The QtiPlot Handbook i

The QtiPlot Handbook

The QtiPlot Handbook ii

Copyright © 2004 - 2018 Ion Vasilief

Copyright © 2010 Stephen Besch

Copyright © 2006 - june 2007 Roger Gadiou and Knut Franke

Legal notice: Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documen-tation License, Version 1.1 or any later version published by the Free Software Foundation; with no Invariant Sections, with noFront-Cover Texts, and with no Back-Cover Texts.

The QtiPlot Handbook iii

COLLABORATORS

TITLE :

The QtiPlot Handbook

ACTION NAME DATE SIGNATURE

WRITTEN BY Ion Vasilief The 1st of March 2018

REVISION HISTORY

NUMBER DATE DESCRIPTION NAME

The QtiPlot Handbook iv

Contents

1 Introduction 1

1.1 What QtiPlot does . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.2 Command Line Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.2.1 Specify a File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.2.2 Command Line Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1.3 General Concepts and Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1.3.1 Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

1.3.2 Excel workbooks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

1.3.3 Matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

1.3.4 Plot Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

1.3.5 Note . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

1.3.6 Results Log Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

1.3.7 The Project Explorer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

1.3.8 The Quick Help Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

1.3.9 The Scripting Console . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

1.4 Interoperability with other scientific software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

1.4.1 OriginLab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

1.4.1.1 Import of OriginLab projects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

1.4.1.2 Export QtiPlot projects to OriginLab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

1.4.2 Microsoft Excel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

1.4.2.1 Import of Excel files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

1.4.2.2 Export QtiPlot data to Excel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

1.4.3 LibreOffice and Apache OpenOffice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

1.4.3.1 Import . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

1.4.3.2 Export . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

The QtiPlot Handbook v

2 Drawing plots with QtiPlot 17

2.1 2D plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

2.1.1 2D plot from data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

2.1.2 2D plot from function. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

