the file.

At the completion of gridding a control file containing a complete set of parameters used by the gridding engine are saved to a text file in the same location as the output grid. The control file is created with the same name as the output grid file and has .final.txt appended to the end.

Should you wish to create another grid using a different field from the same input data or recreate the same grid with slightly modify settings you can reload the saved control file. To do this first open the Large multi-file triangulation tool. Next press the load control file button (the last button at the top right of input manager). When the control file is successfully loaded you can modify the settings as necessary and then press process to create the grid.


• ASPRS .LASLAS is an industry standard public format used for the interchange of LIDAR data. The file format is defined and maintained by the ASPRS organisation (www.asprs.org). Discover supports versions 1.0, 1.1 and 1.2 of the LAS specification and can extract "Z" (elevation) as well as RGB (red, green, blue) and intensity information.

• Generic ASCII or text filesASCII files with a file extension of *.TXT, *.ASC, *.XYZ may be loaded directly into the gridding tool.

ASCII data readers

There are two readers available for ASCII data:

Space, Comma or Tab Delimited (Fast) - is the faster of the two text readers but it expects data to be stored in columns with a Space, Tab or Comma separating each row value. The reader can skip multiple header lines at the start of a file but once it starts reading data it expects the remainder of the file to be clean and void of inline comments or other formatting changes. For well structured, clean data this is the best method to use.

Generic Text (Slow) - is a general text reader which handles a wider range of delimiters. It can also detect and skip inline comments or adjust to formatting changes in the input file(s).

Input file groups

• Projection information can be assigned to each group of input files. The projection information specified must correspond to the spatial reference the data is stored in. If no projection is assigned to the input data it will be assigned the projection of the output grid.

• You may modify the group alias name for each group of input files to help distinguish them in situations where a lot of groups have been added.

Interpolation Settings

• Data Conditioning

• Gridding Properties

• Options

• Triangulation Parameters

http://www.asprs.org


• Output Grid

Data Conditioning

Data conditioning is a pre-processing operation which is applied to the input data prior to gridding. It allows you to define a NULL value as well as ranges of data, with upper and lower caps, in order to exclude them from the gridding process. The data conditioning process only applies to valid input data. Should any of the fields in the input data set for a given point (i.e. X, Y or the field values) have a NULL (or missing) value then the entire point is discarded. For more information, see Data Conditioning.

Gridding Properties

The gridding method used by the Large Multi-file Triangulation tool, as the name implies, is triangulation, or to be more precise Delaunay triangulation with linear interpolation. The method works by first triangulating the input data into a TIN mesh. It then calculates a value at the centre of each cell in the output grid using linear interpolation from the triangle that overlaps with coordinate of the centre of each grid cell. In order for the software work with huge datasets that could potentially contain billions of triangles on PC's with limited available memory, the input data is scanned, spatially sorted and divided into tiles. Each of the tiles is then triangulated and the resulting TIN mesh is either stored in memory or if there is insufficient memory available it is stored on disk in temporary files. Once the dataset has been triangulated into a TIN mesh the output grid is built by interpolating cell values from the triangles.

Because the triangulation process is relatively autonomous it is possible to leave the gridding properties set to their default settings and the software will attempt to automatically compute an appropriate set of parameters for the output grid by examining the field and spatial statistics of the input file(s). If you are unfamiliar with the distribution or range of the input data sets then leaving the gridding properties on their default settings is recommended.

If you are familiar with the input dataset and know in advance what the spatial extents and distribution of the data is like and you have a good understanding of the band or field range then you can manually adjust the gridding properties to best suite the input and output data requirements.


Define cell size

This property controls the size (or resolution) of each cell in the output grid file. The size is measured in the spatial units of the output grid coordinate system. The default cell value is "Auto" which indicates that the software will attempt to compute an appropriate cell size for the output grid by analysing the spatial statistics of the input data. Providing the source data is regularly spaced and evenly distributed across the entire survey area the automatic cell size estimation algorithm will choose a reasonable cell size. However if the data distribution is clustered or skewed then it is strongly recommended that you set the cell size to an appropriate value manually.

As a general rule of thumb the output grid cell size should not be set to a value that is less than 1/5 the average spacing of the input data. Another important aspect of the cell size which must be taken into consideration, particularly on large datasets, is that halving its size will have the effect of double the file storage requirements of the output grid. For example if you set a cell size of 2m and the output grid requires 1Gb of disk space, then reducing the cell size to 1m will increase the storage space requirements for the output grid to 4Gb.

Compute cell size

The compute cell size button will compute a default cell size for the input data. It attempts to do this by analysing the spatial statistics of a small subset (approximately 65,000 stations) of the first input file. Depending on the regularity and spatial coherence of this small subset of data the estimated cell size may or may not be assigned an optimal value.

If you are unfamiliar with the dataset and you are not sure what value to set for the cell size then it is recommended that you leave the property set to "Auto". When configured this way the software will dynamically adjust the cell size to an appropriate value after it has examined the complete spatial statistics of the input data.


Define grid geometry

The define grid geometry properties control the spatial extent and size of the output grid file. By default these values will be automatically computed by the software to fully encompass the input data once it has scanned all the data files and established the spatial statistics and data distribution. If you need to constrain the output grid to a larger or smaller area than the extents of the input dataset then you can override the default settings and specify the extents manually. By configuring the grid extents to an area which is smaller than the extents of the input dataset you will effectively clip it to the defined grid geometry. If the output grid geometry is smaller than the input data then any input data that does not overlap with it will be discarded prior to gridding. The grid geometry is controlled by the Origin X and Origin Y coordinate values, which specify the centre coordinate of the lower left grid cell and the number of rows and columns measured in grid cells.

Advanced settings

The advanced settings allow you to control a number of properties relating to the memory and temporary storage space requirements used during gridding, the resolution at which the initial data scan is done, the triangulation parameters and output grid data type. Details of each of these properties are described below.

Options

Maximum memory use

This control is used to constrain the amount of physical memory (RAM) that the software will attempt to use during the gridding process. The default control setting is disabled and in this state the software will attempt to use up to 80% of available physical memory during gridding. While it is possible to constrain the amount of RAM that is available to the software during the gridding process by setting a maximum value; doing so may reduce the gridding performance significantly if the software has to repeatedly page tiles of data between disk and memory in order to triangulate it.

To achieve best performance on large datasets it is advisable that you close all running applications and free up as much physical memory (RAM) as possible before commencing gridding. For very large datasets (>50 Million points) it is recommended that the software is run on a machine with between 2 and 4 GB of RAM.

Note The tool is only a 32-bit program, and therefor cannot address more than 4GB of RAM on a 64-bit OS.


Scan data extents

Controls the resolution at which the software initially scans the input data files to establish the spatial statistics during the first phase of gridding. The default behaviour is to scan all lines of the input data. It is possible to speed up the initial scan of the input files by adjusting the scan data extents control to one of the following settings:

• Complete: scans every line of each input data files

• Fine: scans approximately 12% (1 in 8) of the lines from each input data file

• Course: scans approximately 3% (1 in 32) of the lines from each input data file

• Overview: scans approximately 0.75% (1 in 128) of the lines from each input data file

• Bounds: acquires the data extents from information stored in the files (e.g. LAS) if available or performs an Overview scan if unavailable.

Temp directory

The temp directory is used to temporarily store the spatially sorted input data tiles which are used during the gridding process. If all of the input data can fit into system memory then no temporary files will be created and the entire process will occur in RAM. If the input dataset is very large (>50 million points) then it will be necessary to store a copy of the input data on disk during the gridding process. By default the temporary directory is set to the Windows system temporary directory; however it may be necessary to map it to an alternative storage location depending on the size of the input dataset.

Note: you should always ensure that you have at least the same amount of free temporary storage space as the total size of the input dataset.

Triangulation Parameters

The triangulation parameters can be used to influence the geometry of the output grid and the number of points and therefore memory that will be required to triangulate each tile of input points.


Distance specified in data units

Used to control the units of distance that the Maximum triangle side length property is measured in. By default this control is disabled and the maximum distance unit is expressed as a ratio of the tile (or patch) size. If you wish to constrain the Maximum triangle side length to a fixed value that is measured in data units (e.g. 100m) then enable this control and enter in the appropriate value. If the entered value is large and exceeds the size of an individual tile of data then it may have no effect.

Maximum triangle side length

This parameter applies to the triangulation phase of gridding and can be used to minimize or eliminate long thin triangles that may be created across large holes in the data or between widely separated points that lie around the perimeter of the dataset. By default triangles that are created with a length that is greater than half the diagonal length of a tile will be discarded. The size of the tiles used during triangulation are determined by the software, however you can modify them by applying a Triangle patch multiplier.

Triangle patch multiplier

The triangle patch multiplier can be used to modify the number and size of tiles (or patches) that the software will segment the input data into before sequentially triangulating it. The tile size is automatically determined by the system following a detailed analysis of the spatial statistics of the input data; however it can be modified by applying a Triangle patch multiplier. Increasing the default value of 1 to a higher number will fill in holes in the dataset but it will also increase peak memory usage during gridding. For very large datasets increasing the Triangle patch multiplier will reduce the number (but not size) of temporary files that are created during the gridding phase.

Output Grid

Data type

The data type control is used to set the numeric storage type for the interpolated values in the output grid. It is advisable to select the appropriate data type that most efficiently represents the range of data that will be stored in the output grid. For example a signed 2 byte integer is generally suitable for storing typical elevation data at 1m vertical resolution. The table below lists the available options and the valid data range that can be stored by by each of the data types.


The automatic option will set the output format to an appropriate data type based on an analysis of the input data range.

Grid format

The output grid file(s) can be specified as either a single band ERMapper or BIL format grid. Although both of these formats support multiple bands in a single file, the grids created by the Large Multi-file triangulation tool can be extremely large, so we have chosen to output each band (or field) to a separate grid file for convenience. If multiple fields are selected for interpolation then multiple output grid files will be created. The name of each file will be the user specified name (e.g. Sylvania) with the field name appended to it in square brackets (e.g. Sylvania_[elevation].ers).

In addition to the ER Mapper (.ers) or BIL (.bil) grid header and data files a MapInfo .TAB file will also be generated for each output grid.

Grid projection

A projection must be assigned to the output grid(s). While it is possible to specify different projections for the input data and output grid it is not recommended for very large datasets as it may degrade the performance of the input processing phase significantly as each point will need to be reprojected into the output grid coordinate system prior to gridding.

Auto open output file(s)

When enabled the output grid file(s) will be automatically open into MapInfo.

Data Type Bytes Range of ValuesUnsigned byte 1 0 to 255Signed byte 1 -128 to 127Unsigned short 2 0 to 65,535Signed short 2 -32,768 to 32,767Unsigned int 4 0 to 4,294,967,295Signed int 4 -2,147,483,648 to 2,147,483,647 Float 4 -3.8e-38 to 3.4e38


Converting Vector Surfaces to Grids

Surfaces>Convert Vector File to Grid

The Convert Vector File to Grid utility is designed to convert 3D vector surfaces (i.e. continuously triangulated surfaces) into 2D surface grids, with the Z values assigned as grid cell values. Suitable vector files for this include semi-planar 3D surfaces such as fault planes or an open cut mine model.

An interpolated DXF fault plane surface in the left image converted into an ERMapper grid in the right image. Images from Encom’s Discover 3D application.

The following input vector and output grid file formats are supported by this utility:

Vector Files:

• 3D Studio Files (.3DS)

• AutoCAD DXF Files (.DXF)

• Datamine Wireframe Files (.DM)

• ER Mapper Vector files (.ERV)

• ESRI TIN Files (.ADF)

• Gemcom BT2 Files (.BT2)

• GOCAD Vector Files (.TS, .PL and .VS)

• Surpac DTM Files (.DTM)

• Vulcan Triangulation Files (.00T)


Grid Files:

• ERMapper Grid Files (.ERS)

• Geosoft Grid Files (.GRD)

• Vertical Mapper Grid Files (.GRD)

• Surfer Binary Grid Files (.GRD)

• GeoTIFF Files (.TIF)

• Arc ASCII Grid Files (.ASC)

The Vector File to Grid dialog

Click on the Browse button to display the Open dialog to load a vector file from its known file location. Once the vector file is loaded the Data range section of the dialog is populated with the minimum and maximum Easting (X), Northing (Y) and Elevation of other “Property” (Z) values.


Under the Output grid properties section the Cell size is filled with a default (safe) value based on the vector file dimensions. Edit this value to the desired cell size. The Rows and Columns boxes are updated to compute the edited cell size.

By default the option to Use null values where there’s no data is enabled. This will populate any grid cells that do not have a Z value with the null value. Minimum or maximum Z value options are also available. For example, in the above file any empty cells could be populated with the minimum value of 87.71 or a maximum Z value of 579.41.

When satisfied with the output grid cell size select the Create grid button and save the grid name and location using the Save As dialog that appears. Click on Save to complete the file conversion.

Interrogating a Grid

• Interactive Query

• Summary Statistics

• Statistics by Polygonal Region

Interactive Query

Note To produce an alternate grid view (other than ‘top down’ or plan view), use the Discover>Import and Export>Transform Vector File tool to first rotate and swap the axes of your model. Once the axes have been rotated/swapped, running the Vector File to Grid tool will provide a different aspect view of the model.

Note The Vector File to Grid utility will not automatically open the generated grid into a map window display in MapInfo. To view the grid file it must be re-imported using the Surfaces Import Grid utility.

To report grid cell values directly to the screen, click the Grid Info button on the Surfaces toolbar. When the Grid Info tool is selected, place the cursor over the surface grid and click with the left mouse button. The cell values for the grid cell at the selected location plus the surrounding eight grid cell values are displayed in the Grid Info dialog box.


Summary Statistics

Surfaces>Grid Information

The Grid Information menu option enables a user to view a summary of grid information and statistical parameters. Select the grid using the browse button in the Grid Information dialog and Discover will populate the fields with the corresponding grid parameters.

Note This is similar to the MapInfo Info tool, but provides higher accuracy as well as the surrounding grid cells location.

Note For large grid files, the Grid cells sampled for statistics calculations may be less than 100% and therefore an approximation. This reflects the default sampling settings in Surfaces>Grid Handler Preferences. To increase the accuracy of the statistics sampling for a grid, use Surfaces>Precompute Grid Statistics to recalculate the statistics at a higher sampling.

Note The Grid Coords reflects the embedded grid file projection if known. If this is different to the MapInfo Coords projection, the grid file is registered differently in MapInfo.


Grid Information dialog

Statistics by Polygonal Region

Surfaces>Grid Utilities>Statistics

Use Grid Utilities>Statistics (see Using the Grid Utility Tool) to report grid statistics within one or more polygonal regions.


Computing Grid Values by Expressions

Surfaces>Grid Calculator

The Discover Grid Calculator can apply arithmetic operations, logic, comparative and Boolean operations directly to grids or between grids in any supported grid format. It performs the operations directly writing to the disk file, and does not require the grid to be loaded into memory or opened in MapInfo Professional.

Grid Calculator dialog


Grids can be assigned an alias name to enable the shortening of complex file names for ease of use in the expression line. For example, the grid file Rockchip_samples_As_210503 can be simplified to the alias name X. This enables the following simple expression output=X/(X*2) to be entered into the expression line rather than full grid name. To create a grid name alias, double click on the relevant cell in the Alias Name column and type the desired alias name.

The Grid Calculator requires a formula to be specified in the Expression line in the middle of the dialog. Complex grid operations such a Boolean and decision functions can also be applied. These grid operations are described in detail in Reference Manual: Grid Calculator Syntax.

If the areas covered by selected grids are different, results are computed only for grids where data overlap occurs. The remaining area of the first grid specified in the expression line is filled with nulls. If node points are offset between grids, the data is interpolated prior to computation. If grids of different mesh sizes are used, the mesh size of the first specified grid in the expression line is output.

Available grids are displayed in the scrollable list at the top of the dialog. This list is initially populated by all grids currently open. Further grids can be added to the list using the Load Grid button, and removed from the list using the Delete Grid button. Use the Information button to obtain details of a selected grid.

Note In the Grid Open dialog a range of supported grid formats are available. The Grid Calculator can be used to convert grid formats if required. Grid to grid computation can also be performed irrespective of the input formats or requested output format.


Create Expression

The Grid Calculator expression line and button controls are shown below.

Grid Calculator button layout and command line control

An expression must be a ‘correct’ arithmetic formula of the format:

output = function(input)

A new grid file alias must be entered on the left hand side of the expression. By default this is "output". This alias is automatically used by default for the output grid file name when the output grid is generated.

Note In the above example, a new grid (named Regolith_Grid) is to be created from subtracting an existing grid from another (Spot_Heights - Basement).

To add a grid to the expression line, place the cursor at the desired location in the expression (if not already there), highlight the grid in the grid list and press the Add Grid button.


Click the individual operation buttons to enter the operation into the expression line. Formulas can be entered directly into the expression line by keyboard entry or by selecting the appropriate fields and buttons via the Grid Calculator.

The Insert Function button enables the construction of complex formulae. A wide range of arithmetic, logic and Boolean operations are available from within the Grid Calculator. When a function is selected from the Insert Function pulldown list a definition of the function and the syntax required is displayed in the Grid Calculator dialog.

The actual output grid file name can be to be specified when the expression is computed in the Output section or using the file Save As button. If the output file name is not changed, the alias name is automatically saved. The Output grid file type can also be selected from the Format drop down list. The Compute Summary statistics option enables the calculations of grid statistics which are used by Discover's Grid Handlers to display the grid in MapInfo Professional.

When the expression is completed, press the Compute button. If the syntax is correct, a progress window is displayed as the Grid Calculator processes the expression. If there is a syntax error in the expression line the following dialog is displayed:

Incorrect expression line syntax dialog

Once the calculation is finished the new grid will automatically be opened in a map window.

The Recently Used Expression button opens a drop down list of functions last used in the Grid Calculator.

The Save As button enables an expression to be saved to a text file. Use the Load button to re-load the saved expression into the Grid Calculator dialog.

Note To use the Grid Calculator for a simple grid format conversion, use an expression in the form Newgrid=Oldgrid, and specify the new file format in the output section. An easier alternative is to use the Surfaces>Grid Utilities>Convert tool.


Grid Colour and Shading

Surfaces>Modify Grid Display

Grid display colouring options

Use the Select Grid pull-down list to choose the surface grid to modify.

Discover ships with a colour look-up table (LUT) library. Use the Select Colour Table pull-down list to choose another look-up table from this list to modify the current grid display. To view the colours used in the LUT the colour look up table is displayed in the preview pane on the right of the Modify Grid Display dialog.

Alternatively, use the Browse button to open an ERMapper (.LUT), MapInfo (.CLR) or Geosoft (.TBL) colour look-up table from another source.

Use the Modify Grid Display menu item or button tool to enhance a grid display. Change the appearance of a grid by the selection of a new colour look-up table (LUT) from a list of pre-defined colour table. Re-calculate LUT table colour limits based on data ranges and create new colour look-up tables using the LUT Editor. Apply sun-shading to a grid fom a specified direction and elevation angle or make a grid transparent.


See the LUT Editor section for more information on creating and modifying colour look-up tables.

Methods

A number of surface grid colouring methods are available:

• Full Linear StretchApply a linear colour look-up table to the grid between the minimum and maximum values. By default the minimum and maximum data ranges are selected but these values can be manually changed under Options. To return to the original data limits click the Reset to Input Limits button.

• Autoclip Linear StretchApply a linear colour look-up table between the middle n% of the data. Choose from a 99.9% or 99% clip to remove high and low data values and prevent distortion of the grid display.

The Low Clip and High Clip data values are displayed for each clip option and can be turned off by checking the appropriate box. Alternatively, manually enter clip values. The corresponding data value is displayed next to the clip value. Data values below the minimum and above the maximum are displayed with those minimum/maximum colours.

• Histogram Equalization Discover analyses the distribution of data in the grid and applies colours so that there are approximately equal numbers of grid cells displayed in each colour. By default the minimum and maximum data ranges are selected but these values can be manually changed under Options. To return to the original data limits click the Reset to Input Limits button.

Check the Recompute Histogram box to distribute the colour table evenly over the data range if the input limits are changed.

• Colour to Percentile BreaksWith geochemical data, it is often appropriate to show the grid coloured into just a few ranges, based on the data distribution. For example, gridded geochemical data may be coloured with ranges of 0, 30, 60, 80, 90, 95, 98 and 100%. Each of these ranges would be shown in a different colour to highlight the areas of interest.