2.1.2.1 Direct plot of a function. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

2.1.2.2 Filling of a table with the values of a function. . . . . . . . . . . . . . . . . . . . . . . . . . . 21

2.2 3D plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

2.2.1 Direct 3D plot from a function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

2.2.2 3D plot from a matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

2.3 Multilayer Plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

2.3.1 Building a multilayer plot panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

2.3.2 Building a multilayer plot step by step . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

3 Command Reference 30

3.1 The File Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

3.1.1 File-> New -> . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

3.1.1.1 New -> New Project (Ctrl-N) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

3.1.1.2 New -> New Folder (F7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

3.1.1.3 New -> New Table (Ctrl-T) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

3.1.1.4 New -> New Excel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

3.1.1.5 New -> New Matrix (Ctrl-M) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

3.1.1.6 New -> New Note . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

3.1.1.7 New -> New Graph (Ctrl-G) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

3.1.1.8 New -> New Function Plot -> New Function Plot... (Ctrl-F) . . . . . . . . . . . . . . . . . . 32

3.1.1.9 New -> New Function Plot -> New Parametric Function Plot... . . . . . . . . . . . . . . . 33

3.1.1.10 New -> New Function Plot -> New 3D Surface Plot... (Ctrl-Alt-Z) . . . . . . . . . . . . . . 33

3.1.1.11 New -> New Function Plot -> New 3D Parametric Surface Plot... . . . . . . . . . . . . . . 33

3.1.2 File -> Open (Ctrl-O) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

3.1.3 File -> Open Excel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

3.1.4 File -> Open ODF Spreadsheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

3.1.5 File-> Open Image File (Ctrl-I) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

3.1.6 File -> Append Project... (Ctrl-Alt-A) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

3.1.7 File-> Recent Projects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

3.1.8 File -> Close . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

3.1.9 File-> Save Project (Ctrl-S) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

3.1.10 File-> Save Project as... (Ctrl-Shift-S) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

3.1.11 File-> Save Window as... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

3.1.12 File -> Open Template . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

3.1.13 File -> Save as Template . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

The QtiPlot Handbook vi

3.1.14 File-> Print (Ctrl-P) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

3.1.15 File-> Print Preview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

3.1.16 File-> Print All Plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

3.1.17 File -> Export Graph . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

3.1.17.1 Export Graph -> Current (Alt-G) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

3.1.17.2 Export Graph -> All (Alt-X) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

3.1.17.3 File -> Create Open Document Presentation... . . . . . . . . . . . . . . . . . . . . . . . . 36

3.1.18 File -> Export . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

3.1.18.1 Export ASCII . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

3.1.18.2 Export Excel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

3.1.18.3 Export to PDF (Ctrl-Alt-P) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

3.1.19 File -> Import . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

3.1.19.1 File -> Import -> Import ASCII... (Ctrl-K) . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

3.1.19.2 File-> Import Image... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

3.1.19.3 File -> Import -> Database... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

3.1.19.4 File -> Import -> Matlab... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

3.1.19.5 File -> Import -> Sound (WAV)... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

3.1.19.6 File -> Import -> NI (TDMS)... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

3.1.20 File -> Quit (Ctrl-Q) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

3.2 The Edit Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

3.2.1 Edit -> Undo (Ctrl-Z) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

3.2.2 Edit -> Redo (Ctrl-Shift-Z) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

3.2.3 Edit -> Cut Selection (Ctrl-X) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

3.2.4 Edit -> Copy Selection (Ctrl-C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

3.2.5 Edit -> Paste Selection (Ctrl-V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

3.2.6 Edit -> Delete Selection (Del) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

3.2.7 Edit -> Delete Fit Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

3.2.8 Edit -> Clear Log Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

3.2.9 Edit -> Preferences... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

3.3 The View Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

3.3.1 View -> Toolbars... (Ctrl-Shift-T) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

3.3.2 View -> Project Explorer (Ctrl-E) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

3.3.3 View -> Results log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

3.3.4 View -> Undo/Redo Stack... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

3.3.5 View -> Quick Help . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

3.3.6 View -> Console . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

3.4 The Scripting Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

3.4.1 General Scripting Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

3.4.1.1 Scripting -> Scripting language . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

The QtiPlot Handbook vii

3.4.1.2 Scripting -> Restart scripting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

3.4.1.3 Scripting -> Add Custom Script Action... . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

3.4.2 Notes Specific Scripting Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

3.4.2.1 Scripting -> Execute (Ctrl+J) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

3.4.2.2 Scripting -> Preferences... (Ctrl+Shift+J) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

3.4.2.3 Scripting -> Evaluate (Ctrl+Return) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

3.4.2.4 Rename Tab... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

3.4.2.5 Add Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

3.4.2.6 Close Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

3.5 The Graph Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

3.5.1 Graph -> Add/Remove Curves... (Alt-C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

3.5.2 Graph -> Add Function... (Ctrl-Alt-F) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

3.5.3 Graph -> Add Error Bars... (Ctrl-B) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

3.5.4 Graph -> Rescale To Show All (Ctrl-Shift-R) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

3.5.5 Graph -> Exchange X-Y Axes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

3.5.6 Graph -> New Legend (Ctrl-L) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

3.5.7 Graph -> Add Color Scale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

3.5.8 Graph -> Add Equation... (Alt-Q) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

3.5.9 Graph -> Add Text (Alt-T) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

3.5.10 Graph -> Draw Arrow (Ctrl-Alt-A) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

3.5.11 Graph -> Draw Line (Ctrl-Alt-L) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

3.5.12 Graph -> Add Rectangle (Ctrl-Alt-R) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

3.5.13 Graph -> Add Ellipse (Ctrl-Alt-E) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

3.5.14 Graph -> Add Time Stamp (Ctrl-Alt-T) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

3.5.15 Graph -> Add Image (Alt-I) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

3.5.16 Graph -> Add Central Axis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

3.5.16.1 Add Horizontal Axis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

3.5.16.2 Add Vertical Axis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

3.5.17 Z-Order Commands... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

3.5.17.1 Move to Top . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

3.5.17.2 Move to Bottom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

3.5.18 Graph -> Add Layer (Alt-L) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

3.5.19 Graph -> Add Empty Inset Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

3.5.20 Graph -> Add Inset Layer With Curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

3.5.21 Graph -> Arrange Layers... (Shift-A) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

3.5.22 Graph -> Automatic Layout command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

3.5.23 Graph -> Extract to Layers command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

3.5.24 Graph -> Extract to Graphs... command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

3.5.25 Graph -> Merge Graph Windows... command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

The QtiPlot Handbook viii

3.5.26 Graph -> Remove Layer (Alt-R) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

3.6 The Plot Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

3.6.1 Plot Wizard (Ctrl-Alt-W) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

3.6.2 Line -> . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

3.6.2.1 Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

3.6.2.2 Line Central . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

3.6.2.3 Vertical Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

3.6.2.4 Horizontal Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

3.6.3 Symbol -> . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

3.6.3.1 Scatter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

3.6.3.2 Scatter Central . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

3.6.3.3 Vertical Drop Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

3.6.3.4 Bubble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

3.6.3.5 Color Mapped . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

3.6.3.6 Bubble + Color Mapped . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

3.6.4 Line + Symbol -> . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

3.6.4.1 Line+Symbol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

3.6.4.2 Line + Symbol Central . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

3.6.4.3 Spline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

3.6.5 Column/Bar/Pie -> . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

3.6.5.1 Columns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

3.6.5.2 Rows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

3.6.5.3 Stack Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

3.6.5.4 Stack Bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

3.6.5.5 100% Stack Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

3.6.5.6 100% Stack Bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

3.6.5.7 Floating Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

3.6.5.8 Floating Bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

3.6.5.9 3D Color Pie Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

3.6.5.10 2D BW Pie Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

3.6.6 Multi-Curve -> . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

3.6.6.1 Double-Y . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

3.6.6.2 3Y: Y-YY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

3.6.6.3 4Y: YY-YY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

3.6.6.4 Stack Lines by Y Offsets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

3.6.6.5 Waterfall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

3.6.6.6 Colormapped Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

3.6.7 Area -> . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

3.6.7.1 Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

The QtiPlot Handbook ix

3.6.7.2 Stack Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

3.6.7.3 100% Stack Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

3.6.7.4 Fill Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

3.6.8 Special Line/Symbol -> . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

3.6.8.1 Vectors XYXY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

3.6.8.2 Vectors XYAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

3.6.8.3 Zoom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

3.6.9 Statistical Graphs -> . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

3.6.9.1 Box Plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

3.6.9.2 Histogram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

3.6.9.3 Histogram + Probabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

3.6.9.4 Stacked Histogram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

3.6.9.5 Stem and Leaf . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

3.6.10 Panel -> . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

3.6.10.1 Vertical 2 Layers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

3.6.10.2 Horizontal 2 Layers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

3.6.10.3 4 Layers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

3.6.10.4 Stacked Layers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

3.6.10.5 Custom Layout... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

3.6.11 Data -> Plot 3D -> . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

3.6.11.1 Ribbons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

3.6.11.2 Bars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

3.6.11.3 Scatter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

3.6.11.4 Trajectory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

3.7 The 3D Plot menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

3.7.1 3D Wire Frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

3.7.2 3D Hidden Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

3.7.3 3D Polygons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

3.7.4 3D Wire Surface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

3.7.5 Bars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

3.7.6 Scatter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

3.7.7 Contour+Color Fill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

3.7.8 Countour Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

3.7.9 Gray Scale Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

3.8 The Data Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

3.8.1 Data -> Disable tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

3.8.2 Data -> Zoom In/Out and Drag Canvas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

3.8.3 Data -> Zoom/Drag Canvas Horizontally . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

3.8.4 Data -> Zoom/Drag Canvas Vertically . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

The QtiPlot Handbook x

3.8.5 Data -> Zoom in (Ctrl-+) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

3.8.6 Data -> Zoom out (Ctrl--) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

3.8.7 Data -> Select Data Range (Alt-S) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

3.8.8 Data -> Data Reader (Ctrl-D) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

3.8.9 Data -> Annotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

3.8.10 Data -> Screen Reader . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

3.8.11 Data -> Draw Data Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

3.8.12 Data -> Move Data points (Ctrl-Alt-M) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

3.8.13 Data -> Remove Bad Data Points (Alt-B) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

3.8.14 Data -> Remove Bad Data Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

3.9 The Analysis Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

3.9.1 Commands for the analysis of data in tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

3.9.1.1 Descriptive Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

3.9.1.1.1 Statistics on Columns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

3.9.1.1.2 Statistics on Rows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

3.9.1.1.3 Frequency Count . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

3.9.1.1.4 Normality Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

3.9.1.2 Hypothesis-Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

3.9.1.2.1 One Sample t-Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

3.9.1.2.2 Two Sample t-Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

3.9.1.3 ANOVA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

3.9.1.3.1 One-Way ANOVA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

3.9.1.3.2 Two-Way ANOVA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

3.9.1.4 Sort Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

3.9.1.4.1 Ascending . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

3.9.1.4.2 Descending . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

3.9.1.4.3 Custom... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

3.9.1.5 Sort Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

3.9.1.6 Normalize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

3.9.1.6.1 Normalize -> Columns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

3.9.1.6.2 Normalize -> Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

3.9.1.7 Differentiate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

3.9.1.8 Integrate... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

3.9.1.9 FFT... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

3.9.1.10 Correlate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

3.9.1.11 Autocorrelate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

3.9.1.12 Convolute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

3.9.1.13 Deconvolute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

3.9.1.14 Fit Wizard... (Ctrl-Y) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

The QtiPlot Handbook xi

3.9.2 Commands for the analysis of curves in plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

3.9.2.1 Translate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

3.9.2.1.1 Vertical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

3.9.2.1.2 Horizontal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

3.9.2.2 Subtract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

3.9.2.2.1 Subtract -> Baseline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

3.9.2.2.2 Subtract -> Reference Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

3.9.2.2.3 Subtract -> Straight Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

3.9.2.3 Peaks... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

3.9.2.4 Differentiate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

3.9.2.5 Integrate... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

3.9.2.6 Integrate Function... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

3.9.2.7 Smooth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

3.9.2.7.1 Savitski-Golay... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

3.9.2.7.2 Moving Window Average... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

3.9.2.7.3 Lowess... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