Note For Autoclip Linear Stretch the colouring is applied using Percentile Clips, however within the dialog the corresponding data value is presented as a Percentage Clip, which is an approximation of the percentile value.


Enter a percentile and left-mouse click in the Colour box to display the colour palette. Select a colour and repeat process for each percentile.

• Colour to Data BreaksSimilar to percentile ranges, colouring by data ranges allows the grid to be displayed with a discrete number of colours, specified by data value rather than percentile value.

Enter a data value and left-mouse click in the Colour box to display the colour palette. Select a colour and repeat process for each percentile.

Selecting ranges for colour to percentile breaks and colour to data breaks

• Copy Grid Display ParametersUse the grid display from another grid to colour the current grid. Select the grid from the list of currently open grids or use the Browse button to open a new grid.

Transparency

Use the Transparency slider to set a transparency level for the grid. Transparencies can be set between 0% (no transparency) through to 100% (completely transparent).

Transparency Selector


LUT Editor

Colour look-up tables can be created and modified using the LUT Editor. The look-up tables are stored in the .\Program Files\Encom\Common\LUT directory. If an alternate directory exists where the look-up tables reside, the Settings button opens a dialog which allows the user to browse to the specified directory.

The format of LUT files varies depending on the saved format type. Supported types include:

ER Mapper (.LUT)MapInfo Professional (.CLR)Geosoft Oasis (.TBL)

LUT Editor dialog

The LUT Editor dialog is divided into functional areas. On the left is a scrollable list showing all the available Look-up Tables. Beneath this list are New and Delete buttons for creating and removing look-up tables (LUT). In the centre of the dialog the selected LUT is displayed showing the various colour settings for each of the rows specified in the LUT with descriptive comments if required. At the top of the dialog is the selected LUT name, an LUT description and the actual filename. On the right of the dialog is a preview of the entire LUT as it would be applied to an image, profile or display. The buttons at the base of the dialog are used to control the distribution of colours in the LUT.


A LUT is comprised of a number of rows generally in the order of 16, 32, 64, 128, 256 etc. Each row can have a colour individually assigned, or a group of rows can be selected and the colours distributed through the row range.

Once a LUT has been specified it can be stored using the Save button (into the LUT directory), or into a different location and with a different format if required using the Save As button. The above LUT formats are provided as options when the Save As dialog is displayed.

Create Look-Up Table

To create a new LUT click the New button.

Create new lookup table dialog

Enter a Name and the Number of entries (rows or colours) to be assigned to the new LUT. Check the Specify the data value corresponding to each colour box to precisely match data values with a colour from the table. For example, if the data has a range of 51,000 to 51,500, the colour look-up table can contain 500 definable colours for each of the 500 data values. Note that if this utility is used, the created LUT cannot be used within ER Mapper.


Data specification with a range of colours

When a new table is created it is added to the Look-up Tables list and a blank colour table is displayed in the centre of the LUT Editor dialog. Select HSL or RGB from the Colour Interpretation pull-down list. Left-mouse click any of the Colour cells of a row to select a colour from the standard colour palette. Use the Custom option to create additional colours.

To create a colour spread over a range of cells colour and select two end member cells in non-adjacent rows by holding down the Shift or Ctrl key. Click the Interp Selection button to fill the intermediate blank cells with graduated colour. Use the Clear Cells button to remove colour from highlighted cells. To view the Red, Green, Blue values for each row check the Show RGB values box.


Selected cells can be all set to match the FIRST selected cell using the Duplicate button. This always operates from the top-most selected cell down, irrespective of the order in which the cells were selected. Extra rows can be added or deleted using the Insert or Delete Rows buttons.

If the Specify the data value corresponding to each colour box was checked when the LUT was created enter the minimum and maximum data values next to the corresponding rows in the Data column. Click the Interp Gaps button to populate each intermediate row with the corresponding data value.

Any nominated LUT files in the displayed list can be deleted using the Delete button on the bottom left of the dialog.

Sun-Shading

Sun-Shading tab

Discover provides the option of adding real-time sun-shading to a gridded surface to improve the appearance of relief in 2D. Sun-shading works by brightening areas of the grid that face the direction of the sun and darkening those areas that face away from the sun, or are “in shadow”.


Sun Shade

Check the Sun Shade box and enter a sun Angle between 0 and 360°. Enter a sun Elevation between 0 and 90°. The position of the sun is displayed in the preview window. Alternatively, click on the sun icon in the preview window and drag to the desired sun angle and elevation.

The Saturation, Intensity and Shadow levels can also be modified.

Sun Highlight

Check the Sun Highlight box and enter a highlight Angle between 0 and 360°. Enter a highlight Elevation between 0 and 90°. The position of the highlight is displayed in the preview window. Alternatively, click on the light icon in the preview window and drag to the desired sun highlight angle and elevation.

To view sun shading and highlight modifications automatically in the grid check the Auto Apply box. Otherwise enter the sun details and click the Apply button when complete to change the grid display.

Histogram

The Histogram tab provides an interactive easy-to-use interface to visualize the data ranges and colour scheme applied to the selected grid.


Histogram tab dialog

The grid Histogram visually represents the distribution and data populations contained in the grid dataset. The grid Histogram enables the user to instantly view the effects of changes to the grid using the various colour methods available. The input data can be clipped to display colour between pre-set ranges or according to percentile and data breaks created in the histogram window. See the Colour tab for more information on the grid colour Methods available.

To view the exact number of grid cells and data value on the histogram, place the mouse cursor within the histogram frame to review values via a screen tip text box. The Histogram dialog is composed of a movable trend line used to adjust either the data range or clip colour values. To move the trend line, a drag handle is docked on both ends of the line. Place your mouse cursor over the handle, hold down the left mouse button and drag the handle to the desired location. Once you have moved the trend line into the correct position click the Recompute Histogram button to refresh the histogram display.

Note The Histogram and Colour tabs are directly linked so when values are changed on one tab they are directly reflected on the other tab.


When the colour input values are modified by moving the trend line handles it is possible to zoom into the new data extents by clicking the Zoom to Clip button.

Zoomed to the modified data extents

Alternatively, if you wish to zoom back out to the extents of the data limits for the Histogram press the Zoom to Data button.

Percentile and Data Break Stretch Types

The Histogram graphically displays the position of data and percentile breaks relative to the histogram data populations. To create a break, double-click at the desired value position. To adjust the positions of the percentile or data breaks, place the mouse cursor over the break line until the cursor appears as a double arrow and then drag the break line to a new position by dragging with the left mouse button.

Note Although data values can be altered using the trend line, manual inputs can be specified using the text boxes located beneath the Histogram.


Histogram tab showing data breaks

As data breaks are added, the colour distribution will be altered automatically.To manually adjust the colour scheme, right click between the data breaks to expand a selectable colour palette.

Histogram tab Colour Palette

To delete a break line from the histogram select the break line you wish to delete and drag the line off the edge of the histogram frame.


Display a Colour Legend

Surfaces>Make Legend for Grid

Grid Legend map window

Filtering Grids

Surfaces>Grid Filter

The Grid Filter is a powerful tool that provides the following functionality:

• Apply Convolution grid filters including smoothing, edge enhancement, sun-angle and user-defined filters

Display a legend relating the grid colours to data values. A legend appropriate to the display style is generated and may be added to a layout window for printing. The legend is created as a table in the same directory as the original grid. The grid legend annotations are displayed in a separate Labels table.

Note If the grid display has been modified using the MapInfo Map>Modify Thematic Map utility, the Discover legend will only display the original grid colour parameters. To create an updated grid legend, select the Make Legend for Grid menu option again.


• Apply Geophysical FFT filters

• Apply Padding to grid to remove edge effects

To access the GridFilter dialog, a grid must be open in a map window. Select the Surfaces>Grid Filter menu option to open the GridFilter dialog:

The GridFilter dialog with input, raw and filtered grid previews

Additional grids can be loaded from within the dialog using the Browse button. Specify the grid format from the Files of Type entry in the Open dialog.


Use the Files of Type option to select a specific file type

Once loaded, the grid content is displayed in the three preview windows.

Preview Windows

The Full Input Grid window displays the entire original input grid. The Raw and Filtered windows may show either the entire grid or a portion of the input grid. The Filtered preview window displays the output grid with the selected filters applied.

To examine the effects of the filtering process more closely position the cursor in the Raw or Filtered preview window. When the cursor is placed in one of these preview windows initially it is displayed as a ‘magnifying glass’. Click the left-mouse button to zoom the view inside the Raw and Filtered preview windows. To return to the previous zoom view, click the left-mouse button again. To pan a zoomed view, click the right-mouse button and when the cursor ‘hand’ is shown, drag the zoomed image to display a new view.


Zoom Cursor Pan Cursor

If the input grid is larger than 400 x 400 rows and columns, a small rectangle is drawn over the original grid in the Full Input Grid window. This rectangle indicates the portion of the grid that is being processed in the other preview windows. The rectangle can be selected by the cursor and moved to a new part of the input grid if required.

Grid Filter Information

Grid Information for three preview windows with zoom and filter applied

Grid information relating to the size, rows/columns and data within each of the three preview windows is using the Information button. If a preview window is zoomed or has one or more filters applied the three grids will contain different grid data content as indicated in the Grid Information dialog:


Applying Grid Filters

The Convolution and Geophysical buttons provide pull-down lists of available filters. Selected filters are listed in the window beneath these buttons. A full list and description of the available grid filters is provided in Reference Manual: Grid Filter Descriptions. The GridFilter dialog automatically updates to display the effect of the selected filters. More than one filter can be applied with a cumulative result.

As each filter is selected, it is automatically applied to the portion of the grid displayed in the Filtered window. The area over which the filters are applied is indicated by a square drawn in the Full Input Grid. The raw content of this area is displayed in the Raw preview window. The combined output of the processing steps is shown in the Filtered window.

The GridFilter dialog automatically updates to display the effect of the selected filters. More than one filter can be applied with a cumulative result. The Filter Properties area details any controls that apply to a highlighted filter. These controls may include kernels, required wavelengths and filter specifications.

Check the Pad Grid before filtering box to extend the size of the filtered grid past the original grid boundaries so the interpolation can remove grid edge effects. Some grids may require Padding as a pre-processing stage necessary for application of certain filters such as Geophysical filters. See Grid Filter Settings for additional information on padding options.

Filling Gaps

The Fill Holes utility is used to replace nulls in a grid by interpolating the surrounding data values. Two Fill Holes options are available:

• Fill internal holes only Only internal holes or null grid cells which are not connected by nulls to the outer edge of the grid are given a new interpolated value.

• Fill internal holes and nulls surrounding grid All null grid cells in the grid are replaced with interpolated values.

Filters are applied in the order listed. The processing is applied such that the output of one operation is the input of the next. This means that complex processing can be applied cumulatively. To alter the order of operation, use the Up and Down button to the right of the operation list. To remove a selected filter, highlight it in the filter list and click the Delete button.


The method used to fill holes involves progressive interpolation from the outer rim of the hole towards the centre until the entire hole is filled. This process can be slow for large holes.

Saving the Filtered Grid

Once the desired combination of filters has been selected and an acceptable output presented in the Filtered preview screen, press the Save As button to create an output grid file. By default this will add a suffix to the input grid file name denoting the filters applied and save it in the source file directory.

The following formats are available to create output grids with:

ER MapperGeosoftVertical MapperSurferGeoTIFFArc ASCII

To automatically display the filtered grid in a new MapInfo map window after saving to the nominated output file, check the Auto open when saved box.


If the saved file format is ERMapper, Vertical Mapper or GeoTIFF a dialog may be displayed with a prompt to choose a projection for the output grid. The projection selected is embedded into the output grid file so the grid can be imported directly into third party software packages that support these grid file formats.

The projection selected must be the same as the original source grid and cannot be used to transform between coordinate systems. Use the Surfaces>Grid Utilities>Reproject utility to transform a grid into another coordinate system.

If an ERMapper grid is selected as the output grid type, a prompt will be displayed to select the Datum, Projection Type and Projection Member from a dropdown list. For example, if the gridded point data was located in the projection MGA94 (GDA94) Zone 54 the following parameters will need to be entered:

Datum: GDA94Projection Type: tranmercProjection Member: MGA54

If the gridded point data was located in either in a non-earth, affine or custom MapInfo projection, it is most likely that the coordinate system parameters will not be listed in the dropdown lists.

In this instance accept the default parameters and press OK. No projection information will be recorded in the grid file.

Note File names greater than 30 characters in length can be ambiguous when used with certain tools in MapInfo (such as the Layer Control). Discover displays a warning of this limitation if the specified output file name exceeds this limit.


ERMapper coordinate system dialog

Grid Filter Settings

Click the Settings button to access preview display and padding options:

The Show preview headings option toggles the text display in the preview screens on or off.

Note If a projection is not selected, the output grid will still open correctly in MapInfo. Failure to select a projection will mean that projection details will need to entered manually when the output grid is imported into a third party software program.


The Zoom level can be specified as default integer value: an entry of 5 will zoom the area to 5 rows/columns for each one seen in the original, upper preview window.

The Padding options permit an area surrounding the input grid to be created in order to minimise edge and filtering effects when certain filters are applied, primarily Geophysical filters. This Padding margin can be set as a percentage of the original grid area. Two methods are provided for the creating the padding margin. These are:

• Padding by row and then by column – This option duplicates the outer rows then columns of the input data grid and extends them outwards to the Padding margin to surround the grid

• Padding in 2D using gridding – This method extends the grid margin by extending the grid data and gridding it over the extent of the Padding margin. This method produces a relatively seamless edge to the grid and allows for smooth filter application without edge effects. This method is superior in many cases to the first because it eliminates the horizontal and vertical streaks which padding by row and then by column can introduce.

The Padding Margin is appended to the original grid and can be saved for examination if required by checking the Save padded grid box.

Contouring a Grid

• Creating Contours

• Labelling Contours

• Positioning Contour Labels

Creating Contours

Surfaces>Contour a Grid

Discover can generate contours for any registered Discover grid format, including those grid files generated by Discover.

Note It is recommended that padding is always used when applying a Geophysical FFT filter. FFT filters can only be applied to square grids so padding can be used to square up a grid.


Specifying the Contour parameters

Select the Grid to contour from the pull-down list. The grid must already be open in MapInfo. Contours are created as polyline objects.

Contour intervals can be specified in one of two ways.

1. Regular Contour Intervals - Discover suggests contour intervals based on the range of values in the first Z value column. The Major Contour Interval must be divisible by the (minor) Contour Interval. Specify different line styles for optimal visual effect by clicking on the Line Style button next to each contour interval.

By default, Discover will contour between the minimum and maximum table values. Alternatively, check the Specify maximum and minimum values to contour between box and enter the values manually. This can be extremely useful when contouring data with outliers (extremely high or low values), as it prevents Discover from spending extra time generating unwanted contour lines.

2. Contour Levels from text file – Discover can read a text file containing a simple text list of contour levels. Click on the Input Contour Level File button and select the text file. The text file should contain only the list of contour levels in increasing order, with a normal separator (comma, space etc.) between each level. An example contour level file is as follows:


5, 10, 15, 20, 30, 40, 60, 80, 100, 150, 200, 250, 500

A contour level file is very useful when the sample data is a non-normal distribution. Contours can be created to show more detail in one part of the data range than others. For example, a soil grid with gold values in the range of 0.01 to 25 ppb could have closely spaced contours in the range 10-25ppb, but be contoured using more widely spaced values below 10 ppb.

When a contour level file is used, Discover displays every contour line in the same line style. To modify the style of selected contours, use the MapInfo line style picker. To select the contour lines to modify, use a clause similar to the following in the select statement. This syntax will select contour lines which have a value as a multiple of 50.

where Pb_ppm MOD 50 = 0(replace Pb_ppm with your contour column name).

If the Contour Smoothing option is checked, each contour line is smoothed using a spline interpolation. This greatly improves the appearance of the contours though the size of the contour table is increased as each line contains more nodes.

If the Contour Colouring option is checked, each contour line will be coloured corresponding to the grid’s colour file.

Click on the Output Contour Table button and browse to the directory to save the new contour table. Enter a name for the new contour table. Discover creates contours as attributed polylines in a permanent MapInfo table. If contouring a read-only grid (such as on a CD-ROM) the contour lines must be saved to a folder with write permission.

Labelling Contours

Surfaces>Label Contour Lines

Discover can add Z value labels at user-specified intervals to contour lines. The labels are created as MapInfo text objects in a chosen layer, such as the cosmetic layer. Discover adds labels to any attributed contour plan that has a column for contour level value.

Note In certain instances (e.g. where many contour lines describe a saddle feature), turning contour smoothing on can result in some cross-over between adjacent contour lines.


This option can also be used to add line-parallel labels to other linework such as rivers or roads.

Specifying contour labelling parameters

The contour labels are placed parallel to the contour lines as normal text objects. If the contour plan and labels are then viewed at a different scale to that specified in this dialog, the Z value labels appear at a proportionately different size.

The distance between labels along each contour line is controlled via the Place Annotation every option. The number of labels on any individual polyline can also be capped to a maximum number.


Positioning Contour Labels

Surfaces>Contour Label Positioner

Contour labels can be custom positioned using a discrete number of intersecting polylines (generally perpendicular to the contour lines). Contour labels are placed at the intersection of these label path lines and the contour lines.

The Contour Label Positioner dialog, configured to only create labels for the 5m and 10m contour levels.


Using the Contour Label Positioner. The left hand image displays the source contour lines (coloured) and 3 intersecting label path lines (blue), the intersection of which will control label placement. The right hand image shows the resulting labels. Note that only specified contours were labelled, using the Minor and Major Label Intervals (illustrated in the dialog image)

This tool requires two tables to be specified: the Contour Lines table (created using the Surfaces>Contour Grid option) and a Label Path Lines table. The Label Path Lines table must be a separate table to the contour lines table and contain one or more lines or polylines that intersect the contours. Label path lines drawn in the Cosmetic Layer cannot be used (use Map>Save Cosmetic Objects to save them to a new table).

• Label path lines should generally be drawn at a high angle to the contour lines; this will create labels that are approximately parallel to the contour lines.

• The output labels will be orientated perpendicular to the label path line: a vertical line will result in horizontal labels). The label path line start point is used as the label ‘up’ direction. Drawing label path lines from left to right, and from top to bottom of the mapper window, will therefore generally result in logically orientated labels (i.e. upright). Note that line directions can be reversed using the Discover>Object Editing>Change Line Direction tool.


• To orientate all labels horizontally (i.e. ignore label path line directions), select all labels, and select the Discover>Map Making>Format Text menu option. Tick Alter text labels, and set the New Angle to 0. All labels will be rotated so that they are horizontal.

• A small number of label path lines can be quite effective, particularly when placed along major features such as ridge lines and gullies.

The Contour Label Positioner will label all intersecting contour lines by default. This option can be disabled, allowing only specific contour levels to be labelled (the examples pictured label only the 5m and 10m contours). These labels can be saved to a new or existing table. If a new table is created, it will include a Cont_Label field attributed with the appropriate contour value.

Creating Polygonal Regions by Selection Criteria

A range of tools are provided on the Discover>Surfaces>Grid Query menu for creating polygons that bound regions of a grid based on selection criteria:

• Select Cells by Value Range

• Select Cells by Multiple Value Ranges

• Select Cells by Surface Property

Note As with all Discover labelling tools, it is recommended to first create labels in the cosmetic layer in order to refine their size (using the font size and scale controls). These can be easily cleared using Map>Clear Cosmetic Layer. Once a satisfactory label size has found, either specify a new table to create the labels into (from within the tool), or save the cosmetic layer to a new table. Note however that labels saved to the cosmetic layer do not store the contour value as an attribute.


Select Cells by Value Range

Surfaces>Grid Query>Select by Value

The grid query tools provide a convenient method of creating MapInfo polygons that cover the areas of the grid that meet the grid query criteria.

The Select by Value query tool can be used to select all grid cells greater or less than a nominated value or between two selected values. Grid cells that match the selected criteria are combined into a single polygon with non-contiguous grid cells combined into a multi-polygon (a polygon that is made up of individual polygon components but contains only one browser record).

Grid Query dialog

The fill and line style for the created polygons can be selected using the Regions Style buttons. Select an appropriate name and location for the grid query polygon table. If no name is selected the grids will be named consecutively GridQuery1, GridQuery2, etc and stored in the default directory location.

Note Multi-polygons may be split into their individual components using the Object Editing>Split Multi-Polys tool.


Select Cells by Multiple Value Ranges

Surfaces>Grid Query>Select by Multiple Ranges

Create coloured vector polygons from selected areas in a grid based on grid cell data ranges or percentiles.