3.9.2.7.4 FFT Filter... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

3.9.2.8 FFT Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

3.9.2.8.1 Low Pass... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

3.9.2.8.2 High Pass... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

3.9.2.8.3 Band Pass... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

3.9.2.8.4 Band Block... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

3.9.2.9 Interpolate... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

3.9.2.10 FFT... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

3.9.2.11 Fit Linear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

3.9.2.12 Fit Polynomial... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

3.9.2.13 Fit Exponential Decay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

3.9.2.13.1 First Order... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

3.9.2.13.2 Second Order... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

3.9.2.13.3 Third Order... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

3.9.2.14 Fit Exponential Growth... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

3.9.2.15 Fit Boltzmann (sigmoidal) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

3.9.2.16 Fit Pseudo-Voigt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

3.9.2.16.1 PsdVoigt1... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

3.9.2.16.2 PsdVoigt2... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

3.9.2.17 Fit Gaussian . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

3.9.2.18 Fit Lorentzian . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

3.9.2.19 Fit Multi-peak . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

3.9.2.19.1 Gaussian... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

The QtiPlot Handbook xii

3.9.2.19.2 Lorentzian... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

3.9.2.19.3 PsdVoigt1... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

3.9.2.19.4 PsdVoigt2... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

3.9.3 Commands for the analysis of data in matrices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

3.9.3.1 Integrate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

3.9.3.2 FFT... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

3.9.3.3 Forward FFT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

3.9.3.4 Inverse FFT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

3.9.3.5 FFT Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

3.9.3.5.1 Low Pass... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

3.9.3.5.2 High Pass... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

3.9.3.5.3 Band Pass... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

3.9.3.5.4 Band Block... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

3.10 The Table Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

3.10.1 Set Column As . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

3.10.1.1 Set Column As -> X . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

3.10.1.2 Set Column As -> Y . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

3.10.1.3 Set Column As -> Z . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

3.10.1.4 Set Column As -> X error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

3.10.1.5 Set Column As -> Y error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

3.10.1.6 Set Column As -> Read-only . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

3.10.1.7 Set Column As -> Read/Write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

3.10.1.8 Set Column As -> label . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

3.10.1.9 Set Column As -> Disregard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

3.10.2 Column Options... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

3.10.3 Set Column Values... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

3.10.4 Recalculate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

3.10.5 Fill column with . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

3.10.5.1 Fill Column With -> Row Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

3.10.5.2 Fill Column With -> Random Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

3.10.5.3 Fill Column With -> Normal Random Numbers . . . . . . . . . . . . . . . . . . . . . . . . 82

3.10.6 Clear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

3.10.7 Add Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

3.10.8 Set Columns... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

3.10.9 Hide Selected Columns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

3.10.10 Show All Columns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

3.10.11 Alignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

3.10.11.1 Alignment -> Left . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

3.10.11.2 Alignment -> Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

The QtiPlot Handbook xiii

3.10.11.3 Alignment -> Right . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

3.10.12 Adjust Column Width . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

3.10.13 Move to First . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

3.10.14 Move Left . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

3.10.15 Move Right . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

3.10.16 Move to Last . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

3.10.17 Swap columns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

3.10.18 Set Rows... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

3.10.19 Delete Rows Interval... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

3.10.20 Move Row . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

3.10.20.1 Move Row -> UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

3.10.20.2 Move Row -> DOWN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

3.10.21 Go to Row... (Ctrl-Alt-G) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

3.10.22 Go to Column... (Ctrl-Alt-C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

3.10.23 Extract Data... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

3.10.24 Convert to Matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

3.10.24.1 Convert to Matrix -> Direct . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

3.10.24.2 Convert to Matrix -> 2D Binning... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

3.10.24.3 Convert to Matrix -> Regular XYZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

3.10.24.4 Convert to Matrix -> Random XYZ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

3.11 The Matrix Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

3.11.1 Set Properties... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

3.11.2 Set Dimensions... (Ctrl-D) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

3.11.3 Set Values... (Ctrl-Q) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

3.11.4 Recalculate (Ctrl-Return) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

3.11.5 Rotate 90 (Ctrl-Shift-R) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

3.11.6 Rotate -90 (Ctrl-Alt-R) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

3.11.7 Flip V (Ctrl-Shift-V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

3.11.8 Flip H (Ctrl-Shift-H) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

3.11.9 Expand... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

3.11.10 Shrink... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

3.11.11 Smooth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

3.11.12 Transpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

3.11.13 Invert . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

3.11.14 Determinant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

3.11.15 Go To Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

3.11.16 View Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

3.11.16.1 Image mode (Ctrl-Shift-I) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

3.11.16.2 Data mode (Ctrl-Shift-D) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

The QtiPlot Handbook xiv

3.11.17 Palette . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

3.11.17.1 Gray Scale Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

3.11.17.2 Rainbow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

3.11.17.3 Custom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

3.11.18 Show Column/Row (Ctrl-Shift-C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

3.11.19 Show X/Y (Ctrl-Shift-X) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

3.11.20 Convert to Spreadsheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

3.12 The Format Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

3.12.1 Apply Template... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

3.12.2 Edit Range... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

3.12.3 Plot Associations... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

3.12.4 Plot... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

3.12.5 Curves... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

3.12.6 Scales... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

3.12.7 Axes... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

3.12.8 Grid... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

3.12.9 Title... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

3.13 The Windows Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

3.13.1 Folders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

3.13.2 Cascade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

3.13.3 Tile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

3.13.4 Next (F5) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

3.13.5 Previous (F6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

3.13.6 Find... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

3.13.7 Rename Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

3.13.8 Duplicate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

3.13.9 Script Window (F3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

3.13.10 Window Geometry... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

3.13.11 Hide Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

3.13.12 Close Window (Ctrl-W) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

3.13.13 Numbered Window List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

3.14 Customization of 3D plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

3.14.1 Frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

3.14.2 Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

3.14.3 No axes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

3.14.4 Front Grid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

3.14.5 Back Grid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

3.14.6 Left Grid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

3.14.7 Right Grid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

The QtiPlot Handbook xv

3.14.8 Ceiling Grid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

3.14.9 Floor Grid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

3.14.10 Enable perspective . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

3.14.11 Reset rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

3.14.12 Fit frame to window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

3.14.13 Bars Style . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

3.14.14 Dots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

3.14.15 Cones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

3.14.16 Cross Hairs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

3.14.17 3D Wire Frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

3.14.18 3D Hidden Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

3.14.19 3D Polygons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

3.14.20 3D Wire Surface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

3.14.21 Floor Data Projection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

3.14.22 Floor Isolines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

3.14.23 Empty Floor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

3.14.24 Animation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

4 The Toolbars 94

4.1 The Edit Toolbar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94

4.2 The File Toolbar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94

4.3 The Plot Toolbar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

4.4 The Layers Toolbar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

4.5 The Table Toolbar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

4.6 The Column Toolbar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

4.7 The Plot 3D Toolbar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

5 The Dialogs 104

5.1 Window Properties Dialog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104

5.2 Add Custom Action . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104

5.3 Custom Color Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

5.4 Add Error bars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107

5.5 Function Dialog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

5.6 Add Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

5.7 Add/Remove Curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

5.8 Arrange Layers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112

5.9 Graph Manipulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114

5.10 Line Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115

5.10.1 Line Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115

The QtiPlot Handbook xvi

5.10.2 Arrow Head Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

5.10.3 Geometry Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

5.10.4 Axes Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

5.11 Column Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

5.12 Plot Associations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118

5.13 Edit Curve Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119

5.14 Plot Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119

5.14.1 Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

5.14.2 Print . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

5.14.3 Fonts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

5.14.4 Miscellaneous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

5.14.5 Window Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122

5.14.6 Legends/Titles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122

5.14.7 Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123

5.14.8 Canvas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124

5.14.9 Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125

5.14.10 Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125

5.14.11 Layer Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

5.14.12 Stack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127

5.14.13 Group Edit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128

5.14.14 Curve axes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129

5.14.15 Line/Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130

5.14.16 Symbol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130

5.14.17 Labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132

5.14.18 Offset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133

5.14.19 Error bars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133

5.14.20 Pie plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134

5.14.21 Pie geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135

5.14.22 Pie labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136

5.14.23 Box/Whiskers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136

5.14.24 Percentile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137

5.14.25 Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137

5.14.26 Spacing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138

5.14.27 Histogram Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138

5.14.28 Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139

5.14.29 Vector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140

5.14.30 Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142

5.14.31 Colors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143

5.14.32 Contour Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145

The QtiPlot Handbook xvii

5.14.33 Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147

5.15 Define surface plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148

5.16 Export Graph Dialog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150

5.17 Fast Fourier Transform Dialog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153

5.18 FFT Filter Dialog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155

5.19 Find Peaks Dialog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157

5.20 Frequency Count Dialog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158

5.21 Baseline Dialog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158

5.22 Integration Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159

5.23 Integrate Function Dialog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160

5.24 Polynomial Fit Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161

5.25 The Fit Wizard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162

5.25.1 Select Function Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162

5.25.2 Fitting Session Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163

5.25.3 Custom Output Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165

5.25.3.1 Reported errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166

5.25.3.2 Goodness-of-Fit Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166

5.26 General Plot Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167

5.26.1 Scale Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167

5.26.2 Grid Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167

5.26.3 Axis Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168

5.26.4 Special Ticks Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169

5.26.5 General Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170

5.27 The Plot Wizard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171

5.28 Project Explorer Find Dialog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172

5.29 Preferences Dialog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173

5.29.1 General Preferences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173

5.29.1.1 Application Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174

5.29.1.2 Confirmations Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175

5.29.1.3 Colors Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176

5.29.1.4 Numeric Format Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177

5.29.1.5 File Locations Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178

5.29.1.6 Keyboard Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179

5.29.1.7 Internet Connections Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180

5.29.2 Tables Preferences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181

5.29.3 2D Plot Preferences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182

5.29.3.1 Options Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182

5.29.3.2 Curves Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183

5.29.3.3 Error Bars Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184

The QtiPlot Handbook xviii

5.29.3.4 Axes Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185

5.29.3.5 Ticks Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186

5.29.3.6 Grid Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187

5.29.3.7 Geometry Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188

5.29.3.8 Speed Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189

5.29.3.9 Fonts Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190

5.29.3.10 Print Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191

5.29.4 3D Plot Preferences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192