The Select by Multiple Value Ranges query tool can be used to select all grid cells which fall within entered percentile or data ranges. Grid cells that match the selected criteria are combined into a single polygon with non-contiguous grid cells combined into a multi-polygon (a polygon that is made up of individual polygon components but contains only one browser record).

The created vector polygons may represent percentile ranges from a geochemical grid or areas from a DTM grid which correspond to selected elevation intervals.

Open the Select by Multiple Value Ranges dialog and select the input grid from the Select Grid pull-down list.

Select by Multiple Value Ranges dialog

Vector polygons may be created from the following multi-value range methods:


• Percentile Create and colour vector polygons from grid cells values according to the percentile range that each grid cell value falls within. A percentile is a value on a scale of 100 that represents the percent of a distribution that is equal to or less than the entered value. For example, gridded geochemical data may be extracted to regions using percentile ranges of 30, 60, 80, 90, 95, 98 and 100%. Each of these percentile ranges would be shown in a different colour to highlight the areas of interest.

Enter a percentile into the Levels window and left-mouse click in the Colour box to display the colour palette. Select a colour and repeat process for each percentile.

• ValueCreate and colour vector polygons from grid cells values according to the data range that each grid cell value falls within. The data values entered will be used to create polygons from grid cells whose values are equal to or less than the entered value.

Enter a data value and left-mouse click in the Colour box to display the colour palette. Select a colour and repeat process for each data range.

Output Options

By default the output vector polygon table is named using the original input grid name with a “_query” extension and saved to the same folder. To modify the new table name or location click on the Save button.

Original input grid Percentiles vector polygon layer


Select Cells by Surface Property

Surfaces>Grid Query>Select by Elevation, Slope, Aspect

The Elevation, Slope, Aspect query tool has relevance only for digital elevation model surface/topographic grids. It provides the functionality to perform a complex query, such as would be required to identify steep slopes. Other options enable regions of certain elevation or slope to be isolated.

The Aspect parameters refer to the facing direction of the slope; for example, selecting by Octant ‘N’ will select northerly facing slopes.

Querying a grid to return polygon covering the required areas

Note The Grid Utilities>Slope tool can convert the entire grid to the corresponding grid cell slope values.


Creating Grid Profiles

Surfaces>Draw Grid Profile

Profiles over multiple surfaces may be displayed together to show, for example, topographic relief together with magnetics and soil geochemistry, allowing relationships between the surfaces to be examined. Additionally, vector data such as surface geology polygons and fault lines can be draped over the profiles, further enhancing the analysis.

A single selected polyline profiling 3 individually coloured grids (a DEM and two geochemical surfaces). Note that the current cursor location in the profile preview is marked on all three profiles, as well as being indicated spatially by a red star in the mapper window. The geochemical grids have both been Scaled and Offset using the controls discussed in step 8 below.

The Draw Grid Profile function provides a powerful tool for identifying and analysing trends or spatial relationships between gridded surfaces. Profiles for one or more lines or polylines can be generated across multiple gridded surfaces or contour plans.


To create a profile:

1. Open a number of coincident gridded surfaces (e.g. geophysics, geochemistry and DEM) into the same map window.

2. Make the cosmetic layer editable in this map window, and draw one or more lines/polylines across the grid regions of interest

3. Open the Profiler tool (select Surfaces>Draw Grid Profile)

4. Select a line in the cosmetic layer: the dialog will refresh, displaying the profile of the selected line across each underlying grid surface.

5. If multiple lines/polylines are available, use the SHIFT key to select multiple lines: the tool will refresh to include a profile for each selected line and each grid.

6. If multiple grids are open, their display in the Profiler can be controlled by pressing the Options button at the bottom right if the dialog. In the Profiler Options>Data tab, press the Select Grids to Profile button. The following controller allows the current mapper’s grids to be unselected/selected by moving them left and right.

7. To colour code the profiles (in order to differentiate for example between a profile of aeromagnetics versus gravity), select the Profiler Options>Legend tab. Use the browse button to the right of each grid to set a different colour for each grid.

8. Note that the Profiler Options>Legend tab also provides controls for Scaling and Offset of each individual grid. This is useful when trying to control the magnitude and positioning of geochemical/geophysical profiles with respect to a DEM/topographic profile.

9. Click in the Profiler preview area: a marker will be placed on each profile relating to this horizontal position in the preview. Simultaneously a symbol (default star) will be placed in the mapper window on the selected line/s indicating the associated location. This is a dynamically updated interface, allowing you to easily relate features on the previewed profile to spatial locations in the mapper window.

Note If the display does not automatically refresh, ensure that the Auto Update from Selected Line option is enabled under the Profiler Options>Data tab (accessed via the Options button).


10. To create a permanent profile, press the Export button in the main Profiler dialog. Select a TAB file name and location, and press Save. The profile as previewed in the dialog will be opened into a new MapInfo map window.

Data Selection

Profile lines

• One or more lines or polylines need to be selected

• These can be in a table, or the cosmetic layer

• They can be selected before opening the Profiler tool, or once it has been opened

• If multiple lines/polylines are selected, the profile preview will be drawn so all lines are drawn from the origin (left), regardless of their actual spatial positions.

• By default the profile preview is automatically updated when new lines are selected. This can be disabled via the Auto Update from Selected Line option in the Profiler Options>Data tab. To update the preview manually, press the Update Profile button

Gridded Surfaces

• Ensure that the required gridded surfaces (topographic, geochemical, geophysical, etc) are open in the mapper window (they do not have to be visible)

• To control grids from within the Profiler tool, select the Options button, and press the Select Grids to Profile button in the Profiler Options>Data tab. In the following dialog, ensure that the required grids are listed under the Selected list; move grids not required to the Unselected list.

Polygon and Polyline Intersections

Profiles can be coloured with coincident polygons, such as surface geology, regolith mapping, land use or vegetation maps, etc. Profiles will be coloured with the foreground colour of the overlying polygon.

1. Ensure that the polygon vector map is open in the map window (does not have to be visible)


2. In the Profiler Options>Data tab, enable the Show Layer Intersections option, and press the Select layers button.

3. Move the required polygon vector layer to the Selected list.

The intersection of profiles with coincident polyline data such as faults, drainage, tracks/roads, lineations, etc, can also be displayed:

1. Ensure that the polygon vector map is open in the map window (does not have to be visible)

2. In the Profiler Options>Data tab, enable the Show Layer Intersections option, and press the Select layers button

3. Move the required polyline vector layer/s to the Selected list.

4. Intersections will be marked on profiles as square symbols coloured using the intersecting polyline’s colour. Therefore using a table of blue drainage polylines, and another of red lineations, will display the relevant intersections as blue and red squares.

Multiple profiles over a DEM, coloured by a coincident polygon geology table, with drainage polyline intersections indicated by blue squares.


Interrogating Profiles

Interrogating multiple profiles using the Info tool

The Info tab of the Profiler Options dialog includes a Show Info Tool option. With this enabled, the cursor will report the profile's Distance, Value and X and Y coordinates at that point. This report can be either continuous (enable the Mouse Moves option in the Info tab), or only upon Button Clicks.

Simultaneously, the profile points location in the mapper window can be displayed if the Show position in MapInfo option is enabled.

To permanently mark a point’s location in the mapper window, right click on the location in the preview window, and choose Mark Point. A symbol will be placed in the mapper window using the style set under the Grid Options>Display tab>MapInfo mark symbol control.

Profiles can also be visualised in a tabular spreadsheet format, by selecting the spreadsheet button at the bottom left of the Profiler dialog. This view provides the following information for each point of a profile: Distance from the profile start, Value, and X/Y coordinates. Clicking in the profile preview area will highlight the corresponding point’s entry in the spreadsheet view.


Navigating the Preview window

Colouring and Controlling Profiles

The initial colour of profiles is controlled by the colour of the selected line/polyline, which can be a useful way of distinguishing between multiple profiles over a single gridded surface.

If creating profiles over multiple grids, each profile/grid combination can be coloured individually using the controls in the Profiler Options>Legend tab. Select the button to the right of the desired profile; the Base Colour can be changed in the following dialog.

The Scaling and Offset of each profile/grid combination can also be controlled from this dialog. This can be useful when trying to display multiple grids with large differences in the magnitude of their data ranges. For example, base metal soil sampling grids often have values in the tens of thousands: to display these over a topographic grid may require a scale factor of 0.1 or 0.05. An offset may then be applied to ensure that the profiles are presented in the same Y axis range.

Profiles can also be Smoothed in the Profiler Options>Legend tab. This filters the line by applying a weighted average algorithm across the line. Note that point values will not necessarily be honoured when smoothed.

The preview window profile can be zoomed in using either the mouse scroll wheel or by selecting the zoom buttons.

It can be panned by using by holding and dragging the right mouse click, or selecting the pan hand button.

You can reset the position of the preview window by clicking the reset button.

You can change back to the normal mouse pointer by selecting the button - this can display the mark within MapInfo and/or show the profile info at the selected point.


Customizing the Preview Appearance

The Display and Axis tabs of the Profiler Options dialog contain controls for the following:

• Axis display

• Axis bounds and tick spacing

• Grid line display

• Background colour

• Zero value line display

• Y axis value scaling (linear or log10)

• Y axis vertical exaggeration

• X axis scaling

• MapInfo position and mark symbol styles

Note that the X axis scaling is a data pre-processing step which simply multiplies the X axis values by the entered amount, e.g. a scaling of 2 will display twice the X axis range, and a scaling of 0.5 will display half the range and effectively double the Y/vertical axis.

Y axis exaggeration will scale, and then subtract the minimum value from the data. This will keep the minimum value at the same amount, and double the range of the data.

Output

The Profile Preview can be saved permanently as a MapInfo table, using the Export button. This table will reflect any customized colours, scaling, offsets, polygon and polyline intersections, etc displayed in the preview.

The spreadsheet can be exported either as a MapInfo browser or a .CSV file using the options at the bottom of the spreadsheet view.

Profiles can also be visualised and exported in a tabular spreadsheet format, by selecting the spreadsheet button at the bottom left of the Profiler dialog. This view provides the following information for each point of a profile: Distance from the profile start, Value, and X/Y coordinates. Clicking in the profile preview area will highlight the corresponding point’s entry in the spreadsheet view.


An output map window from the Draw Grid Profile tool

Creating Voronoi Polygons

Surfaces>Create Voronoi Polygons

The Create Voronoi Polygon function generates Voronoi polygons from a set of input points.

Voronoi Polygons are polygons that enclose one point with the border of each polygon. The polygon boundaries are located at the midpoint between neighbouring points. Voronoi Polygons are the “inverse” of a triangular irregular network and cover an area that may be thought of as the “area of influence” for that data point. The area within the Voronoi polygon boundary is closer in distance to the central Voronoi polygon data point than any other data point in the table.

Voronoi Polygons provide a method for creating a surface without interpolation and gridding. In many cases, for example when analysing coal or mineral sands drillholes, creating a surface of voronoi polygons based on the drillhole locations may be preferable to gridding.

When the Voronoi Polygons are created by Discover, all of the attributes of the points are transferred to the polygons, allowing for quick estimation of volumes or concentrations.


Example of Voronoi Polygons generated from sample locations

Discover generates Voronoi Polygons from selected points in the front map window. By default, the created Voronoi Polygons extend no further than the outer boundary of the group of selected points (the convex hull). However, the Voronoi Polygons may be extended by any distance outside of the convex hull by specifying the distance in metres or degrees.

A bounding polygon may also be used to contain the extent of the Voronoi Polygons. Select the bounding polygon before selecting the Voronoi Polygons menu item and all points that lie within the selected bounding polygon will be used to create Voronoi Polygons.

Create Voronoi Polygons dialog


When the polygons are created, they have the same table structure as the points table on which they were based. This enables the polygons to be easily coloured, queried or thematically mapped.

Calculating Surface Properties and Volumes

• Calculating the Volume Between Two Grids

• Calculating Volumes by Level

• Calculating Volumes Constrained by Polygons

• Calculating Slope and Aspect

• Calculating Curvature

• Calculating Cut-and-Fill Volumes

• Calculating Surface Areas

Calculating the Volume Between Two Grids

Surfaces>Grid Utilities>Volume

To calculate volumes between two grids, use Grid Utilities>Volume (see Using the Grid Utility Tool). The Grid Utility tool also provides options for calculating volumes above or below an elevation (by level) and reporting cut-and-fill volumes between two surfaces.

Calculating Volumes by Level


To calculate volumes between a grid and a horizontal plane, use Grid Utilities>Volume (see Using the Grid Utility Tool). The Grid Utility tool provides options for calculating volumes and reporting cut-and-fill volumes between two surfaces.

You can also calculate volumes by level with or without bounding polygons using the Calculate Volume for a Level tool (see Calculating Volumes Constrained by Polygons).


Calculating Volumes Constrained by Polygons

Surfaces>Grid Query>Calculate Volume for a Level

Use this function to calculate the volume contained between a gridded surface and a specified level. If no polygon objects are selected, then the volume of the whole grid to the specified level is reported as a single value to the screen. If one or more polygons overlying the grid have been selected then the volume for the portion of the grid under each polygon is reported to the screen or assigned as an attribute to each polygon.

The function can be used to calculate the volume of rock in a stockpile using a DEM of the stockpile or calculating the volume of water in a dam using a DEM of the bathymetry.

Calculate Grid Volume dialog for selected region

Calculating Slope and Aspect

Surfaces>Grid Query>Compute Slope or Aspect Grid

Discover provides a special grid calculation function to derive slope and aspect grids from digital elevation models. The slope and aspect values are calculated for each grid cell using elevation values in the surrounding cells.

Note The Grid Utilities>Cut/Fill or Grid Utilities>Volume tools provides additional volume calculations options.


Grid Arithmetic dialog

You can also use Grid Utilities>Slope (see Using the Grid Utility Tool) to calculate slope angle and direction.

Calculating Curvature

Reference Manual: Surfaces>Grid Utilities>Curvature

Use Grid Utilities>Curvature (see Using the Grid Utility Tool) to calculate the curvature of a grid.

Calculating Cut-and-Fill Volumes

Reference Manual: Surfaces>Grid Utilities>Cut Fill

Use Grid Utilities>Cut Fill (see Using the Grid Utility Tool) to calculate the volume added and removed between two grids.

Calculating Surface Areas

Reference Manual: Surfaces>Grid Utilities>Surface Area

Use Grid Utilities>Surface Area (see Using the Grid Utility Tool) to calculate the.non-planar area, planar area and roughness of a grid.


Manipulating Grids

Surfaces>Grid Utilities

Discover Grid Utilities provide numerous tools to simplify common grid manipulation, processing and calculation tasks. Most utilities support processing large multi-gigabyte grid files, with the exception of those marked in the list as memory limited.

The Discover Grid Utilities menu provides the following functionality:

• ClassifyClassify each grid cell into one of a number of ranges.

• Grid to Grid ClipClip a grid to the non-null area of another grid.

• ClipDefine a region using an irregular polygon or rectangle and remove the portion of the grid that lies within or outside this region.

• ConvertInput a data grid in one format and save to another grid format.

• Create RGB Combine separate grids having red:green:blue colour signatures to a single, multi-banded RGB grid file.

• CurvatureCompute curvature of a grid.

• Cut/FillCompute the differential volume of material added/removed between two grids.

• EditDisplay and edit a selected grid cell. View surrounding grid cell values.

• Fill HolesReplace nulls within or around a grid by extrapolating values using the surrounding data.

• FlipInvert the rows or the columns of a grid in their location either horizontally or vertically.


• Merge Merge several grids to form a new grid.

• OutlineCreates attributed polygons outlining the bounds of multiple grids.

• OverlayModify grid cell values based on polygon boundaries in a specified TAB or MIF vector file.

• Replace Allow specific grid values (such as Nulls or nominated values) to be replaced by another data value or Null

• ReprojectReproject a grid into a new coordinate system.

• ResampleGrids can be re-sampled to a new cell size using any of three available interpolation schemes.

• RotateA grid can be rotated about its defined origin by a specified angle. Interpolation processing is required for this procedure.

• ShiftApply an easting or northing offset to the origin location of a grid.

• SlopeAssigns cell values of either maximum slope angle or direction

• SplitUsed for multi-banded grids, this operation outputs separate component grids of the individual single bands.

• StatisticsCompute statistics for grid regions inside one or more overlying vector polygons.

• Surface AreaCompute the 3D surface area, planar area and roughness of a grid.

• VectorizeConvert a grid into polygons, using either individual cells, non-null regions, regions of discrete values or the grid bounds.


• ViewshedCompute the view-shed of one or more towers of a specified height above the grid to an observer at a specified height above the grid.

• VolumeCalculate the volume between two grids or the volume of a grid above or below a Z level.

Utilities can be selected from Surfaces>Grid Utilities menu, or directly from the Grid Utility tool, which is opened by selecting any utility on the Surfaces>Grid Utilities menu.

Using the Grid Utility Tool

Grid Utility dialog


The Utilities button displays a pull-down list of the available grid utility tools. Select a utility to display a description and the control parameters in the main potion of the Grid Utility dialog.

Depending on the grid utility selected, a range of parameters and options may be required to be entered, altered or selected. Full details of these are presented under the Utilities section below.

The Information button displays the registration and statistics for the selected full input grid, and the current preview tile before and after grids.

Grid Information dialog

The upper portion of the Grid Utility dialog displays all available open grids. Use the Browse button to add a grid to this list. If you wish to apply operations to a new flat grid, use the Create New Grid button.

Note Grid Utilities that operate on multiple grids (e.g. Volume, Grid to Grid Clip, Merge) require all source grids to be in the same projection. This can be easily accomplished using the Reproject utility.


Preview Window

The two grid windows on the right side of the Grid Utility dialog display Before and After views of the selected grid. As the grid selection or function is changed, the After preview window is redrawn and updated with the changes. Note that the visual changes occur in memory only and are not permanently saved until you specify and save an output grid using the Save As button.

A number of preview window navigation options are available:

The Column and Row position of the cursor in the preview window is displayed underneath the navigation tools.

At any time in the processing of a grid, the Stop button can be used to halt computation and return to the previous state.

To modify the appearance of a grid in the preview window click the Use Colour Look-Up table button to toggle between a grey-scale or colour grid display. To toggle between a linear or equal area histogram colour stretch use the Histogram Equalisation button.

Pointer mode – Change the cursor to this mode to select a position or cell value in a grid. The relevant coordinates and cell value will be displayed in the bottom left of the dialog.

Zoom In or Out – Select a zoom mode and left-mouse click the cursor in one of the preview panes. The zoom-in tool will halve the preview window zoom width while the zoom-out tool doubles the preview window width.

Pan the image by positioning the cursor in the preview window, holding down the left mouse button down and dragging to a new location. The re-drawn image is centred on the new location.

View the extent of the grid in either Before or After preview pane windows.

1:1 zoom ratio, such that 1 grid cell equals 1 pixel on screen.

Click Reload the preview tile, if the Before preview window has panned or zoomed outside the currently previewed bounds, and is not automatically reloaded.


Settings

Click the Settings button to display the Grid Utilities Settings dialog.

Check the Display crosshairs in the "After" preview for the selected cell box to display a ‘cross-hair’ cursor in the After preview window when using the Edit grid utility.

Cross hair cursor display enabled via ‘Show selected cell in preview’ Setting

Check the Show preview window labels box to display the “Full Input Grid", "Before” and “After” text in the preview windows.

Check the Use separate colour stretch for “After” preview box where the input and output data are scaled differently and it is necessary to apply a new colour stretch to the output grid.

Check the Update "After" preview when input grid is changed to automatically refresh the processed after preview window when the input grid is changed.

Check the Load default grid without prompting for grid selection to automatically load the first grid opened in MapInfo Pro into the Grid Utility dialog. Alternatively a dialog will be displayed whenever there is not a grid in the front Map Window, prompting a user to select which grid file to load initially, or to load no grid.


Check the Automatically load new tile when preview panned or zoomed to refresh the Before preview tile view from the full input grid, when it is panned or zoomed outside the bounds of the currently loaded preview area.

The Maximum size of grid for limited utilities is the limit on grid size, in million of cells, that you will be allowed to process on those tools with limited memory. It is recommend leaving this at the default 200 million, which is the upper limit of what can be processed on most typical modern computers.

Save Output Grid

Once a grid utility has been applied to a grid and an acceptable output presented in the After preview screen, click the Save As button to create an output grid file. By default the output grid is named using the original grid with an appropriate suffix based the grid utility applied and saved to the original file directory.

The default output file format for each utility is ER Mapper grid.