5.29.5 Notes Preferences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193

5.29.6 Fitting Preferences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194

5.30 Printer-setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196

5.31 Set Column Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197

5.32 Extract Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198

5.33 Set Matrix Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199

5.34 Matrix Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200

5.35 Set Matrix Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200

5.36 Bin Matrix Dialog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201

5.37 Random XYZ Gridding Dialog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202

5.38 Surface plot options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204

5.38.1 Scale Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204

5.38.2 Axis Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205

5.38.3 Grid Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206

5.38.4 Title Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206

5.38.5 Data Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207

5.38.6 Colors Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207

5.38.7 3D Vectors Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208

5.38.8 Legend Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208

5.38.9 General Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209

5.38.10 Print Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210

5.39 Sorting Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211

5.40 Tex Equation Editor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211

5.41 Text options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213

5.42 Export ASCII Dialog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217

5.43 Import ASCII files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218

5.44 Import database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220

5.45 Open TDMS File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221

The QtiPlot Handbook xix

6 Analysis of data and curves 224

6.1 Fast Fourier Transform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224

6.2 Correlation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225

6.3 Convolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226

6.4 Deconvolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226

6.5 The Fit Wizard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226

6.6 Fitting to specific curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227

6.6.1 Fitting to a line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227

6.6.2 Fitting to a polynomial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228

6.6.3 Fitting to a Boltzmann function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229

6.6.4 Fitting to a Gauss function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230

6.6.5 Fitting to a Lorentz function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231

6.6.6 Fitting to a PsdVoigt1 function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232

6.6.7 Fitting to a PsdVoigt2 function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232

6.7 Multi-Peaks fitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233

6.8 Filtering of data curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233

6.8.1 FFT low pass filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234

6.8.2 FFT high pass filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235

6.8.3 FFT band pass filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236

6.8.4 FFT block band filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237

6.9 Interpolation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238

7 Mathematical Expressions and Scripting 240

7.1 muParser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240

7.2 Python . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240

7.2.1 The Initialization File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240

7.2.2 Python Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241

7.2.3 Defining Functions and Control Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243

7.2.4 Mathematical Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244

7.2.5 Accessing QtiPlot’s objects from Python . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244

7.2.6 User settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248

7.2.7 Project Folders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248

7.2.8 Working with Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249

7.2.8.1 Columns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255

7.2.8.2 Statistics on columns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257

7.2.8.3 Data searching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257

7.2.8.4 Data mask . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258

7.2.8.5 Import ASCII files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258

7.2.8.6 Importing Excel sheets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259

The QtiPlot Handbook xx

7.2.8.7 Importing ODF spreadsheets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259

7.2.8.8 Export Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259

7.2.8.9 R interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260

7.2.9 Working with Matrices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260

7.2.10 Table/Matrix conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263

7.2.11 Stem Plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264

7.2.12 2D Plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264

7.2.12.1 The plot title . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265

7.2.12.2 Customizing the axes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265

7.2.12.3 The canvas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268

7.2.12.4 The layer frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269

7.2.12.5 Customizing the grid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269

7.2.12.6 The plot legend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269

7.2.12.7 Antialiasing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271

7.2.12.8 Resizing layers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271

7.2.12.9 Resizing the drawing area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271

7.2.12.10 Working with 2D curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272

7.2.12.11 Curve baseline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276

7.2.12.12 Curve values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276

7.2.12.13 Curve symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277

7.2.12.14 Curve labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280

7.2.12.15 Curve drop shadow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281

7.2.12.16 Selecting a data range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281

7.2.12.17 2D Analytical Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282

7.2.12.18 Error Bars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283

7.2.12.19 Image and Contour Line Plots (Spectrograms) . . . . . . . . . . . . . . . . . . . . . . . . . . 283

7.2.12.20 Histograms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284

7.2.12.21 Box and whiskers plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285

7.2.12.22 Distribution Curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286

7.2.12.23 Pie Plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287

7.2.12.24 Vector Plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287

7.2.12.25 Adding arrows/lines to a plot layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288

7.2.12.26 Adding images to a layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289

7.2.12.27 Rectangles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289

7.2.12.28 Circles/Ellipses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290

7.2.12.29 Color Scale Legends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290

7.2.12.30 Exporting graphs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293

7.2.12.31 Arranging Layers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294

7.2.12.32 Waterfall Plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295

The QtiPlot Handbook xxi

7.2.13 3D Plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296

7.2.13.1 Creating a 3D plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296

7.2.13.2 Customizing the view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297

7.2.13.3 Plot Styles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297

7.2.13.4 3D Vectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 298

7.2.13.5 The 2D Projection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299

7.2.13.6 The Coordinates System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299

7.2.13.7 Grid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299

7.2.13.8 Customizing the Plot Colors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300

7.2.13.9 Exporting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300

7.2.14 Data Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301

7.2.14.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301

7.2.14.2 Analysis Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302

7.2.14.3 Correlation, Convolution/Deconvolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304

7.2.14.4 Differentiation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304

7.2.14.5 FFT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304

7.2.14.6 FFT Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305

7.2.14.7 Fitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 306

7.2.14.8 Integration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309

7.2.14.9 Interpolation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309

7.2.14.10 Smoothing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310

7.2.14.11 Find Peaks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310

7.2.15 Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311

7.2.15.1 Descriptive Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311

7.2.15.2 Hypothesis Testing - Student’s t-Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311

7.2.15.3 One Sample Test for Variance (Chi-Square Test) . . . . . . . . . . . . . . . . . . . . . . . . . 311

7.2.15.4 Normality Test (Shapiro - Wilk) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312

7.2.15.5 One-Way ANOVA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312

7.2.15.6 Two-Way ANOVA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312

7.2.16 Working with Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313

7.2.17 Using PyQt’s dialogs and classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313

7.2.18 Using Qt Designer for easy creation of custom user dialogs . . . . . . . . . . . . . . . . . . . . . . . . . 314

7.2.19 Task automation example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314

7.2.20 Scope Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 316

7.2.21 QtiPlot/Python API . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317

7.2.22 PyQt Class Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317

8 Frequently asked questions 318

9 Index 319

The QtiPlot Handbook xxii

List of Figures

1.1 A typical QtiPlot session . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.2 The QtiPlot table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

1.3 Working with Excel workbooks in QtiPlot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

1.4 Context menu for Excel workbooks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

1.5 Properties dialog for Excel workbooks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

1.6 The QtiPlot matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

1.7 An example of QtiPlot 2D graph . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

1.8 The QtiPlot Note Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

1.9 The QtiPlot Results Log window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

1.10 The QtiPlot Project Explorer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

1.11 The Quick Help Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

1.12 The Scripting Console . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

1.13 Export QtiPlot windows/projects as Origin C files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

1.14 OriginLab - Create new custom menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

1.15 OriginLab - New custom menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

1.16 OriginLab - New custom menu item . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

1.17 OriginLab - Import script . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

1.18 OriginLab - Select C file generated by QtiPlot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

2.1 A simple 2D plot: the table. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

2.2 A simple 2D plot: the default plot. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

2.3 A simple 2D plot: the plot finished. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

2.4 A 2D plot with two Y axes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

2.5 Direct plot of a function. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

2.6 Function plot: filling of the X column. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

2.7 Function plot: filling of the Y column. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

2.8 Example of a 3D Plots. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

2.9 Definition of a new surface 3D plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

2.10 The 3D surface plot created using defaults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

2.11 The 3D surface plot after customization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

The QtiPlot Handbook xxiii

3.1 The Smooth -> Savitsky-Golay... dialog. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

3.2 The Smooth -> Moving Window Average... dialog. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

3.3 The Smooth -> Lowess... dialog. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

3.4 The Smooth -> FFT Filter... dialog. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

3.5 The FFT Filter -> Low Pass... dialog. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

3.6 The FFT Filter -> High Pass... dialog. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

3.7 The FFT Filter -> Band Pass... dialog. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

3.8 The FFT Filter -> Band Block... dialog. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

3.9 The Interpolate... dialog. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

4.1 The QtiPlot Edit Toolbar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94

4.2 The QtiPlot File Toolbar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94

4.3 The QtiPlot Plot Toolbar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

4.4 The QtiPlot Layers Toolbar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

4.5 The QtiPlot Table Toolbar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

4.6 The QtiPlot Column Toolbar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

4.7 The QtiPlot Plot 3D Toolbar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

5.1 The Rename Window dialog box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104

5.2 The Add Custom Script Action... dialog box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

5.3 The Custom Color Map dialog box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

5.4 Set Equidistant Levels dialog box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

5.5 The Two Colors mode of the Gradient Fill dialog box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

5.6 The Custom Color Map mode of the Gradient Fill dialog box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107

5.7 The Error bars dialog. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107

5.8 Example of a plot with both X and Y Error Bars. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

5.9 The Add Function... dialog box: Cartesian Coordinates. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109

5.10 The Add Function... Dialog Box: Automatic Detection of Constants. . . . . . . . . . . . . . . . . . . . . . . . 110

5.11 The Add Function... dialog box: Parametric Coordinates. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110

5.12 The Add Function... dialog box: Polar Coordinates. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

5.13 The Add Layer Dialog Box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

5.14 The Add/Remove Curves... Dialog Box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112

5.15 The Arrange Layers... dialog: the Geometry Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

5.16 Example of a vertical arrangement for two plots. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114

5.17 The Graph Manipulation dialog used for extracting individual layers from 2D graph windows. . . . . . . . . . . 114

5.18 The Graph Manipulation dialog used for merging 2D graph windows. . . . . . . . . . . . . . . . . . . . . . . . 115

5.19 The Arrow Options Dialog: Line Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

5.20 The Arrow Options Dialog: Arrow Head Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

5.21 The Arrow Options Dialog: Geometry Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

The QtiPlot Handbook xxiv

5.22 The Arrow Options Dialog: Axes Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

5.23 The Column Options... Dialog. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118

5.24 The Plot Associations Dialog. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119

5.25 The Edit Curve Range Dialog. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119

5.26 The Plot Details Dialog: Dimensions tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

5.27 The Plot Details Dialog: Print tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

5.28 The Plot Details Dialog: Fonts tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

5.29 The Plot Details Dialog: Miscellaneous tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122

5.30 The Plot Details Dialog: Display tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122

5.31 The Plot Details Dialog: Legends/Titles tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123

5.32 The Plot Details Dialog: Layer properties. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124

5.33 The Plot Details Dialog: Canvas with a solid background color. . . . . . . . . . . . . . . . . . . . . . . . . . . . 124