To automatically display a new grid in a map window after saving to the nominated output file, check the Auto open grid when saved box.

If the input grid file does not have an associated TAB file or an embedded projection with an EPSG code, a dialog will be displayed with a prompt to choose a projection for the output grid. This will be used to display the grid within MapInfo, and if it is a compatible file type, embedded in the grid file for automatic display in third party applications.

The projection selected must be the same as the original source grid, otherwise the grid will not display correctly. The only utility which allows the conversion of grid projections is the utility.

ERMapper Grid Output

If an ERMapper grid is selected as the output grid type for a Grid Utility, a prompt may be displayed to select the Datum, Projection Type and Projection Member from a dropdown list. This occurs so that the correct projection information will be added to the ERS header file, which utilises a different projection library to MapInfo, and cannot therefore be automatically populated.

For example, if the gridded point data was located in the projection MGA94 (GDA94) Zone 54 the following parameters will need to be entered:

Datum: GDA94Projection Type: tranmercProjection Member: MGA54


If the gridded point data was located in either in an affine or custom MapInfo projection, it is most likely that the coordinate system parameters will not be listed in the dropdown lists. In this instance accept the default parameters and press OK. No projection information will be recorded in the grid file.

If the input grid is in non-earth, the Datum should automatically be set to None: simply press OK to continue.

ERMapper coordinate system dialog

Classify

Surfaces>Grid Utilities>Classify

The Classify grid utility enables an input grid to have the value of each cell classified into one of a number of ranges. By default the input grid is automatically classified into 5 bins. Each bin represents an equal data range spread between the minimum and maximum grid values. The output cells are assigned a bin value of 1 to 5 based on the input cell value range.

Note If a projection is not selected, the output grid will still open correctly in MapInfo. Failure to select a projection will mean that projection details will need to be entered manually when the output grid is imported into a third party software program.


Use the Auto button to automatically classify the grid cells. Use the Auto classify dialog to modify the Input classification range and the Number of classifications or bins in the output grid. By default the bin or classification values start at 1 and increase by 1 but these options can be changed by setting a new Output value start and Output value step. The Output value start and the Output value step are saved in the registry and are used as the defaults next time the Classify utility is opened. The input classification range is re-computed each time a new input grid is loaded.

Complete manual control of the classification process is possible by manually editing the bin ranges. In addition use the Add row and Insert row buttons to append or insert a row and the Delete rows button to remove rows from the classification. Hold down the Shift or Ctrl keys to select multiple rows for deletion.

A bin value can also be set to be a Null value, by entering the text string ‘null’. This will assign the input grid null value to the specified bin range.


Grid to Grid Clip

Surfaces>Grid Utilities>Grid to Grid Clip

The Grid to Grid Clip tool allows a selected (Main) grid to be clipped to the extents of another (Secondary) grid. This requires both grids to be in the same projection (use the Reproject Grid utility to convert grid projections), and the grids must overlap.

To use:

1. Select the Main grid (i.e. the grid to be clipped) from the listing of available grids at the top of the Grid Utility.

2. Select the Secondary grid to clip against (i.e. the grid whose extents the source grid will be clipped to) in the Clip to Grid pull-down list. If this is a multi-banded grid, select the appropriate band from the adjacent pull-down.

3. Select the Clip Action. This can be either:

• clip to the extents of the secondary grid or

• remove/blank the area underneath the secondary grid.

4. The output will be presented in the Preview window; use Save As to generate the output clipped grid


Clip

Surfaces>Grid Utilities>Clip

Clip a grid to a bounding polygon or rectangle.

Clip parameters in the Grid Utility dialog

Select the Clipping region type:

• RectangularSpecify a rectangular clipping region by clicking the + and – buttons next to the grid Min and Max X and Y corner extents.


• PolygonalSpecify a MapInfo table containing the polygon to clip against. The polygon may represent a tenement or project area. Alternatively, select a polygon in the grid map window from an existing layer or the cosmetic layer.

Select the Clip grid to region clipping action to remove the portion of the grid which lies outside of the clipping region. Select the Blank grid underneath region action to remove the portion of the grid which lies inside the clipping area.

Note that when a grid is clipped, where possible the size of the grid is minimised and nulls and unused whole rows or columns removed. This can substantially reduce the size of a large grid if only a small portion is extracted.

Convert

Surfaces>Grid Utilities>Convert

Selected grids can be converted (or exported) to an alternate grid format. The formats available are:

• Arc/ESRI ASCII

• BIL

• Encom GRD

• ERMapper

• Geosoft

• ASEG GXF

• MapInfo MIG

• Minex

• Surfer

Note A clipping polygon can also be created by selecting the Pointer mode tool and defining a rectangle in the After preview window by holding and dragging the left mouse button.


• Vertical Mapper

No parameters are used for this option. Select the file required to be converted and then click the Save As button. From the Save as type pull-down list, nominate the output file format required and assign a location and name. If no file extension is specified, the output file is created with the default file extension.

If the converted file format is ERMapper, Vertical Mapper, MIG or GeoTIFF a dialog may be displayed with a prompt to choose a projection for the output grid. The projection selected is embedded into the output grid file so the grid can be imported directly into third party software packages that support these grid file formats.

The projection selected must be the same as the original source grid (this tool cannot be used to transform coordinate systems). Use the Discover>Surfaces>Grid Utilities>Reproject utility to transform a grid into another coordinate system.

Create RGB

Surfaces>Grid Utilities>Create RGB

The Create RGB utility allows three grids (assigned to the primary colour bands Red:Blue:Green) to be combined to produce a single RGB image. These images are generally used to display multi-component data such as spectrometry (for example, Potassium, Uranium and Thorium).

The input grids can be Range Clipped by either a single percentile, multiple percentiles or multiple value ranges. Data within the specified range will be assigned a value of between 0 and 255. Input data below the bottom clip will be assigned a value of 0, whilst data above the top clip will be assigned a value of 255.

The Thresholding option assigns an output value of 255 to all input data within the specified clipping range. All data outside this range is assigned a value of 0. This will produce an image of up to 8 colours (black, white, red, green, blue, yellow, cyan and magenta).

Note The GeoTIFF Image output is not compatible with non-earth or custom affine transformation projections.

Note If a projection is not selected, the output grid will still open correctly in MapInfo. Failure to select a projection will mean that projection details will need to entered manually when the output grid is imported into a third party software program


Curvature

Surfaces>Grid Utilities>Curvature

The Curvature utility calculates the curvature of a surface at each cell centre. Three types of curvature grids are available:

• Profile curvature is estimated along the direction of maximum slope

• Plan curvature is estimated across the direction of maximum slope

• Surface curvature is computed as the difference between the Profile and the Plan curvatures.

The method used to create the curvature grids is as follows.

Curvature is computed for the centre cell (e0) within a 3x3 kernel such as:

The first step is to estimate the coefficients D through H of a quadratic polynomial equation that fits the 3x3 window.

z = Ax^2y^2 + Bx^2y + Cxy^2 + Dx^2 + Ey^2 + Fxy + Gx + Hy + I

where

D = [(e4 + e5)/2 - e0] / CellSize^2E = [(e2 + e7)/2 -e0] / CellSize^2F = (-e1 + e3 + e6 -e8) / 4xCellSize^2G = (-e4 + e5) / 2xCellSizeH = (e2 - e7) / 2xCellSize

The Profile Curvature is estimated along the direction of maximum slope and is computed as:

Profile Curvature = -2 [(DG^2 + EH^2 + FGH) / (G^2 + H^2)]

Note As with all Grid Utilities that handle multiple grids, each input grid must have the same projection, data extents and grid cell sizes.

e1 e2 e3

e4 e0 e5

e6 e7 e8


The Plan Curvature is estimated across the direction of maximum slope and is computed as:

Plan Curvature = 2 [(DH^2 + EG^2 - FGH) / (G^2 + H^2)]

The Surface Curvature is the difference between the Profile and Plan and is computed as:

Surface Curvature = -2 (D + E)

A positive curvature indicates that the surface is upwardly convex at that point, whilst a negative curvature indicates that the surface is upwardly concave. A value of zero indicates that the surface is flat.

Cut/Fill

Surfaces>Grid Utilities>Cut Fill

The Cut/Fill utility summarizes the areas and volumes of change that have occurred between two surfaces. For two grids of the same area at different time periods (i.e. temporally related), a grid or vector file can be created representing the regions where material has been added, removed or remained unchanged.

To use:

1. Select the first/initial grid in the top grid list - it will be populated in the Before grid area.

2. Select the final grid from the After Grid pull down list (if a multi-banded grid is selected, choose the appropriate band from the adjacent pull-down).

3. Set the Output Type, either:

• Cut/Fill Classes – an output Grid or Vector file will be created. Each grid cell or vector region will have a value indicating the change type:

0 – no change in volume

1 – material has been added (Fill)

2 – material has been removed (Cut)


The output vector file (.TAB, .MIF or .SHP) will also be attributed with the cell Count, Area and Volume change for each region. The option Make generated regions hollow will produce uncoloured vector regions.

• Volume Differences – an output grid will be created, with each grid cell indicating the volume difference (negative for volume cut/removal, positive for volume fill/addition) between the Before and After grids

4. Press the Save As button and select the output file name, location and type.

The following additional values will be displayed within the Cut/Fill dialog when the Before and After grid is selected:

• Fill Volume (1) – the volume where the After grid is above the Before grid.

• Cut Volume (2) – the volume where the After grid is below the Before grid.

• Volume Change – the volume difference between the two grids (the Fill Volume minus the Cut Volume).

Edit

Surfaces>Grid Utilities>Edit

Select and modify individual data values in a grid. The Edit utility displays all the grid cell values in spreadsheet row and column format.

Select the Pointer mode button in the preview area and move the cursor over a grid cell in the preview window. The spreadsheet is automatically re-displayed to show the data values of the selected grid cell and the surrounding grid cells. If the level of zoom is inappropriate, select the magnifying glass zoom in or out buttons and adjust the view.

To enable more accurate selection of a grid cell check the Show selected cell in preview box in the Settings dialog. The cursor location in the preview window is now displayed as a large cross-hair.

To modify a selected grid cell, double-click inside the spreadsheet cell and enter a new value.

Note As with all Grid Utilities that handle multiple grids, each input grid must have the same projection, data extents and grid cell sizes.


Selected grid cell and displayed data value available for editing

Right-clicking on a cell provides the following options from a pop-up menu: Copy Selection, Paste, and Fill Selection. The Fill Selection option allows the currently selected cells to be populated with either a constant user-defined value or null value.

Fill value dialog


Fill Holes

Surfaces>Grid Utilities>Fill Holes

The Fill Holes utility is used to replace nulls in a grid by interpolating the surrounding data values. Two Fill Holes options are available:

• Fill internal holes onlyOnly internal holes or null grid cells which are not connected by nulls to the outer edge of the grid are given a new interpolated value.

• Fill internal holes and nulls surrounding gridAll null grid cells in the grid are replaced with interpolated values.

The method used to fill holes involves progressive interpolation from the outer rim of the hole towards the centre until the entire hole is filled. This process can be slow for large holes.

Flip

Surfaces>Grid Utilities>Flip

Flip a grid horizontally and/or vertically. Two flipping options are available:

• Flip horizontallyThe order of the columns in the grid is reversed to produce a horizontal flip.

• Flip verticallyThe order of the rows in the grid is reversed to produce a vertical flip.

No change is made to the number of rows or columns of a grid in this operation and the extent and origin of the grid in unchanged.

Merge

Surfaces>Grid Utilities>Merge

The Merge grid tool allows multiple grids (overlapping or non-overlapping) to be combined into a single output grid. A number of data handling options are provided for overlapping cell values. This tool requires all grids to be in the same projection (use the Reproject Grid utility to convert grid projections).


Within the Merge grid dialog area, select the source grids from the pull-down list and use the Add button to add these to the Grids to merge window below. Selecting grids from this pull-down list will not force a refresh of the preview screen each time a grid is selected, which is useful when dealing with large grids. The preview screen can be manually refreshed using the Update button. Grids can be removed from the Grids to merge window using the Remove button.

A primary grid must be highlighted in the Grids to merge window; the Merge tool will use this grid’s cell dimensions for the output grid.

A range of Overlap combining methods are provided for handling of overlapping grid cells:

MinimumMaximumAverageSumGrid order

Grid Order

To adjust the ordering of layers, use the Up and Down arrow buttons next to the list. The first grid in the list will be the top-most value used if it overlaps with other grids. The last grid in the list value will only be used when no other grids overlap it."

Outline

Surfaces>Grid Utilities>Outline

The Outline utility allows the bounds of multiple grids to be outlined as polygons in a single output vector file. Each bounding polygon is attributed with the source grid file name, and its minimum and maximum X and Y coordinates.

This is a useful way of visualising the extents of multiple regional airborne surveys, such as aeromagnetic and gravity surveys.

This tool requires all selected grids to be in the same projection (use the Reproject Grid utility to convert grid projections).

Note As with all Grid Utilities that handle multiple grids, each input grid must have the same projection.


Overlay

Surfaces>Grid Utilities>Overlay

The Overlay utility enables grid cells to be classified using polygons or polylines from a specified MapInfo TAB or MID/MIF vector file. The dialog is enabled once an appropriate vector file (polyline or polygons) is opened using the Browse button.

Grid cells may be attributed with a Constant overlay value by entering a numeric or text value into the Overlay value window. If the polygons or polylines in the vector file contain attributes then choose the Overlay value from field option and select the attribute field from the Value field pull-down list. All grid cells are located within a polygon or polyline will have an output value equal to the overlay value of that polygon. Cells which are outside polygons or polylines in the vector file can be assigned a null value, the value of the input grid (unchanged) or a user-defined constant value.

The method used to determine if a grid cell is located within a polygon, is whether the centre point of the cell is located within the polygon. Note that some partially covered cells may not be included due to this. To increase the accuracy you can use the Resample utility to decrease the cell size.

In addition to the use of polygons in the input vector file, polylines and point objects are also supported. A Buffer zone may be specified by the user to control how wide these objects appear in the overlay output. The default buffer zone of 0 means that a polyline will create an overlay that is approximately one grid cell wide. e.g. A buffer value of 15 will create a line overlay with a width of 30 metres (15 metres each side of the line). Points will result in a circular coverage with a radius equal to the buffer zone.

If the buffer zone value is non-zero then polygons will also have their boundaries extended by the amount specified.


Overlay grid options in the Grid Utility dialog

Replace

Surfaces>Grid Utilities>Replace

Replace all instances of a specified grid cell value with a new value.

This operation is especially useful when manipulating null values within grids. The value of a Null may differ with different grid formats but the Grid Utility compensates for this.


The dialog allows a +/- Tolerance to be specified. An entered value allows the replacement process to vary about a range centred on the substitution value. For example, if a replacement value of 50,000 was used with a +/- Tolerance of 10, then all values found in the grid between 49,990 and 50,010 would be replaced by the defined replacement entry.

Reproject

Surfaces>Grid Utilities>Reproject

Surface grids can be reprojected between projected (e.g. UTM), geographic (e.g. Lat/Long) and custom coordinate systems. This operation relocates the various pixel locations in the grid through an interpolation method to match the requested output coordinate system.

In the .TAB file associated with a registered grid the coordinates for the grid extents are stored as both real-world coordinates and grid pixel coordinates along with the coordinate system details. When a grid is reprojected to another coordinate system, a new grid and .TAB file is created containing the real-world coordinates in the new projection and the new coordinate system details. The following example details how to reproject an elevation grid from UTM projection AMG Zone 55 (AGD84) into MGA Zone 55 (GDA94) projection.


The Reproject dialog and associated controls

1. Select the source grid from the list of available grids at the top of the Grid Utility dialog. This will populate the Source coordinate system with the grid’s projection.


2. Use the Choose button under the Target coordinate system window to select the output projection using the Category and Category Members options.

3. Select an Interpolation Method from the following:

• Bilinear - the value of a grid cell in the new grid is assigned the weighted value of the four surrounding grid cells in the original grid.

• Bi-cubic – uses the weighted value of 16 surrounding grid cell values in the original grid to interpolate the value a grid cell in the new grid. This method requires more processing but is more accurate than bilinear interpolation. Bicubic interpolation also produces a smoother grid.

• Nearest Neighbour - simple interpolation whereby the new grid cell value is taken from the closest grid cell in the original grid.

4. Click Update after selecting an interpolation method.

5. Select a name for the reprojected grid file by clicking on the Save As button.

By default, a new reprojected grid file and .TAB file are created using the original grid name and a “_reproject” extension. To change the output file name, click on the new name and modify. Click Save to create the reprojected grid files.

Note If the tool cannot recognise the grid projection, use the Choose button to select the appropriate source projection. Alternatively, ensure that this grid is in the front mapper window before opening the Reproject tool to automatically populate this projection.

Note The projection list available in the Discover Grid Reproject utility is stored in a separate file to the MapInfow.prj file. Therefore not all the projections in the MapInfow.prj will be available for selection in this utility. If you wish to reproject grids into a custom coordinate system which has been added to the MapInfow.prj file then copy the custom projection line into the Encom.prj file located in the .\\Program Files\Encom\Common\Projections folder.


Resample

Surfaces>Grid Utilities>Resample

The Resample utility enables new grid cell dimensions to be calculated for a grid. Specify a New cell Height or a New cell width for the interpolated cells. The height and width are the same as Discover can only use square grid cells.

Resample control parameters in the Grid Utility dialog

Note Check the Use NTv2 grid-shift method if available box when reprojecting grids between NAD27 and NAD83 Canadian coordinate systems or AGD66 and AGD84 Australian systems. If you are not familiar with this method see Reference Manual: NTv2 Transformation for more information about this option.


To create a resampled grid three interpolation methods are available:

• Bilinear - the value of a grid cell in the new image is assigned the weighted value of the four surrounding grid cells in the original grid.

• Bi-cubic – uses the weighted value of 16 surrounding grid cell values in the original grid to interpolate the value a grid cell in the new grid. This method requires more processing but is more accurate than bilinear interpolation. Bicubic interpolation also produces a smoother grid.


These interpolation methods use a transformation (for scaling), where the row/column values [u,v] describe a transformed plane and [x,y] the original grid data plane. To determine the samples of the transformed grid g([m,n]) from the samples of original f([k,l]) the following steps are applied:

• Calculate c([k,l]) from the grid values at each f([k,l])

• For each [m,n] of the transformed grid find corresponding source location [x,y] in the input grid

• Compute f([x,y]) using the spline model, where g([m,n]) =f([x,y])

For the resampling of a grid to a new cell size and comparing the fits using φn([m,n]), the order on the nth term determines the method applied where n=0 (nearest neighbour), n=1 (bilinear), n=3 (bicubic).

Jagged or sharp edges using a nearest neighbour interpolation progressively smooth out in higher order spline-interpolation. Bicubic spline interpolation is popular as cubic splines appear smooth to the human eye.

After a cell size and method have been chosen, click the Update button to force the preview processing to proceed and review the result in the preview pane.

Rotate

Surfaces>Grid Utilities>Rotate

Rotate a grid a specified angle. An angle that is positive causes the rotation to be clockwise and a negative angle will rotate the grid anti-clockwise. Grids may be rotated about the grid centre or the bottom-left hand corner. Three interpolation methods are available for the rotated grid cell values:


• Bilinear - the value of a grid cell in the new image is assigned the weighted value of the four surrounding grid cells in the original grid.

• Bi-cubic – uses the weighted value of 16 surrounding grid cell values in the original grid to interpolate the value a grid cell in the new grid. This method requires more processing and is more accurate than bilinear interpolation. Bicubic interpolation also produces a smoother grid.


Rotation of a grid and the Before and After results shown in the Preview panes


Shift

Surfaces>Grid Utilities>Shift

The Shift utility enables the origin of a grid to be moved horizontally and/or vertically. Specify an Offset from the original grid X or Y origin or enter New grid origin X and Y coordinates manually Once the shift parameters are entered click the Update button to display the new grid origin in the After preview pane.

Slope

Surfaces>Grid Utilities>Slope

The Slope utility analyses the eight cells surrounding each grid cell and determines the slope angle in degrees or the slope direction for each grid cell. The slope angle or direction is then stored as the cell value for the output grid.

The slope direction is measured in degrees from the grid Y axis. The slope angle is the average slope of the surrounding grid cells at each grid cell. The slope percentage is the change in grid elevation divided by the grid cell spacing multiplied by 100. A percentage of 100 is equivalent to a slope angle of 45 degrees (the height change across the cell equals the cell width).


Grid slope control parameters


Split

Surfaces>Grid Utilities>Split

The Split utility enables the individual bands of a multi-banded grid (including RGB grids) to be output to single band grids.

Statistics

Surfaces>Grid Utilities>Statistics

This tool calculates a range of standard Statistics for grid cells enclosed or intersected by any objects in a vector file, either totally or partially overlying a grid. The vector file can be composed of a mixture of object styles.

The grid statistics which are computed include:

• Number of cells

• Number of valid cells

• Number of null cells

• Minimum value

• Maximum value

• Mean value

• Range

• Standard Deviation

• Sum (addition of all grid cell values intersecting the object)

• Percentage of null cells

For large grids, only the preview tile area statistics will be displayed until the Save As button is used to process the full grid and save the results.


Grid Utility Dialog showing Statistics options

If a unique identifier field exists for each vector object (e.g. sample number, rock code, etc), this field can be set as the ID Field. The attributes in this field will be used as an identifier in the output file for each vector object., The Objects to process option allows the user to either create statistical output for all object types in the vector file, or one style in particular (points, lines or polygons).


The browser output from the Statistics utility

The Save As button will create a new MapInfo vector file named vectortablename_stats), with each input object attributed with its calculated statistics (as well as the ID Field if specified). These statistics can also be exported to either a Comma delimited (*.CSV) or Tab delimited (*.TXT) file using the Export statistics button.

This is an excellent tool for prospectivity analysis; for example, assigning statistics to geological or tenement boundaries from a regional soil or lag grid of copper values. The output polygons could then be thematically mapped:

Thematically mapped geology polygons using mean copper values assigned using the Statistics tool


Surface Area

Surfaces>Grid Utilities>Surface Area

The Surface Area utility calculates the total 3D surface area and 2D planar area for a grid. It also calculates the roughness of the surface, which is the surface area divide by the planar area. A perfectly flat grid (i.e. where every grid cell has the same value) will have a roughness of 1.

The values for the total grid are reported in the dialog in the same units the grid is defined in. Individual grid cell surface area or roughness values are saved to the output grid.

Usage examples of this tool include:

• comparing the relative roughness of different DEM/DTMs

• calculating the actual topographic surface area of a catchment/drainage basin, for 'run-off' studies

• analysing the effects of different filters or gridding techniques on the 'topography' of the grids

Vectorize

Surfaces>Grid Utilities>Vectorize

The Vectorize utility will convert a single grid into a vector file of one or more polygons, using one of the following modes:

• Generate one rectangular region for each grid cell

Each grid cell of the input grid is converted into a square polygon in the output MapInfo TAB or MID/MIF file, attributed with the grid cell value. Each output region cell is assigned a grey-scale colour value based on the input cell value using a simple linear stretch on the data range.

• Generate a region for each discrete grid value

Note The preview for either the surface area or roughness will look almost identical with histogram equalization applied, but the value of the grid cells will be different.


Each unique value in the grid is analysed for contiguous areas and a polygon boundary drawn around these. This will produce a vector map with polygons bounding areas of homogenous grid values, each attributed with the unique region valuer. Each output region is assigned a grey-scale colour value based on the input cell value using a simple linear stretch on the data range.

• Generate a region for each group of non-null values

This produces a separate polygon for each contiguous area of valid (non-null) grid data. For instance, a series of polygons outlining coastlines could be generated from a DEM by first using the Classify Grid Utility to set all grid cells with sea level heights (and lower) as 'Nulls', then Vectorizing the resulting grid using this mode.

• Generate a region for the grid extents

Produces a polygon outlining the area covered by the grid cells. This creates the same result as using the Outline Grid Utility, except only for a single grid.

The option Make generated regions hollow will produce ‘empty’ vector regions without any fill colour or pattern.

It is recommended that large grids are resampled (see Resample) to a larger cell size prior to using the Vectorize utility to reduce the number of vector polygons.

Viewshed

Surfaces>Grid Utilities>Viewshed

The Viewshed utility computes the view-shed from one or more locations of a specified height above the grid to an observer at a specified height (terrain offset) above the grid. The areas of the grid that lie within the line of sight are saved to a new grid. This is a useful tool when considering, for instance, the spatial coverage provided by a series of telecommunication or repeater towers, or the positioning of fire observation platforms.


Grid Utility Dialog showing Viewshed options


The Height or z-value is the height of the view-point origin above the specified grid; this may represent a structure such as a transmission tower.

The Maximum distance is the radial extent around the viewshed origin or tower. The line of sight is calculated for each grid cell within this radius.

Sweep Angle and Azimuth controls are available, limiting the view from a Viewshed Origin to the specified bearing range.

Setting a Terrain offset adds the specified value to each grid cell (e.g. the height of a receiver or person) and is incorporated into the line of sight calculation.

The curvature of the earth can also be taken into account when calculating the view-shed by specifying a Curvature Model. If this option is selected, the grid distance unit needs to be selected to allow the scaling of the earth’s radius to the correct units.

A Gaussian smoothing filter can be applied to the line-of-sight grid to eliminate spurious lines caused by small irregularities in the input grid. The calculated line-of-sight grid values may also be classified into one of two options:

• 2 (in/out)Denotes whether a cell is visible or not from the viewshed origin.

• 3 (in/fringe/out)Denotes whether a cell is visible, not visible or on the fringe when viewed from the viewshed origin.

Two Output types are available:

• Grid – if multiple viewshed origins are used (via a .TAB or .MIF file), the tool can Create a separate coverage grid for each viewshed origin. The output grids will be suffixed with the ID Field (if assigned), otherwise a 1, 2, 3, etc suffix will be used.

The Viewshed origin is the location from which the line of sight is to be calculated. The X and Y position of the Viewshed origin can be manually entered or selected by clicking the arrow tool and selecting a location in the “Before” or “After” preview windows. Alternatively, one or more viewshed origins or tower positions can be specified by using a MapInfo TAB or MIF file containing point locations. This TAB/MIF file may optionally include the following fields: sweep azimuth, sweep angle, height, maximum distance and ID field. These optional fields can be specified for the appropriate parameters (below) allowing each viewshed origin to have differing values (e.g. different tower heights and ID’s) instead of a single Constant value.


• Polygons – can only be selected if the Perform Gaussian Smoothing option is enabled. This will produce a polygon outlining the extent of the viewshed (or combined viewsheds). The polygon table incorporates a Coverage field, indicating the percentage of the total input grid (null and non-null cells) covered by the polygon. If multiple viewshed origins are used (via a .TAB or .MIF file), the tool can Create a separate coverage polygon for each viewshed origin. The output table will incorporate an ID field, which will be populated with either the specified ID Field (if assigned), or an integer value (1, 2, 3). The Compress polygons option reduces the number of nodes in the output polygons by applying Tomek compression (removing details which are smaller than the cell width). This option is only available for the 2 (In/out) Value Classification.

Volume


The Volume utility computes the volume between two grids, or between one grid and a constant Z value. Examples of use include calculating the volume between:

• the water table and a mining surface

• a DEM (top surface) and the same DEM after open-cut mining (Overlay a series of attributed polygons representing mining benches) (bottom surface)

• upper and lower depth surfaces for a heavy mineral layer in mineral sands

• a DEM and the DEM modified with a new airstrip

This tool requires both grids to be in the same projection (use the Reprojectutility to convert grid projections) and have the same cell size (use the Resample utility).

For large grids, only the preview tile area statistics will be displayed until the Process button is used to process the full grid.

Note For best results with this tool, it is recommended to enable the Histogram Equalisation and Look-Up Table options.


Grid Utility Dialog showing Volume calculation

The volume between the two grids is calculated by subtracting each bottom grid cell Z value from the corresponding top grid cell Z value and then multiplying by the top grid cell width (X) and height (Y). Each individual grid cell volume is then added together to compute the final volume. If a constant Z value is used, this is subtracted from each cell Z value in the grid and used to calculate the volume.

The following volume calculation options are available:

1. Compute volume of main grid above secondary grid: only those cells where the main grid lies above the secondary grid are used to calculate the volume


2. Compute volume of secondary grid above main grid: only those cells where the secondary grid lies above the main grid are used to calculate the volume

3. Compute total volume between the two grids: all overlapping cells are utilized to calculate the volume, regardless of which grid in is top. The difference between cell values is treated as absolute i.e. all values are positive.

4. Compute volume of main grid above constant Z value

5. Compute volume of main grid below constant Z value

The planar area calculated for the main grid selected is also displayed. This can also be calculated using the Surface Area utility.

Dividing Grids into Tiles

Reference Manual: Surfaces>Grid Tiler

Grid Tiler dialog


The Grid Tiler allows large grids to be sub-divided or tiled into a number of equally sized smaller grids. This is useful when a grid file is either too large to open or import into MapInfo, or too large to modify or interrogate with the Surfaces menu tools.

To subdivide a large grid:

1. Open the Grid Tiler (the source grid does not have to be open within MapInfo)

2. Using the File Open button at the top right of the dialog, select the source grid file (if the grid is already open within MapInfo, select it from the top pull-down list). A preview of this grid will be shown along with the grid size information

3. In the Tile Layout section, set the number of tiles to divide the source grid into in both the East-West and North-South orientations. See Tile Layout for further information.

4. Ensure that the Create .TAB option is enabled in order to automatically create a MapInfo .TAB file for output tiled grid. It is also recommended to enable the Create .GHX option, to allow the precalculation of grid statistics for more efficient grid handling (see Pre-computing Grid Statistics for more information)

5. By default the output grid tiles will be created in the same directory as the source grid: this can be modified in the Tile Naming section.

6. The output tiles will be named by adding a suffix to the input file name. A number of suffix options exist – see Tile Naming below for more information.

7. Select the output Tile Format (formats available are ERMapper, BIL, Encom or Surfer grid formats and press Create Tiles. The grid tiles will be automatically registered in the same projection system as the input grid file.

Tile Layout

In addition to setting the number of tiles to create along the X and Y axes, you can instead define the size of the tiles by the distance (width or height) or the number of cells (rows or columns). An Overlap can also be defined between adjacent tiles as a percentage of the distance (width or height), or by a number of cells (rows or columns). The overlap interval is applied to both sides of each tile (east and west or north and south).


If the size of tiles does not divide evenly into the input grid dimensions, the edge tiles will extend slightly past the source grid bounds. The Crop to grid option will crop these tiles to the extents of the input grid. The Origin can be set to the Top left or Bottom left so that these edge tiles will be located at the Bottom or Top row of the grid. Cropped are always located at the right side of the grid.

Tile Naming

The suffix applied to the output tiles can either be a Name-Column-Row or Name-Row-Column format. For either format, the initial tile Origin (i.e. 01x_01y) must be specified as either the bottom left or the top left corner tile.

The E-W or N-S components (i.e. Column and Row suffixes) of the output tile suffix can each independently have either a numeric or character format. Additionally each component can have individual prefixes and/or suffixes. The preview of the entire Tile name suffix is shown in the example box.

Assigning Values from a Grid to Map Objects

Surfaces>Assign Values from Grid

The Assign Values from Grid menu option assigns grid cell values from the grid to map objects that overlie them. Grid values can be assigned to both line and region object types. This function could be used to assign elevations to sample points or to drillhole locations from a digital elevation model or to assign mean geochem values from a geochemistry grid to overlying geology polygons.

To assign grid values to point objects select a column in the table to store the assigned values.

Assign grid values dialog


To assign grid values to overlying polygon or polyline objects, select the map objects from the map window first. In the Assign Grid Values dialog select the column or columns to store the grid values from the pull-down lists. Discover can assign the mean, minimum or maximum grid cell value to each object.

As well as assigning the values to columns, the values can be reported to the screen.

Pre-computing Grid Statistics

Surfaces>Precompute Grid Statistics

The Precompute Grid Statistics dialog with multiple grid processing in progress

When a grid file is first opened by Discover, a summary statistics file (.GHX) is automatically created. Summary statistics files allow Discover to handle larger grids (1GB+) efficiently, and also significantly improve the speed of grid visualisation (i.e. colour /sunshading modification via the Modify Grid Display tool).

The automatically created .GHX file calculates the summary statistics for a specified percentage of the grid file (as set under Discover>Surfaces menu> Grid Handler Preferences). For smaller grids the entire grid is analysed by default (i.e. 100%), whilst for larger grids a smaller default percentage is used to allow rapid .GHX file creation. These default sampling percentages should allow .GHX files to be created for most grids (regardless of size) in less then a couple of minutes.


If more comprehensive statistics are required for larger grids, it is NOT recommended to significantly increase the default sampling percentages in the Grid Handler Preferences, as this will impact on the grid loading time into MapInfo. GHX file creation time is proportional to the sampling percentage: multi-gigabyte sized grids may take tens of minutes to a few hours when sampled at 100%.

Instead, use the Precompute Grid Statistics tool to precalculate detailed GHX files for one or more large grids prior to opening in MapInfo (e.g. perhaps overnight)

To calculate statistics for one or more grid files:

1. The Input for the Precompute Grid Statistics tool can be either a single grid file or a directory path (+/-any subfolders). Use the browse button (top right of dialog) to select a single grid file. If all files in a directory are to be sampled, enable the All in Directory option (plus the Subdirectories option if required), then use the browse button to select the target directory.

2. If specifying a directory to sample, a number of Criteria can be set. These include limiting the target grids to a particular grid format, a minimum file size (MB or column/row count) or age.

3. Sampling sets the proportion of the grid dataset for which summary statistics will be calculated: the calculation time is proportional to the percentage set. The sampling is done on a row-by-row basis, for example 50% will sample every second row in the grid file and calculate statistics based on this. Use Defaults will load the default sampling settings from the Grid Handler Preferences. All 100% will set complete (100%) sampling regardless of the grid size. A linear interpolation of the sampling value is used for grids in each size category. For example a grid with 7500 rows will have a sampling percentage half way between the Medium and Large sampling percentages

4. When ready, press the Compute Statistics button. The Progress table will display for each grid being sampled relevant information whilst the statistics processing is in progress.

5. Once the .GHX file/s have been created, the grid file/s can be opened into MapInfo/Discover rapidly - the automatic .GHX creation process has been bypassed.

Note Files will only be added to the progress list once processing has started on the file.


Grid Handler Preferences

Surfaces>Grid Handler Preferences

Grid Handler Preferences dialog for reading grid files

The Grid Handler Preferences dialog provides the following:

1. Initial visualisation options when a grid is first loaded into MapInfo/Discover

2. Sampling proportions used to calculate the summary statistics file (.GHX) when a grid is first loaded into MapInfo/Discover

3. Toggles for the various Grid Handlers.

Initial Display

This section controls the initial visualisation of a loaded grid:

• Colour defines what colour table (LUT) is applied: select from any available colour table in the Discover LUT directory

• The Stretch is the colour method applied, either histogram or linear.


• The Sun Angle and Highlights enables Sun shading and Sun highlighting.

• Preload Zoom will load the higher resolution view for one pyramid level of the current grid view. This makes zooming in and out quicker but increases memory usage.

Statistics Sampling

When a grid file is first opened by Discover, statistics sampling is performed to automatically create a Summary Statistics file (.GHX). Summary statistics files allow Discover to handle larger grids (1GB+) efficiently, and also significantly improve the speed of grid visualisation (i.e. colour /sunshading modification via the Modify Grid Display tool).

Statistics Sampling sets the level of statistics sampling performed based on the grid size (as defined by the number of rows in the grid). The sampling is done on a row-by-row basis, for example 50% will sample every second row in the grid file and calculate statistics based on this. A linear interpolation of the sampling value is used for grids in each size category. For example a 7500 row grid will have a sampling percentage half way between the Medium and Large sampling percentages.

If more comprehensive statistics are required for larger grids, it is NOT recommended to significantly increase the default sampling percentages in the Statistics Sampling section, as this will impact on the grid loading time into MapInfo. To precalculate more accurate .GHX files for larger grid files, utilise the Precompute Grid Statistics tool.

Vertical Mapper Colour Support

Enabling the Allow Colour Table Writing to Grid option will force any colour changes made in the Modify Grid Display dialog to be written directly back to a Vertical Mapper .GRD file.

Grid Handlers

A grid file can be read using either a:

• Grid handler (.GH* file) - allows query and modification of a grid's colour scheme and statistics to be performed on the grid.

• Raster Handler (.RH* file) - displays data as a static layer. Grid data cannot be queried or modified dynamically. However data rendering is slightly faster than when using Grid Handler.


Encom-developed handler files are all named with a prefix 'Encom'. To enable or disable the use of a particular handler file simply tick/un-tick the Use box.

Note Specific handlers should only be disabled if you experience problems loading or visualising particular grid formats. We recommend contacting Encom support before doing so.

Note The Encom Grid handlers use a pyramid method to display large grids at a lower resolution for different zoom levels. The initial single low resolution view of the grid has a fixed size. When you zoom in, the grid is divided into 4 regions which are loaded at twice the resolution. This process is repeated until the full resolution of the grid is displayed by many 'tiles'. A limited number of 'tiles' will be cached in memory.

17 Hydrological Surface Analysis 735

17 Hydrological Surface AnalysisThe generation of stream network and watersheds from a topographic grid surfaces (e.g. DEM or DTM) is required in many disciplines including mineral exploration, environmental monitoring, hydrology and engineering. The tools on the Discover Surfaces>Hydrology menu can be used to assist with the planning of new stream sediment sampling programs, or determine if previous conducted surveys have satisfactorily sampled an area. They can also be used to normalize the analytical results of a survey to stream basin area, slope and aspect to determine likely source location for dispersion. In addition these tools can be used to identify erosion prone areas, wetness indices, potential fuel accumulation for managing forest fire risk and many other terrain based analysis.

• Hydrology Workflow

• Removing Unnatural Pits

• Extracting Drainage Features

• Generating Catchment Areas

Hydrology Workflow

The Hydrology tool workflow follows several steps starting from a raw topographic grid surface. Each step can be run independently or as part of a continuous process. The steps are:

1. Remove pits to ensure hydraulic connectivity within the watershed. See Removing Unnatural Pits.

2. Compute flow direction (slope aspect) and slope (gradient) grids. See Flow Direction.

3. Generate the contributing area (flow accumulation) grid. See Flow Accumulation.

4. Delineate stream network vectors based on stream order threshold. See Define Stream Channels.

5. Delineate watersheds and sub-watershed vector regions for each stream segment in the network.


This workflow can result in the following fully attributed MapInfo Professional vector files:

• Stream outlets and stream junctions points.

• Stream network polylines attributed with their hierarchial stream order, stream segment length and junction nodes.

• Watershed/catchment polygon boundaries for each stream segment or each stream outlet.

• Catchment polygon boundaries for user-speciifed outlet locations

The processing steps involved (some steps have been omitted for clarity) are shown graphically below:

Note A watershed is the upslope area contributing flow to a given location. Such an area is also variously referred to as a basin, catchment, sub-watershed, or contributing area. A sub-watershed is simply part of a hierarchy, implying that a given watershed is part of a larger watershed.


1. Source digital elevation model (DEM) 2. Calculation of a flow direction grid surface

3. Generation of a Flow Accumulation grid surface 4. Applying a threshold contributing area value to generate a Flow Threshold grid surface

5. Vectorisation of steam networks, with hierachial stream order attributes

6. Delineation of watershed boundaries as polygonal regions


Removing Unnatural Pits

Surfaces>Hydrology>Fill Pits

Pits or depressions areas in a topographic grid surface that are completely surrounded by higher terrain and can be a relatively common artifact of the interpolation methods used to create them. Pits are rare in nature, but do occur (e.g. lakes or dams), so a pit filling utility must have the capability of filling “unnatural” pits or depressions as well as leaving natural ones. Unnatural pits or depressions must be removed from the topographic grid surface prior to the creation of drainage networks because they are dead ends to flow and result in a disconnected drainage network.

A 2D representation of the pit fill routine. The pit is filled to the level of the lowest adjacent cell.

The pit fill process involves 'flooding', or filling up, depressions in the topographic grid surface by detecting cells, or groups of cells, that are lower than all surrounding cells. These cells are then raised to the elevation of the lowest surrounding cell (known as the 'pour point').


A typical topographic grid surface. The grid contains numerous pits (as artefacts of the grid surface interpolation) which would disrupt the drainage network if not filled. Several pits are nested inside each other.

The topographic grid surface after pit fill. All the pits are now filled in and drainage can now flow smoothly through the network.


To remove unnatural pits in a topographic surface:

1. On the Surfaces menu, select Hydrology>Fill Pits.

2. In the Select DEM box, select the source topography grid from the list.

3. If any grid regions are to be excluded from the pit filling process (such as lakes, dams, etc), click the Open button at the top right of the dialog to locate the polygon table outlining these areas, selecting <MapInfo files> in Files of type box. When loaded, select this file in the Polygon Exclusion Mask box.

4. The elevation range to be pit filled can be limited using the Ignore Elevations controls. For example, to exclude areas below sea level in a bathymetry grid, set Ignore Elevations < to 0.

5. Click the Update button to preview the resulting grid. Depending on the size of the topographic grid surface, the preview may take some time to generate. Progress will be displayed in the Execution Log and progress bars.

6. In the After preview box, choose one of the output types to preview: mask, pits or filled.

7. In the Output box, click the Save As button to specify an output location and grid name. By default the output grid is created in the source file directory with a _pitfill suffix added.

8. Click Process. Progress will be displayed in the Execution Log and progress bars. Close the Pit Fill dialog box when processing is completed.

Extracting Drainage Features

The Extract Drainage Features tool will automatically extract drainage features from a DEM grid and out put these as either raster or vector files. Streams and their corresponding watersheds can be delineated from a DEM based on a minimum catchment area threshold and watersheds can be created for each outlet or stream segment in the network.

To extract drainage features automatically:

1. On the Surfaces menu, select Hydrology>Extract Drainage Features.

2. In the Select DEM box, select a topographic grid from the list.


The following processes are available in the Process section; each process is dependent on the preceeding processes:

• Pit Fill grid generation. More advanced pit filling is available via the separate Pit Fill tool (see Removing Unnatural Pits).

• Flow Direction grid generation (see Flow Direction).

• Flow Slope grid generation.

• Flow Accumulation grid generation (see Flow Accumulation).

• Flow Threshold grid generation.

The level of detail for which streams are delineated is controlled by the minimum catchment area threshold. Specify a value which represents the minimum contributing area you require for your stream network. If you choose to create one catchment per outlet then no catchment will be smaller than this value. If sub-catchments are being generated for each stream segment in the network then the minimum catchment area will only be guaranteed for the source catchments. Some sub-catchments may be smaller than the threshold in areas where they enclose downstream junctions.

• Stream junction and outlet points, stream network polylines and watershed polygons will be created as vector files.

Set the stream ordering method (see Define Stream Channels) to either Strahler or Shreve in the Classify box.

3. Select the check boxes under the Exec column to select which processes to execute. If any of these steps have been carried out previously on the selected DEM, they will be automatically selected in the Done column; you will be prompted to overwrite the previous files during processing.

Note It is recommended to use a pit filled grid as the input DEM if available (as generated by the Pit Fill tool outlined above). However, pit filling can be carried out within the Extract Drainage Features tool, but this provides no controls for polygon exclusions or elevation clipping.

Note It is important that the minimum catchment area is appropriately defined for your DEM and analysis needs. Specifying smaller values will result in more stream segments and significantly longer processing times.


4. Select the check boxes under the Open column to indicate which outputs you want to open as MapInfo tables after processing is completed.

5. Click the Update button to preview the output. Depending on the size of the topographic grid surface, the preview may take some time to generate. Progress will be displayed in the Execution Log and progress bars.

6. In the After preview box, choose one of the output types to preview (pit filled, flow direction, flow slope, flow accumulation, flow threshold).

7. Click Process. Progress will be displayed in the Execution Log and progress bars.

Output files will be named after the input topographic grid with an appropriate suffix for each process, and saved in the same folder as the input topographic grid.

The Extract Drainage Features dialog utilising a pit filled DEM to generate all multiple output grid and vector files.


Flow Direction

This step takes a topographic grid surface as input and outputs a new grid which represents the flow direction from each cell to one of its 8 neighbours (either adjacent or diagonally). The most common and simplest methodology for representing the flow direction is to divide each cell into eight segments and compute the vector of maximum slope to determine the direction of flow into one of the eight adjacent cells. This approach is generally referred to as the single flow direction or the 8-direction (D8) flow model. The direction of flow is determined by finding the direction of steepest slope from each cell. This is calculated as the change in height value divided by the distance.

An encoding scheme used to represent the flow directions in the output grid. Each cell is attributed with a code representing the adjacent cell that is in the direction of steepest slope.

A pit filled topographic grid surface prior to flow direction processing.


The flow direction grid created from the topographic grid surface. The value in each cell represents an adjacent cell in the direction of maximum slope.

There are several limitations to the D8 model, namely that it produces coarse drainage networks because of the discretization of flow directions into only one of eight possible directions. The method is also unable to accurately represent divergent flows (e.g. on a hill slope with convex curvature) due to the assumption that each cell can drain to only a single neighbour. These simplifying assumptions make the process more efficient, so D8 is still the most common methodology used in GIS applications.

Flow Accumulation

This step calculates the accumulated flow (upslope or contributing area) as the accumulated weight of all cells flowing into each downslope cell in the output grid. The accumulated flow area of each cell is taken as its own area (one) plus the area of upslope neighbours that have some fraction of their flow draining into it. This is usually calculated recursively starting at each outlet point. The flow from each cell either drains entirely to one neighbour (if the flow angle falls along a cardinal or diagonal direction) or proportionally between two cells, according to how close the flow direction angle is to the direct angle to the upslope cells.


The flow accumulation grid. The value in each cell represents the number of cells that flow into it.

Define Stream Channels

Stream channels are determined from the flow accumulation grid as cells which have a large number of upslope cells. Because there can be many cells which have upstream cells it is standard practice to apply a threshold value to the flow accumulation grid tracing the stream network to eliminate small or unwanted streams. Determining an appropriate threshold value for extracting stream channels is highly dependent on terrain morphology and factors such as contributing area climate, slope, soil characteristics etc.


Stream ordering is a method of assigning a numeric order to links in a stream network. This order is a method for identifying and classifying types of streams based on their number of tributaries. The most common systems used to determine ordering are the methods proposed by Strahler and Shreve.

In both methods, the most upstream stream segments, or exterior links, are always assigned an order of one. In the Strahler method, stream order increases when streams of the same order intersect. Therefore, the intersection of two first-order links will create a second-order link, and the intersection of two second-order links will create a third-order link. The intersection of two links of different orders, however, will not result in an increase in order. For example, the intersection of a first-order and second-order link will not create a third- order link, but will retain the order of the highest ordered link. The Strahler method is the most common stream ordering method in use. However, because this method only increases in order at intersections of the same order, it does not account for all links and can be sensitive to the addition or removal of links.

The Shreve method accounts for all links in the network. As with the Strahler method, all exterior links are assigned an order of one. For all interior links in the Shreve method, however, the orders are additive. For example, the intersection of two first-order links creates a second-order link, the intersection of a first-order and second-order link creates a third-order link, and the intersection of a second-order and third-order link creates a fifth-order link.

Because the orders are additive, the numbers from the Shreve method are sometimes referred to as magnitudes instead of orders. The magnitude of a link in the Shreve method is the number of upstream links.


Generating Catchment Areas

Individual catchments for user-specified outlet points can be generated using the Extract Catchments tool. The input locations for catchment outlets may be a river mouth, dam or lake, or even sample points and river junctions.

To generate catchment areas for known outlet catchment points:

1. On the Surfaces menu, select Hydrology>Extract Catchments.

2. In the Select DEM pull-down, select the source topographic grid from the list. This tool requires the following grids to be available, which are generated with the Extract Drainage Features tool:

• Pit Fill grid (see Removing Unnatural Pits)

• Flow Direction grid (see Flow Direction)

• Streams network vector file (see Define Stream Channels)

3. Click the Open button at the top right of the dialog to locate the points table which contains outlets for the catchments, selecting <MapInfo files> in Files of type box. When loaded, select this file in the Select Catchments Outlets box. This could be river outlets into the ocean or a lake, or it could be various sample points along a river network, to analyze the contributing catchment areas.

4. Select the Snap Outlets to Streams option, and specify the Snap Buffer (in grid cells). This is the distance an outlet point can be moved during processing to coincide with a stream network. Any outlet points that do not coincide with a stream polyline after snapping has been applied will be ignored during the catchment generation process.

5. The Preview area can be configured to display a combination of a grid and multiple vector files. This is a useful way to experiment with the Snap Buffer distance. Click Update Catchments to update the preview, including changes to the Snap Buffer distance.

6. Use the Save As button to specify a location and name for the output file. By default this is the same as the input grid, with a _catchment suffix added.

7. Press Process to generate the catchment polygon file.

18 Working with Structural Data 749

18 Working with Structural Data• About Structural Data

• Displaying Structural Data as Orientated Symbols

• Digitizing Structural Data

• Dip and Plunge Angles

• Discover Structure Codes

About Structural Data

Structural data, such as bedding, lineations, or synclines, can be displayed as oriented structural symbols from a symbol library. Discover offers two different ways to handle structural data.

• Table DataStructural measurements can be read from columns in a native MapInfo table. This method provides a simple method for creating as many symbols as necessary in the one pass.

• Digitized DataStructural measurements can be digitized into a map window one at a time. This is useful when there are measurements on a map that have not been transcribed to a file. In this case, the measurement location is taken from the digitized point (using a digitizing table or from the screen) and a dialog box is displayed requesting input for structural data for that location.

Structural Symbol Fonts

The structure symbols are stored in a TrueType font that is available from the MapInfo Symbol Styles libraries along with the other TrueType symbol fonts that ship with MapInfo and Discover. If the symbol font is unavailable Discover will plot normal text instead of the structure symbols. The True Type fonts are installed during the Discover installation procedure. If the fonts are unavailable in MapInfo, check the Windows Control Panel>Fonts directory to see if the fonts are installed.

For more information about structural symbol fonts, see Reference Manual: Map Styles and Symbol Fonts


Displaying Structural Data as Orientated Symbols

Discover>Structure Symbols

The Discover>Structure Symbols utility is designed to display structural data as oriented structural symbols from a symbol library. The structural measurement data can be read in from a data file or input directly with the digitizer/mouse and keyboard.

Select Structure Symbols from the Discover menu. The Structural Symbols dialog is displayed.

Structural Symbols dialog

Select the required Data Input by option. Choose Process from Table to use an existing table containing structural information in an appropriate format. Choose Digitize into Mapper to add structural measurements to an existing table. Choose Digitize into New Table to automatically create a new table with the appropriate structural data columns. If you wish to process data from a read-only Table (e.g Access database) or Mapper layer, select the option Make a native copy of the selected table.

The structural data table must have numeric columns for the following data:


• Easting and Northing of measurement location

• Dip Direction or Strike of measurement

• Dip or Plunge

• Discover Structure Code

Example of structural information in a browser

The name and position of the columns in the table are not important.

When digitizing data into a new table, Discover can create a table with the appropriate columns defined. If there is a map window open the new table is added to this window and automatically assigned the current map window coordinate system. If there are no map windows open, nominate the coordinate system to use for the new table from the Choose Projection dialog.

The input data may also include other useful information such as sample numbers, site ID, lithology etc. This information is not used by Discover in the creation of the structural data points.

Select the table to use from the Structural Data Table list. Use Open a table to open an existing table or to create a new table. Click OK to display the Structural Data Mapper dialog.


Structural Data Options

The Structural Data Map Window dialog

Discover provides three structural symbol font files for Australian, Canadian and US structural symbols. These are available as symbol libraries from the Structural Mapping Type pull-down list:

• Australian Structural Symbols (modified by AGSO)

• Canadian Structural Symbols (modified by the GSC)

• USA Structural Symbols (modified by USGS)


The MapInfo>Options>Symbol Style also provides access to these symbol libraries referred to as ET_Structural, ET_Structural_Canada and ET_Structural_USA respectively. A full table of symbols for the Australian, US and Canadian symbol sets, together with Discover structural codes and keyboard codes, is available at the end of this section and in Appendix C of this reference manual.

Choose the appropriate symbol library to use and if this library is different to the library used previously, Discover will ask for confirmation that this is the correct symbol style library to use.

Specify Azimuth Method

Choose how the Azimuth data is to be specified:

• Specify azimuth as Dip Direction – use this option if the structural data has been collected using Dip and Dip Direction measurements in the field

• Specify azimuth as Strike using right hand rule - use this option if the structural data has been collected using Dip and Strike measurements. All strikes are converted to dip directions by adding 90º.

Many structural codes measure the direction of plunge rather than a strike or dip direction (for example lineations and fold axes). For these codes the azimuth information is always used as plunge direction regardless of whether strike or dip direction has been selected.

Select Data Columns

Use the pull-down list next to each structure column to nominate which columns in the structural data table contain the required data. If digitizing new structural data points, their attributes will be added to these columns.

Symbol and Label Style

Discover provides control over how the structure symbols will be displayed. Select from the normal symbol formatting options including symbol size, colour and style (such as bolding). As the structural symbols are TrueType font symbols the normal text formatting control over the appearance is available. The symbols are scale invariant so that they remain the same size on the screen (or paper) regardless of the map scale.


The dip/plunge text can be displayed either as MapInfo object labels or as text objects stored in the cosmetic layer. The Dip/Plunge as MapInfo labels option uses the normal MapInfo method to produce scale invariant labels. When object labels are created in this way, they must be saved with a workspace if the labels are to be used at a later date. The Dip/Plunge as text in cosmetic layer option enables the text size to be relative to a specified output scale. Therefore, the text must be resized if the data is to be viewed at a different output scale. The cosmetic text objects can be saved to a new table using the Map>Save Cosmetic Objects menu option.

In many instances horizontal (0) and vertical (90) structural measurements are denoted by different structural symbols, however in some cases the same structural symbol is used. Check the Show labels at 0 and 90 to display the dip label for these orientations.

Click the OK button to create the structure symbols. If the Process from Table option was selected a message window will be displayed detailing how much processing has been completed. The structural data points are then displayed in a map window.

Digitizing Structural Data

DigStruct>Plot Symbol

If one of the digitizing options was selected a new DigStruct menu is added to the MapInfo menu bar when the OK button is clicked from the Structural Data Mapper dialog.

The output table should be in the front map window and be editable. The structural measurement can be digitized as either a point at the required location (using the MapInfo Point/Symbol drawing tool) or as a line (using the MapInfo Line tool).

As a point or line is digitized, the data entry dialog is displayed. If a line is digitized the Dip Direction, Plunge or Strike azimuth of that line is automatically displayed in the appropriate box. Only the Structure Type and the Dip need to be entered.

Note When digitizing a line, Discover uses the start point on the line as the location for the structural symbol on the map.


Entering Structural Data for a new Point

The Symbol/Label Style is set to the previously selected options in the Structural Data Mapper dialog. These settings can be modified for individual structural measurements. The easting and northing of the digitized point, dip direction/strike/plunge, dip angle and structure code are inserted into as attributes into the table when the structural symbol is created.

Dip and Plunge Angles

A dip or plunge value may be entered for most of the structural types that Discover supports. Selected structural types such as wrench faults, trend lines, monoclines, etc. cannot have a dip value.

Discover expects a value to be entered for dip between 0 and 90. However, there are instances where a dip has not been measured for a variety of reasons. As dip values are stored in numeric columns blank dip measurements are stored as zero, indicating a horizontal structure.

When digitizing structure measurements, leave the dip entry blank to indicate no dip measurement was taken. Discover will store a value of –99 in the dip column for blank entries. If processing structural measurements from a table, ensure that values of –99 have been inserted into blank entry cells in the correct fields. If Discover finds a null dip value, no dip label is displayed.


Discover Structure Codes

Structure symbols are based on those described in the Australian Geological Survey Organisation (AGSO) mapping style guide with the addition of extra symbols such as schistosity, L1-L3 lineations and general trend lines. A full table of symbols for the Australian, US and Canadian symbol sets, together with Discover structural codes and keyboard codes, is given in Reference Manual: Map Styles and Symbol Fonts. These codes are provided in both a numerical and alphabetical order.

Note For a number of structure types, such as bedding or cleavage, Discover uses different symbols to indicate horizontal and vertical dip.

Discover Code Description

1 Bedding

2 Overturned bedding

3 Bedding Facing

4-6 Cleavage s1 - s3

7 Not currently used

8 Lineation (general)

9-11 Lineation L1 - L3

12 Bedding-Cleavage Intersection

13 Crenulation

14 Mineral Alignment

15 Banding/Platy Alignment

16 Joint

17 Foliation

18-20 Anticline f1-f3

21-22 Anticlines (Overturned and Recumbent)

23-25 Syncline f1-f3


26-27 Synclines (Overturned and Recumbent)

28-30 Normal Faults

31 Thrust Fault

32-33 Shear Zones

34 Fault Zone breccia

35 Trend Line

36 Parallel lines

37-38 Veins (open and closed)

39-41 Oriented drill collars

42 Fault gouge

43-44 Wrench Faults

45 Columnar Joint

46 Bedding (facing unknown)

47-48 Undulating/Deformed bedding

49-51 Foliation d1-d3

52-54 Bedding/Cleavage parallel s1-s3

55-56 Plunge of Bedding/Cleavage (s1-s2) intersection

57 Plunge of Bedding/Vein intersection

58 Monocline

59-60 Minor Anticline

61-62 Minor Syncline

63-64 Minor Fold

65 Kink Fold

66-67 Asymmetric Fold vergence

Discover Code Description (Continued)


68-69 Fold vergence

70-71 Recumbent Fold Vergence

72-74 Minor Fold Vergence

75 Boudin plunge

76 Chert contortions plunge

77 Mylonitic foliation

78 Eutaxitic foliation

79-80 Glacial Striae

Discover Code Description (Continued)

19 Tenements 759

19 TenementsThe Tenement module provides an interactive interface for searching existing tenement data and creating new applications, with a web link for downloading regular tenement updates.

• Download regularly updated Australian tenement data via a web-based subscription service.

• Query tenements by date, licence type and holder information.

• Create applications with interactive State and Datum selection.

• Create polygonised block and sub-block reference grids.

• Create new or modify existing applications by selecting sub-blocks manually or interactively, including sub-block counter, limit and area checks.

• Generate application reports automatically for entry into standard statutory application forms.

To open the Tenements menu:

• On the Discover menu, click Tenements Menu.

The Tenements menu is added to the MapInfo menu bar.

For information on how to use the Tenements tools, see:

• Apply for an Australian Mineral Tenement

• Displaying Graticular State Reference Grid

• Searching Australian Tenements


• Downloading Tenement Data

Apply for an Australian Mineral Tenement

Create new or modify existing applications by interactive sub-block selection, and generate application reports automatically for entry into standard statutory application forms.

Tenements>Application

To make an application:

1. On the Tenements menu, click Application. The Australian Tenement Application dialog box is displayed.

2. Under Select State, select a state from the map. When a state is selected the corresponding datum is also selected. For example, selecting WA will select the GDA 94 datum.

If a datum is selected that does not comply with the current state legislation, then the application may be invalid.

19 Tenements 761

3. If not previously configured, click Configure to set a workspace or table. On the Configure dialog box, select Load base table or workspace and type a path for either a MapInfo Table or Workspace. Click OK to save and return to the main dialog.

4. From the Australian Tenements Application dialog box, click OK. The table or workspace specified in step 3 is opened, and the Define Application dialog box is displayed, from which you can define the method of application and the tables to be used for application (see Application Tables).

5. In the Application directory box, click the Save button to select (or type the folder path name) where the application files will be saved. The tables created during the application process include Application Table, Block Table and Label table.

6. For a new application, under Application region, select Create new and type the application region name. For example, typing Darlot creates a MapInfo table named Darlot.TAB.

To modify an existing application, select Modify existing, and click the browse button to select the application table in the adjacent box.

7. Under Application method, select either:

• Define interactively: select sub-blocks from a mapper window.


• Manually define: select sub-blocks manually. This method is not available for Victoria, Tasmania and South Australia applications.

8. Click Settings to turn on and off the auto-labelling of blocks and sub-blocks.

9. Click OK to create the application. The application tables are created or updated and placed in the current map window.

For Victoria and Tasmania applications, which use a Universal Transverse Mercator (UTM) Map Grid of Australia (MGA) grid system, the UTM Zone dialog box is displayed to select the correct UTM Zone.

10. Depending on the Application method selected, select blocks and sub-blocks. See Interactive Block Selection or Manual Block Selection.

11. At completion of block selection, for all states except WA, a summary text report is displayed. The summary report includes the map sheet, block number, sub-block letter, bounding coordinates, datum, state, total area, and total subblocks/graticules. These details can be copied and pasted onto the official application forms, which are typically PDF or Microsoft Word formats.

For Western Australia, the forms (Form 21 Attachment 1 and Form 21 Attachment 2) are presented as MapInfo tables.

All tables required for the tenement application are stored in the Discover tenement directory, which is defined with Discover>Configuration>Settings, typically C:\Program Files\MapInfo\Professional\Discover\Tenements.

19 Tenements 763

Application Tables

Application table

The application table contains the following fields:

• SubBlock: Block Identification method (BIM) letter

• Map: Map Sheet name either 1:1,000,000 or 1:100,000

• Block: Block Identification Method (BIM) block number

• Merged: Defines the record status, N denotes a single sub-block, Y denotes a merged polygon of all the sub-blocks

• Area: Area or sub-block in km2

Block table

The block table stores application block polygons and gridlines for blocks and sub-blocks. The block table contains the following fields:


• BlockNumber: Block number for selected application

• RecType: Type of gridlines

Label table

The label table stores application corner points for the total application area. The Label table contains the following fields:

• PointID: Number of point

• Latitude: Y coordinate or point

• Longitude: X coordinate or point

• AreaName: Application Region Name

• Map: Blank field for user to update with mapsheet if required

Interactive Block Selection

This selection method is enabled when Define interactively is selected on the Define Application dialog box. The Select Application Area dialog box is displayed, which displays the current sub-block selection, sub-block limit and area selected for the selected state.

Click the selection tool and then select or deselect blocks and sub-blocks in the map window. The selection information is dynamically updated with the selected sub-block count and total area selected.

19 Tenements 765

Click OK to finish block selection. A number of checks are performed for sub-block count, total area and non-contiguous blocks. Warning messages are displayed if conditions applicable in the selected state are not met by the selection.

Manual Block Selection

This selection method is enabled when Manually define is selected on the Define Application dialog box. The Manually Define Sub Blocks dialog box is displayed, from which you can select blocks and sub-blocks on a map sheet.

Click the 1:1 million mapsheet box and select the map sheet, type the block number in the Block number box, and then select the sub-blocks from the matrix. Click All to select all subblocks in the selected block. Selected sub-blocks are shown in the Selected sub-blocks box. To add sub-blocks from other sheets repeat the process until all the desired sub-blocks appear in the Selected Sub-Blocks box.

To delete a block, select the block in the Selected sub-blocks box and click Delete Block.

Click OK to finish block selection. A number of checks are performed for sub-block count, total area and non-contiguous blocks. Warning messages are displayed if conditions applicable in the selected state are not met by the selection.


Displaying Graticular State Reference Grid

Create polygonised block and sub-block reference grids.

Tenements>Draw State Grid

To display the state graticular reference grid:

1. On the Tenements menu, click Draw State Grid. The State Grid dialog box is displayed.

2. Under Select State, select a state from the map. When a state is selected the corresponding datum is also selected. For example, selecting WA will select the GDA 94 datum.

19 Tenements 767

If a datum is selected that does not comply with the current state legislation, a warning message is displayed.

3. Under Region, in the Name box, type the name of the region.

4. In the Folder box, click the Save button to select (or type the folder path name) where the grid files will be saved.

5. Click Settings to turn on and off the auto-labelling of blocks and sub-blocks.

6. Click OK to draw the graticular grid.

For Victoria and Tasmania, which use a Universal Transverse Mercator (UTM) Map Grid of Australia (MGA) grid system, the UTM Zone dialog box is displayed to select the correct UTM Zone.

Gridline, Block, and Sub-Block layers are created and drawn in the current map window. The tables created are prefixed with the Region Name and suffixed with either _Grid, _Block, or _SubBlock.


Searching Australian Tenements

Tenements>Tenement Search

Tenement data downloaded with the Download Tenement Data tool (see Downloading Tenement Data) can be searched with the Tenement Search tool.

To search Australian tenements:

1. On the Tenements menu, click Tenement Search. The Tenement Search dialog box is displayed.

2. In theTenement Table box, select the tenement table to be searched. The tenement layers available in the Tenement folder are listed. The Tenement folder is defined by Discover>Configuration>Settings and is typically located under C:\Program Files\MapInfo\Professional\Discover\Tenements.

19 Tenements 769

3. Under Select holder, select the type of holder search:

• None: Do not restrict search by holder.

• Individual search: Search by tenement holder name.

• Keyword search: Search by keyword or text string. In the Holder column box, select the search field in the tenement table, or select <All>.

• Alias search: Search by holder group alias. Click Configure to view or define alias groups (see Manage Tenement Tables and Holder Aliases).

4. Under Select date select the type of date search (application date, granted date, or expiry date) and the date range.

• Under Licence type option select one or more types of licence to be searched (application, granted and moratorium).

• Under Selection display select how the results of the search will be displayed:

• Browse Selection: display in browser.

• Map Selection: display in map window.

• Zoom map to Selection: zoom map window to the selected search results.

• Selection Statistics: display search summary in browser, including number of tenements records returned, total area of tenement polygons in km2, area of smallest tenement polygon in km2, and area of largest tenement polygon in km2.

5. In the Name Selection box, type a name for the search.

6. Click Search to start the search.

Manage Tenement Tables and Holder Aliases

On the Tenement Search dialog, click Configure to display the Configure dialog box, from which you can create, edit and delete tenement tables and holder aliases.


Tenement tables

To create a new table:

• Click New to display the Tenement Table dialog box, from which you can select the folder location and table name.

To edit a table:

• Select the table in the Tenement tables box, and then click Edit. The Tenement Table dialog box is displayed, from which you can edit the folder location and table name.

To delete a table:

• Select the table in the Tenement tables box, and then click Delete.

Holder Aliases

A holder alias allows the selection of multiple holder values from a tenement table with an alias name.

To create a new alias:

1. Click New to display the Define Holder Alias dialog box, from which you can select the folder location and table name.

2. Select the alias in the Holder alias box, and then click Edit. The Define Holder Alias dialog box is displayed.

3. In the Tenement table box, select a tenement table.

4. In the Holder field box, select the field containing holder names.

5. In the Holder alias box, type the holder alias name.

6. Under Select holders, use the controls to move holders from the Available box to the Selected box, and vice versa.

7. Click OK to save.

To edit an alias:

1. Select the alias in the Holder alias box, and then click Edit. The Define Holder Alias dialog box is displayed, from which you can edit the alias settings.

19 Tenements 771

2. The alias settings are displayed, which can be edited.

3. Click OK to save changes.

To delete an alias:

• Select the alias in the Holder alias box, and then click Delete.

Downloading Tenement Data

Tenements>Download Tenement Data

Pitney Bowes Business Insight provides an online subscription service for Australia-wide mineral tenement data. Before using this service, you must subscribe and obtain a user name and password. To subscribe, contact PBBI at:

Email: [email protected]

Sydney phone: +61 2 9957 4117

Perth phone: +61 8 9226 0101

To download Australian tenement data:

1. On the Tenements menu, click Download Tenement Data. The Download Tenement Data dialog box is displayed.

mailto:[email protected]


2. To setup the web server connection details, click Settings.

Use the Proxy tab for corporate internet access through a Proxy Server:

• Use System Settings. Use the Local Area Network (LAN) settings in the system registry. You can review the current LAN settings from the Windows Control Panel (Start>Control Panel>Internet Options>Connections Tab>LAN Settings).

• Use Direct Connection. Override the system LAN settings and connect directly to the Internet (not through a proxy server).

• Use Proxy Server. Use the settings defined under Proxy server settings.

Use the WFS tab to change the connection timeout settings:

• Timeout. Increase this value if you are experiencing timeout problems because of a slow internet connection.

• Read/write timeout. Increase this value if you are experiencing timeout problems when downloading tenement data from the Envinsa Online Services (EOLS) Server.

3. Click Login to connect to the EOLS server. Type your User name and Password, and click OK to log in.

When the connection is made, the Download Tenement Data dialog box is updated.

19 Tenements 773

4. Under Layers, select a layer. The layer details are displayed under Coordinate system and Layer description.

5. In the Preferred view box, select how the dowloaded data is displayed.

6. Click Download to download the selected layer to the file specified in the Table file name box. To change the default download path, use Discover>Configuration>Settings.

7. You will be prompted to log on to the EOLS server to finalise the download process.

Note The same tenement data folder is used by the Tenement Search tool.


8. The data will either be displayed in a mapper browser or not displayed in MapInfo following the download process.

Index 775

Numerics3D

Coordinate Drillholes 557DXF files 53

3D displays 3393D Gridding

Convert null values to background 5793D Scatter plot

GraphMap 372

AAbsolute path name 9Accept 290acquire

Database Import 35Actual

Map Size 285add

frame titles 313line and point labels 318scaled frame 300section to layout 533shade file button 271shade file list 270text labels 313

Add Derived ColumnGraphMap 378

Add or Delete 307Additional Text Label Options 317Advanced Settings

3D Gridding 580Affine

Custom Projection 166Simple Data Transformation 162Transformation 162

aggregatesassigning aggregates from points to enclosing

polygons See Assign ValuesAlign

Objects 209Alter

Map Bounds 116

anglesdip and plunge 755

Animation 331Create 332Movie File 336

anisotropygridding using elliptical search 596kriging model variogram 624

AnnotationLine 324trench 490

appendmulti-table 130

ApplyGrid Filter 661

applyColour Map 266

apply density corrections control 593Apply Styles from List 305arithmetic operations

of grids 642ASCII

advanced import 36supported formats 39

ASCII gridexport 95import 75

AssignValues 224

Assign Values from Grid 728Australian Structural Symbols 752Auto

Data Entry 124Auto open after save option 662, 694AutoCad 53Auto-clip Stretch 647AUTOGRID 296Autogrid

Map 24Mask 299Table 300

Automatic Legend Generationdescribed 309

Index


prerequisites 307specifying the order within a legend 311

autoscaling of Z-axis option 679Auto-Shade 259

Apply 271Other Discover Functions 271saving thematic settings 269transferring shade settings between Discover

installations 271Use Other Files 271

Auto-Shadefacility 269AVI

movie file format 336Azimuth method

specify 753

Bbackground image

GraphMap 390Band Interleaved by Line 81Bar chart

GraphMap 372Bearing and Distance

trench survey table 446Bi-cubic

resample grid 713BIL grid

import 81Bilinear

resample grid 713Bivariate view

gridding Statistics Explorer 615block kriging

Gridding Tool 590boolean field

GraphMap 369, 392boundary

digitizing 539Box Border 310Box plot

GraphMap 373breaklines

Gridding Tool 576browser window

GraphMap 381BT2

Gemcom import 54

BufferGridding Tool output 604

BuildObjects from Table 192

buildcolour table 264map for colour table 268

Build Objects 192

CCalculate

Volume for a level 686calculate

maximum and EOH values 560calculate the volume 686Calculate Volume for a Level 686Canadian Structural Symbols 752cell dimensions

grids 712cell parameters

grids 601Change Direction

reversing the direction of polylines and polygons 220

Change Line Direction 220Child table

GraphMap 397Choose New Columns button 271Classify

GridUtility 695Clear assignments

GraphMap 369Clear Cells button 651Clip

grid 698clip

grids 697, 705image 433

Clip to 222Polygon 222

clipping a grid 688, 689Clipping Data Tables 223clipping objects

at a polygon boundary 222Clipping Options 222Close

All 107

Index 777

coincident pointsGridding Tool 577

Collartrench/costean 444

collartable 441

colourbuild table 264edit pattems 524edit table 265load pattems 531thematic map 264

Colour cells of a row 651Colour code sample assay labels 317colour lookup tables

colouring polygon data See Colour MapsColour Map

apply 266Colour Maps

building colour lookup tables 262, 264editing colour lookup tables 265thematic maps using colour lookup tables 266using standard colour lookup tables 260

colour table 265ColourMap 260ColourMaps>Colour Map 271Column

Multiple Update 126Column Delimited 194Column parameter

GraphMap 380Column Update 126combine

grids 705Command Search

hide and show 3settings 4using 3

compositingdownhole 545

ComputeArea Change 228Slope or Aspect Grid 686

Compute Area Change 228Compute Slope or Aspect Grid 686Concave Hull

grid clipping 604

Configure 286Configure button on the Scaled Output dialog 286Container 225

Contents 225, 226Contents 226

Container 225, 226Contour

DXF export 53Interval 666Level File 666Line 667

contourgrid surfaces 444

contour grid 665Contour Line

Label 667contours

generating from a grid 665convert

grids 699image 435, 437version 2.1 grid 94

Convert null values to background3D Gridding 579

Convert Vector to Grid File 637Convex Hull

grid clipping 604cookie-cutting polygons See Processing Inlying Polygons

Coordinatereproject 168Transform 158Update Mode 158

coordinate systems 21Coordinate Transformation

transforming data between two coordinate systems 158

Coordinate Update Mode 158Coordinates 157

Node Edit Node 201Nodes 199storing/updating current object coordinates

157, 196Update 157

Copying workspace to CD-ROM 10correlation coefficient

geochemistry 153


correlation matrixgeochemistry 153

Cosinus kernel functiondensity grid 600

costean See trench 486Create

A Scalebar 302Additional Scaled Outputs 292Animation 332Drillhole Sections 440Grid button 691Map Legend 307Scaled Output Map 284SeeThru Shading 322Stack Profiles 352Surface 602thematic map layer 267Voronoi Polygons 683

createColour table 262grid 571new drillhole project 451, 452, 454, 456, 459New Legend 526section collar plan 538structure symbols 750

Create Expression 644Create tab

GraphMap 366creating

a trench view 487Current Mapper Projection 21Cursor Position

Position 28curvature

grids 701curvature utility 701cusstom projections

Drillhole section plans 495, 536Custom

Re-Order Mode 311Custom option 651Custom scheme

GraphMap 408cutting objects

with a selected line See Line Cut

DData

Digitizing 120Entry (Auto) 124Manual Attribute Entry 123

datahandling 137

data columnsselect 753

Data ConditioningGridding Tool 579

data coveragegrids 602

Data Format 348Temporal Trends 348

data handling 137Data handling options

GraphMap 377data handling options

GraphMap 377data levelling

Geochem 146data selection

GraphMap 391Data tab

GraphMap 391data window

GraphMap 374database

validate drillhole 459Datamine

Import 42import 43, 44

Datamine ASCIIexport 45

Datashed databaseimport 46

DataSightimport 46

DBMS 109Auto Refresh 109

decimal degreesgrid spacing 298

definelog display 519new section or plan 473

Delaunay triangulationGridding Tool 598

Index 779

Density and Orientation 323density correction

inverse distance weighting 593Density grid

Gridding Tool 598Depth From and Depth To 443Dervied Columns, creating

GraphMap 378desurvery

drillholes 557DeviationSurvey

WinLoG Import 100Dialog

GridUtility 690DigData 120digitize

Structure Symbols 754Digitizing

Data 120digitizing

boundary 539dip and plunge

angles 755direction

changing direction of a line See Change Direction Direction

storing direction of a line See Line DirectionDiscover

menus 1structure codes 756toolbars 2

Discover Code 756Discover Mobile

export 269DISCOVER.Prj 20display

log 518log parameters 521options 478

display options 478Display order 183Distance and Bearing 21

Location Display 22Distance Calculator 155Distance grid

Gridding Tool 600Distance, Bearing 199

DocumentLink Setup 279Link to Map Object 280Linking 278Open Linked 282

donutting polygons See Processing Inlying Polygons

downholecompositing 545info tool 539survey table 442

downhole datatrench/costean 491

downhole data tables 443downhole survey table 442downhole table

trench/costean 448download

data table 443draped

vector layers 679Draw

Grid Profile 676Line 198Object 196Polyline/Polygon 199Pont 197

drawsection grid 537

Draw Arc, Ellipse and Rectangle 200draw grid labels 299Draw Grid option 285, 288drillhole

collar table 441create new project 451, 452, 454, 456, 459Create Sections 440data format 441project setup 450, 464, 469

drillhole collar 441Drillhole Display

collar location 441drillhole display 441drillhole project

create new 451, 452, 454, 456, 459Drillholes 439

3D coordinates 557Costean 486


desurvey 557Export 96Import 96Saved Settings 564Subset Project 471Trench 486

Drillholes > Sectional Resource Calculator 542Drillholes subsystem

and resource computation 540Drillholes>Add section to layout tool 294, 295drive wall

creating a section or plan 486Duplicate button

of LUT Editor 652DXF 50

export contours as 53import 51

DXF file 53DXP

Drillholes 96Dynamic ScaleBar 23

EECW

import 69edge ticks 298Edit

Node Coordinates 201edit

colour pattems 524colour table 265grids 703

edit colour table 266Edit Map 307Edit Node Coordinates 201Editor

Workspace 8ellipitical shell 593ellipse

and resource calculation 545elliptical search

Gridding Tool 593elliptical weighting

inverse distance weighting 593enhance

image 430

Enhanced Layer Control 179Epanechnikov kernel function

density grid 599Equal Angle See StereogramEqual Area See StereogramER Mapper 81, 82, 84

grid output 603ER Mapper grid

import 82ER Mapper grids 84ERS

ER Mapper grid header 82ESRI ASCII grid

import 85ET Str font 325ET_Structural 753exact hit distance

inverse distance weighting 593Exit 295experimental variogram

kriging 589Exponential scheme

GraphMap 409Exponential weighting model

inverse distance weighting 592export

ASCII grid 95boundaries XE 53colours pattems 532DATAmine ASCII 45Discover Mobile 269Drillholes 96graph as MapInfo table 358graph as raster image 358MineSight SRG 61multiple MID/MIF 131Profile Analyst Located Image 73Surpac string 64Vulcan archive 66

Export grid 95Expression construction 314Extract Nodes 227

FFavourite

MapBasics 4

Index 781

Tables 103Workspaces 7

Favourite Mapbasics 4Favourite Projections 18Favourite Workspaces 7FFT filters 661field

add 131comparison 131delete 131rename 131reorder 131type 131

field assignmentsGraphMap 367

File>Print 292Files of Type entry 658fill

grid holes 705fill internal holes 661, 705filter

GraphMap 369image 431

Filter field assignmentGraphMap 369

Filter Properties 661filter, saved selection

GraphMap 392Filtered Grid

Save 662Fit Map Window to Selected Object 25Fixed extents 27

in map linking 27Fixed scale 27

in map linking 27flip

grids 705flip a grid 705flow accumulation 744Flow arrows See Vector Viewflow direction 743Font Size defaults 316Format 315

grids 688Text 315

format

drillhole data 441grids 699

formulaof Grid Calculator 643

FrameConfigure 286Settings 286Setup 285

Frame Settings 286Frame Setup 285frame setup 285Frame Titling 313Function pull-down list 691

GGaussian

filters 657Gaussian kernel function

density grid 599Gaussian smoothing filter 603Gaussian weighting model

inverse distance weighting 592Gemcom BT2

import 54generate a profile 679Geochem

data levelling 146point classification 142statisics 151

geological mapscolouring See Colour Mapsinlying polygons See Processing Inlying

Polygonsgeology

surface 444Geometry tab

Gridding Tool 601geophysical point data

trench downhole data 443, 449Geosoft

grid format 86grid output 603

Geosoft databaseimport 55

Geosoft gridimport 86

global


settings 523Graph Builder

GraphMap 367Graph Colouring 352Graph Display 349Graph Query 352graph types

GraphMap 371GraphMap 357, 394

Advanced Colour Options 407Advanced Size Options 410altering symbol display 406colour by group 407colour by RGB value 414Column parameter 380Create tab 366Data Handling Options 377data selection 391Data tab 391data window 374Dervied Columns, creating 378export 358filter 369Global Properties 415graph window tools 359Group field 369Legend Window 414Load Workspace 358MapInfo polygons, importing 395Modify tab 406Multi-Table Relationships 396navigation 389Open dataset 358overlay 394Permanent Selection Region, creating 394Permanent Selection Region, importing 395precondition data 376preconditioning data 376quick access toolbar 359Regression Line 390remove selection 393Reset Layout 416Residuals Graph 390Save Data 358Save Workspace 358selection in MapInfo 393Selection Statistics 405

size by group 410statistics 405Value parameter 380window tools 383

Gridcell 568definition 567file formats 571Function 692Line Intersection 298Method 597Utilities 688

gridcontour Surfaces 444draw section 537

Grid bounds parameters 602grid calculation function 686Grid Calculator 642

description 642Grid Filter 657

Apply 661Information 660Settings 664

grid format conversion 699grid information 639grid offset 689Grid Open button 643Grid Open dialog 643grid parameters

sections 543grid passes

Gridding Tool 595Grid Profile

Draw 676grid query tools 672grid resampling 689, 712grid rotation 689Grid Spacing 298grid style 298Grid to Grid Clip 697, 705Grid Utilities 688grid value editing 703gridding

input tab 576gridding methods 585Gridding Tool 572, 573

Index 783

Geometry Tab 601Input Tab 576Method Tab 585Output tab 603Preview Display 574

grids 565Auto-Apply 573cell dimensions 712clip 698clipping 697, 705combine 705contouring 665convert format 699convert to vector 637create 571create legend 657create LUT 650create RGB 700curvature 701edit 703fill holes 705flip 705Gaussian smoothing filter 603grid information 639gridding methods 585Histogram application 653import grid 74LUT editor 649merge 705modify display 646output formats 603projection 569reproject 709resample 712Rotate 713Shift 715Slope 715smoothing 603Split 717sun highlight 653sun shade 653transparency 648Vectorize 720Viewshed 721Volulme 724

GridUtilityClassify 695

Dialog 690Overlay 707Preview Window 692Replace 708Rotate 713Save output Grid 694Settings 693Shift 715Slope 715Split 717Vectorize 720Viewshed 721Volulme 724

Group fieldGraphMap 369

Group field assignmentGraphMap 369

Group field useGraphMap 370

Group schemeGraphMap 409

Group, saved selectionGraphMap 393

Grouped View button 188

Hhandling

data 137Hatching

transparent hatching See See-Thru ShadingHide and show menus 1high frequency noise

removing from grids 603Hints 294Histogram

GraphMap 372Modify Grid Display 653

histogram equalisationGriddingTool 574

Histogram Stretch 647Hole ID 443horizontal plan

section 477hydrology 735

extract drainage features 740fill unnatural pits 738generate catchments 747


workflow 735

IIDW

Gridding Tool 591image

clip 433convert 435, 437enhance 430filter 431properties 429rectify 418reproject 426rotate 435save control points 423selection 419tool dialog 428

image toolrectify 420

Images 417imperial

scalebars 302Import

ASCII File 37import

Acquire database 35advanced ASCII 36ASCII grid 75BIL grid 81Datashed database 46Drillholes 96ER Mapper grid 82ESRI ASCII grid 85Gemcom BT2 54Geosoft database 55Geosoft grid 86MicroMine 59MineSight SRG 60Minex grid 87multiple MID/MIF 130Profile Analyst Located Image 72Surfer grid 89Surpac grid 87Surpac string 62USGS DEM grid 91Vertical Mapper grid 90Vulcan archive 65

Import and Export 31import grid 74Importing

layered DXF data 51, 54lines from coordinates on one row 195Micromine files 62Polylines delimited by row or column 193XYZ grids 196

importingtables from multiple directories 106

Increment and Constant Values 122info tool

downhole 539Information

Grid Filter 660in GridProcessor 660

Information buttonof Grid Calculator 643

inlying polygonsprocessing See Processing Inlying Polygons

Input TabGridding Tool 576

Insert Nodes 217Interp Selection button 651interpolation methods 713Inverse Distance Weighting

Gridding Tool 591ioGAS

import 57

JJPEG2000

import 69

KKey in shapes 196keying in

object coordinates 196object descriptions by distance bearing 196

krigingequation 589Gridding Tool 587nugget 589range 589semivariance 588sill 589

Index 785

LLabel

Contour Line 667Label Lines checkbox 315Label Style 315LABELLER.MBX 317Labels

creating at an angle 317Line and Point 318sizing to specified map scale 313

labelsAdd Text 313on grids 298

LAS 58Layer

Select All 203layer

create thematic map 267Layer Control Options dialog 186Layers

Profile 679Layout

Add Scaled Frame 300Local Grid 171

layoutsection options 535

Layout>Align 294Legend

Box Boarder 310Create Map 307Order 310Style 310Tables and Columns 308

legendcreate grid legend 657create new 526properties 527, 530

legend creation 309Legend from objects within map window only option 310

Legend Order 310Legend Style 310Legend Window

GraphMap 414levelling

operations 147

LibraryMaintain Styles 307Styles 305

librarySeeThru Shde 323

LIDAR LAS 625, 626, 630import 58

Line 198Annotation 324Change direction 220Concatinate 215Orientation 226

Line and Point 318Line Annotation 324Line Concat 215Line Cut 215

cutting objects with a selected line 215Line Direction

storing as an attribute 226Line graph

GraphMap 372Line on One Row 195Linear scheme

GraphMap 408Linear Stretch 647Linear weighting model

inverse distance weighting 592Lineations

plotting See StereogramLines graph

GraphMap 372Link

Document 278Document Setup 279Document to Map Object 280Open Document 282

Link Document 280Link this map option 27Linking 278

Document 278Fixed extents 27Fixed Scale 27Map 26

ListApply Styles 305

loadcolour pattems 531


Local Gridconverting from See Coordinate

Transformationgenerating 171Layout 171

Local Grid Layout 171Location Display 22log

define display 519display 518display parameters 521

log displaydefine 519parameters 521

Log schemeGraphMap 409

look-up tablegrids 650

LUTcreate for grids 650editor for grids 649

MMaintain Styles 307major axes

of search ellipse 596Make Affine Custom Projection 166Make Custom TitleBlock 301manager

secton 493Manual

Data Entry 123Manual Attribute Data Entry 123Map

Accept Position 290Actual Size 285Alter Bounds 116Autogrid 24Position 289Position Scaled 288Scale 285

Map Autogrid 24map frame

titles 313Map Frame Position offsets 287Map graph

GraphMap 371

Map Grid 296, 297drawing to a map window 296on printed maps See scaled hardcopy outputoverlaying grids based on different projections

300saving 300

Map Link option 28Map Linking 26Map Making Tools 283Map making tools

creating legends See Automatic Legend Generation

Styles Library See Styles LibraryMap Making>Add scaled frame to layout tool 294, 295

Map Position 289Map Scale 285Map Window Tools 1, 15map with no map grid 285, 288Map>Previous View menu option 295MapBasics 4

Favourite 4MapGrid 300MAPINFOW.PRJ 21Mapper State 16mappers linked 26MapSize rectangle 289Margins

Non-Printing 287mask

around grid 299Match Window Sizes 30maximum and EOH values

calculate 560MBX 4Mean scheme

GraphMap 409Menus 1Merge

grids 705Method Tab

Gridding Tool 585Methods

transformation 425methods

Modify Grid Display 647

Index 787

metricscalebars 302

MI Label Angles 317MicroMine

import 59Micromine

importing files from 62MicroStation 53MineSight

import 60MineSight SRG

import 60Minesight SRG

export 61Minex grid

import 87Minimum Curvature

Gridding Tool 586minor axes

of search ellipse 596model variogram

kriging 621Modfy tab

GraphMap 406Modify

MI Label Angles 317Modify Grid Display 646

Histogram 653LUT Editor 649methods 647transparency 648

Movie File 336multi-banded grid 717Multiple

Column Update 126multiple line plots See Lines graphmultiple MID/MIF

export 131import 130

multiple scatter plots See Scatter Matrixmulti-segment pie chart See Pie chartmulti-table

append 130, 131comparison 131field editing 131open 106pack 129reproject 131, 170

Structure Manager 131Multi-Table Relationships

GraphMap 396

Nnatural neighbour interpolation 598Near/Far

grid clipping 604Nearest Neighbour

resample grid 713negative values

display as hole logs 521New button

for LUTs 650New grid origin 715new section or plan

define 473New Shade File

option 270No List option 291, 304Nodes 199

Coordinates 199Distance, Bearing 199Insert 217Node Edit Coordinates 201

nodesediting object nodes 201keying in object nodes 196

Non-Printing Margins 287normal probability plot See Probability plotnormalize

geochemical data 146nugget

inverse distance weighting 592kriging 589

nulls in grids 661, 705Number of entries 650

OObject

Align 209Colouring 272Cut 215Offset 206Transform 207

Object Editing>Key In Shapes 25


Object InformationGraphMap 393

Object Offset function 293Object Style Entry

Add or Delete 307Edit Map 307

objectskeying in object nodes 196

offset a grid 689Offset East 315Offset North 315Offset Object 206Offset Objects

creating copies of objects at a specified offset 206, 275

Open 282Linked Document 282

openmulti-table 106

Open Layout Template from workspace 304opening

tables from multiple directories 106operations

levelling 147Options

Profile 679options

display 478output 143section layout 535structural data 752

ordinary krigingGridding Tool 590

Orientation controlof search ellipse 596

origin of a grid 715Other Discover Functions 271Other Discover Funstions

Auto-Shade 271output

options 143output format

of Grid Calculator 643output options

output type 143point styles legend 145set point styles 144

Output tabGridding Tool 603

output typeoutput options 143

OverlayGridUtility 707Map Grid 300

overlayGraphMap 394

Ppack

multi-table 129Packaging workspaces 10Padding by row and then by column 665padding controls 665Padding in 2D using gridding 665Padding margin 665panning

GraphMap 389parameters

log display 521Parent table

GraphMap 397pattems

edit colours 524export 532load colour 531

Pattern 318Colour Text Labels 318

Pattern Density 323Pattern Library 323Pattern Type 322

SeeThru Shadding 322Pattern Width 323patternsfor see-thru 322Percentile Ranges 647, 674Percentile scheme

GraphMap 409permanently

Colour Map objects 267Pie chart

GraphMap 373Plan curvature 701Plane Transformation 160Plot

Index 789

Vectors 274Plot Vectors 274Point 197point classification

Geochem 142point kriging

Gridding Tool 590point style legend

output options 145Poles to Planes

plotting See StereogramPolyBuilder 230

Additional Utilities 256Attribute Polygons 254Check Linework 241Correct Linework 244Create Polygons 251Digitise Linework 237Extend and Break Linework 244Preferences 235

PolyClipclipping objects at a polygon boundary 222

Polygon Drape 679polygonal grid clipping 699Polygonize 230

PolyBuilder 230Polygons

Clip to 222Clipping Data Tables 223Clipping Options 222Donut 220Split-Multi 223

PolylineSmoother- 212Thin 213

Polyline Smoother 212Polyline/Polygon 199Polylines

Column Delimited 194Line on One Row 195Row Delimited 193

position of the Scaled Output map 289Position Scaled 288

Map 288Power weighting model

inverse distance weighting 592precondition data

GraphMap 376preview display

Gridding Tool 574Preview Window

GridUtility 692Previous View function 181Printer Setup 286Printing 292

Scaled Output Layout 292Probability plot

GraphMap 373Processing Inlying Polygons

and geological maps 220cutting polygons from surrounding polygons

220Profile

Layers 679Options 679

Profile Analyst Located Imageexport 73import 72

Profile curvature 701profile information

and drillholes 444Profile See Surface Analysis 679Profiles

Create Stack 352Proimity

Search 201Projections

display details 21favourite 18Make Affine custom 166Map Grid 297

PropertiesGraphMap 361

propertiesimage 429legend 527, 530

Proximity Searchselecting objects based on distance from other

objects 201

QQuartic kernel function

density grid 599Querying


based on proximity to selected objects See Proximity Search

Querying tablessearching for particular text See Text Search

and Replace

Rradial search

in gridding 597range

inverse distance weighting 592kriging 589

Rank schemeGraphMap 409

rectangular regionclipping 688

rectifyimage 418image options XE 424image tool 420

reformat grids 688register the shade file 271Registered Raster 329

Convert Map 329Regression Line

GraphMap 390Relative path name 9Replace

GridUtility 708Text 111

Reproject 709reproject

coordinates 168image 426tables 131, 170

resamplegrids 712

resample grids 689resampling a grid 712Residuals Graph

GraphMap 390resource grid 540resource parameters

setup 542resources from cross-sections 540Restore

Mapper State 16

Restore Mapper State option 16RGB

formula 414grids 700

RGB Colourizer 272RGB values

GraphMap 414use in colour lookup tables See Colour Tables

roll-upof the ELC 179

Rose diagramGraphMap 374

Rotategrids 713GridUtility 713

rotateimage 435

rotate grids 689rotation

GraphMap 389rounded grid spacing 298Row Delimited 193

SSave

Filtered Grid 662Map Grids 300Mapper State 16

saveDrillhole Settings 564graoh data as MapInfo table 358graph data as CSV file 358graph legend as MapInfo table 358image control points 423

Save and Overlay Map Grids 300Save Mapper State tool 16Save Output Grid

GridUtility 694Save Plane 162Save tables to workspace folder 10Scale Factor 161scalebar

dynamic 23scalebar format 302scaled hardcopy output

configuring frame settings 286

Index 791

determining coverage 288hints 294scalebar format 302using an existing workspace as a template 304with standard map sheets 293

Scaled Output 283, 296Creating Additional 292Exit 295Hints 294Printing 292TitleBlock 290

Scaled Output button 284Scaled Output>Accept Map Position 290Scaled Output>Quit Scaled Output 295Scaled Output>ReSpecify Parameters 292Scaled Output>Respecify Parameters 289, 290Scaled Output>Restore Map Window 290, 293, 295

Scatter matrixGraphMap 373

Scatter plotGraphMap 371

SearchProimity 201Text 111

Search all holesrequired 540

search distanceGridding Tool 595

Search Distance controls 595search ellipse 544

in Grid Tool 544search expansions

Gridding Tool 595search orientation

for sectional resources 545Search tab

Gridding Tool 594Section

display options 478draw grid 537grid parameters 543horizontal plan 477layout options 535vertical 474

sectionmanager 493

section collar plancreate 538

section to layoutadd 533

Sectional Resource Calculator 540sections

Create Drillhole 440sector search ellipse 596SeeThru

Shading 321See-Thru Pattern Library 323See-Thru patterns 321See-Thru Shading

applying to selected regions 321SeeThru Shading 321

Create Pattern 322Density and Orientation 323Pattern Library 323Pattern Type 322

SEETHRU table 323Select

Group 112select

data columns 753Select All from Editable Layer 203Select by Graphical Styles 204Select by Group 112Select by Style dialog 204Select Object to Draw 196selection

image 419selection region

GraphMap 394Selection Statistics

GraphMap 405semivariance

kriging 588Send TitleBlock to Back checkbox 304Set Clip Region 294Set Default Table 15Set default table view

setting 15set point styles

output options 144Set Selection Overlay

GraphMap 390Settings


Grid Filter 664GridUtility 693

settingsglobal 523

Setup 349Frame 285

setupdrillhole project 450, 464, 469resource parameters 542

shade file (SHD) 270shade files 270Shade Quickview option 267Shading

See Thru 321Sharing workspaces 10Shift

grids 715GridUtility 715

sillkriging 589

simple krigingGridding Tool 590

Slopegrids 715GridUtility 715

smoothingin Grid Wizard 591

SortTables 114

Sort Table 114Spatial Neighbour

Gridding Tool 597Spatial Neighbour tab 597spatial neighbours

gridding 597Spatial view

gridding Statistics Explorer 617special symbol fonts 325specify

Azimuth method 753Specify Order option 309Specify the data value

of colours 650, 652spline interpolation

for contours 667Split

grids 717

GridUtility 717Split Multi-Polys 223splitting

multi-section polylines and regions 223spreadsheet

Gridding Tool 607Stacked Profile

Create 352standard

filters 657Standard Deviation

GraphMap 409Standard Map Sheets 293Standard Views 16statisics

Geochem 151statistics

GraphMap 405Statistics Explorer 578, 606

Gridding Tool 606Stereogram

GraphMap 374Store Resource in column 543stractureal

data options 752stream analysis 735, 745structural codes 753structural data

displaying as symbols See Structural Data Mapper

Structural Data Mapperdigitizing structural symbols 754Overview 749symbol codes 756

structural measurementsplotting See Stereogram

structural symbols 749, 750structure

symbols 749Structure Symbols

digitize 754structure symbols

create 750Style

Legend 310Style button

for legends 310Styles

Index 793

Library 305Styles Library 305

storing and applying standard object styles 305

SubsetDrillhole project 471

Sun Highlightgrids 653

sun illuminationGriddingTool 574

sun shadegrids 653

sun-angle filters 657sun-shading 652surface

geology 444grid and contour 444

Surface AnalysisProfile over a grid or contour plan 679

Surface curvature 701Surface menu 271Surface Profile See Surface Analysis 679Surfaces See gridsSurfer

grid import 89grid output 603

Surpac gridimport 87

Surpac stringexport 64import 62

survey tabledownload 442trench/costean 445

Symbol and Label Style 753symbol picker 749symbology

GraphMap 406symbols

structure 749

TTable

Multiple Utilities 129Set Default 15Split 117Transformation 159

tableappend 130, 131build colour 264collar 441comparison 131create look-up for grids 650download data 443download survey 442edit colour 265editing 131open 106pack 129reproject 131, 170structure 131

table of symbols 753Table Split 117Table Utilities

described 260, 417Table window

GraphMap 372table window

GraphMap 381Tables

absolute and relative path names 9Build Objects 192Columns 308Legend 308remove unused 9resolve missing 9save to workspace folder 10

tablessort 114

Tables and Columns 308taper

inverse distance weighting 594Temporal Trend View

Data Format 348Introduction 347

Temporal Trends 347Data Format 348Graph Colouring 352Graph Display 349Graph Query 352Setup 349

Tenements 759Ternary diagram

GraphMap 373


TextAdd Labels 313Additional Label Options 317Colour Labels from Pattern 318Format 315Label Expression 314Label Style 315Replace 111Search 111sizing for a given map scale 315

text angle 315Text Label Expression 314text label string into a column 318Text Label Style 315text labelling 313Text Labels 313Text Search and Replace 111

searching for and/or replacing particular text 111

Thematic 269, 270Auto-Shade 270Mapinfo 269

thematic map layercreate 267

Thematic map settingssaving and re-applying See Auto-Shade

ThinPolyline 213

Thin PolylineNode Number 213Node Position 214

Thin Polyline by Node Number 213Thin Polyline by Node Position 214Thin Polylines 213thinning polylines and regions

by node position 214Title Lines 303TITLEBLK.TAB 290, 304TitleBlock 290

Make Custom 301TitleBlock List 288Titleblock Position 304Titles 313

Layout Window frame 313tool dialog

image 428

Toolbars 2Tools

Distance and Bearing 21topographic elevation 567topographic grid

trench/costean 449Transform 158, 207

Coordinate 158Coordinates now 161Object 207

TransformationAffine 162Plane 160Save Plane 162Scale Factor 161Table 159

transformationMethods 425

Transformation Table 159transparency

grids 648Trench

creating view 487Drillholes 486

trenchannotation 490Bearing and Distance survey table 446collar table 444downhole data table 448plan creation 487section creation 488setup 465survey table 445topography grid 449XYZ survey table 445

Triangle kernel functiondensity grid 599

triangular irregular network 683Triangulation

Griddding Tool 598Triweight kernel function

density grid 599True Type Fonts

of structural symbols See Structural Data Mapper

TrueType font symbols 753TrueType symbol fonts 749

Index 795

tunnel wallcreating a section or plan 486

UUniform kernel function

density grid 599Univariate view

gridding Statistics Explorer 610unroll the ELC 179Update 318

Coordinates 157Table from Text Labels 318Text Labels from Table 318

Update Coordinatesstoring coordinates from multiple projections

158update coordinate columns from objects 158update object position from coordinate

columns 158update the text in text objects 318updating text labels 317Upper Tail scheme

GraphMap 409US structural symbols 752Use layer name aliases option 186Use nearest neighbours

Gridding Tool 596Use Other Files 271USGS DEM grid

import 91Utilities

Grid 688Multiple Table 129

Utils 661

Vvalidate

drillhole database 459Value parameter

GraphMap 380Values

Assign 224Constant 122Increment 122

Variogram viewgridding Statistics Explorer 619

Vector View 274Vectorize

grids 720GridUtility 720

VectorsPlot 274

version 2.1 gridconvert 94

Vertical Mapper 90toggle grid support 94

Vertical Mapper gridimport 90

vertical section 474viewing individual records

GraphMap 393viewing multiple records

GraphMap 381Views

Set Default Table 15Standard 16

Viewshedgrids 721GridUtility 721

Volulmegrids 724GridUtility 724

volumeof grids 686

Voronoi PolygonsCreate 683

Vulcan archiveexport 66import 65

Wwatershed 735weight model

inverse distance weighting 592weight power

in Grid Tool 544whiskers (box plot)

GraphMap 373Workspace

Editor 8make table path names absolute or relative 9packaging and sharing 10resolve missing tables 9


Workspace Editor 8Workspaces

Favourite 7Worspace

remove unused tables 9

XX axis asssignment

GraphMap 369XY point plot See Scatter plotXYZ

trench survey table 445

YY axis assignment

GraphMap 369

ZZ axis assignment

GraphMap 369Zoom to Extents of Selected Object 26zooming

GraphMap 389zooms

in GridProcessor 659

Discover User Guide

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