5.34 The Plot Details Dialog: Canvas with a background image. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125

5.35 The Plot Details Dialog: Canvas geometry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125

5.36 The Plot Details Dialog: Layer Speed Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

5.37 The Plot Details Dialog: Layer Display. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127

5.38 The Plot Details Dialog: Layer Display. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128

5.39 The Plot Details Dialog: Group Edit tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128

5.40 Context menu of a plot layer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129

5.41 The Plot Details Dialog: Assign Axes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130

5.42 The Plot Details Dialog: Line formatting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130

5.43 The Plot Details Dialog: Standard Symbol formatting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131

5.44 The Plot Details Dialog: Unicode Symbol formatting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132

5.45 The Plot Details Dialog: Image Symbol formatting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132

5.46 The Plot Details Dialog: Labels formatting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133

5.47 The Plot Details Dialog: Offset formatting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133

5.48 The Plot Details Dialog for formatting error bars. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134

5.49 The Plot Details Dialog for pies: Pie Segment Formatting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135

5.50 The Plot Details Dialog for pies: Pie Geometry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135

5.51 The Plot Details Dialog for pies: Pie Labels Formatting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136

5.52 The Plot Details Dialog for box: Whiskers Formatting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136

5.53 The Plot Details Dialog for box: Percentile Formatting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137

5.54 The Plot Details Dialog for box: Data Formatting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138

5.55 The Plot Details Dialog for histograms: Spacing Formatting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138

5.56 The Plot Details Dialog for histograms: Data Formatting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139

5.57 The Plot Details Dialog: Distribution Curve Line formatting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140

5.58 The Plot Details Dialog for Vector XYXY curves. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141

5.59 The Plot Details Dialog for Vector XYAM curves. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141

5.60 The Values tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142

The QtiPlot Handbook xxv

5.61 The Colors tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143

5.62 Set Equidistant Levels dialog box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144

5.63 The Two Colors mode of the Gradient Fill dialog box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144

5.64 The Custom Color Map mode of the Gradient Fill dialog box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144

5.65 The Contour Lines tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146

5.66 The Labels tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146

5.67 The Plot Details Dialog for curve analysis operations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147

5.68 Context menu for a Lorentz data fit analysis operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148

5.69 The New -> New Function Plot -> New 3D Surface Plot... dialog box. . . . . . . . . . . . . . . . . . . . . . . 149

5.70 The New -> New Function Plot -> New 3D Surface Plot... dialog box. . . . . . . . . . . . . . . . . . . . . . . 150

5.71 The FFT... dialog box for a curve. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153

5.72 The FFT... dialog box for a table. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154

5.73 The FFT... dialog box for a matrix. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154

5.74 The FFT Filter -> Low Pass... dialog. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155

5.75 The FFT Filter -> High Pass... dialog. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155

5.76 The FFT Filter -> Band Pass... dialog. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156

5.77 The FFT Filter -> Band Block... dialog. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156

5.78 The FFT Filter Dialog dialog box for a matrix. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156

5.79 The Find Peaks dialog box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157

5.80 The Frequency Count dialog. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158

5.81 The Baseline dialog. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158

5.82 The Integration Options dialog box for curves. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159

5.83 The Integration Options dialog box for tables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160

5.84 The Integrate Function... dialog box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161

5.85 The Polynomial Fit Options dialog box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162

5.86 The first step of the Fit Wizard... dialog box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163

5.87 The second step of the Fit Wizard... dialog box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164

5.88 The third step of the Fit Wizard... dialog box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165

5.89 General plot options dialog: The Scale Tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167

5.90 General plot options dialog: The Grid Tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168

5.91 General plot options dialog: The Axis Tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169

5.92 General plot options dialog: The Special Ticks Tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170

5.93 General plot options dialog: General Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171

5.94 The plot wizard dialog box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172

5.95 The project explorer find dialog. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172

5.96 The preferences dialog: general parameters for the application. . . . . . . . . . . . . . . . . . . . . . . . . . . . 174

5.97 The Preferences dialog: Confirmations tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176

5.98 The Preferences dialog: Colors tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177

5.99 The Preferences dialog: Numeric Format tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178

The QtiPlot Handbook xxvi

5.100The preferences dialog: File Locations Tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179

5.101The preferences dialog: Keyboard Tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180

5.102The preferences dialog: Internet Connection Tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181

5.103The Preferences dialog: table options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182

5.104The preferences dialog: 2D plot options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183

5.105The Preferences dialog: Curves Tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184

5.106The Preferences dialog: Error Bars Tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185

5.107The Preferences dialog: Axes Tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186

5.108The Preferences dialog: Ticks Tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187

5.109The Preferences dialog: Grid Tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188

5.110The Preferences dialog: Geometry Tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189

5.111The Preferences dialog: Speed Tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190

5.112The Preferences dialog: Fonts Tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191

5.113The Preferences dialog: Print Tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192

5.114The preferences dialog: 3D plot options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193

5.115The preferences dialog: note options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194

5.116The preferences dialog: fitting options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195

5.117The Print dialog. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197

5.118The Set Column Values... dialog. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198

5.119The Extract Data... dialog. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199

5.120The Set Dimensions... dialog for matrix. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200

5.121The Set Properties... dialog for matrices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200

5.122The Set Values... dialog for matrix. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201

5.123The Bin Matrix Dialog dialog box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201

5.124Scatter plot showing the number the data points falling within each 2D bin. . . . . . . . . . . . . . . . . . . . . 202

5.125The Shepard’s interpolation method. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203

5.126The Random XYZ Gridding dialog box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204

5.127The surface plot options dialog box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205

5.128The 3D Vector options tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208

5.129The legend tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209

5.130The general plot options tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210

5.131The 3D plot print options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210

5.132The Sorting Options Dialog. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211

5.133The Tex Equation Editor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211

5.134The Tex Equation Editor: compilation of complete LaTeX documents. . . . . . . . . . . . . . . . . . . . . . . . 213

5.135The axis title options dialog. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214

5.136The legend/text options dialog. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215

5.137Export of a selection from a table to an ASCII file. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218

5.138The dialog box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219

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5.139SQL database table/view selection with query dialog. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221

5.140Database table/view selection dialog on Linux and macOS systems. . . . . . . . . . . . . . . . . . . . . . . . . 221

5.141The Open TDMS File dialog box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222

5.142The TDMS channel properties dialog. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223

6.1 An example of the FFT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224

6.2 An example of a correlation between two sine functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226

6.3 The results of the Fit Wizard.... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227

6.4 The results of a Fit Linear. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228

6.5 The results of a Fit Polynomial..., showing the initial data, the curve added to the plot, and the results in the logpanel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229

6.6 The results of a Fit Boltzmann (sigmoidal). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230

6.7 The results of a Fit Gaussian. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231

6.8 The results of a Fit Lorentzian. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232

6.9 The results of a Fit Multi-peak -> Gaussian.... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233

6.10 Signal after a FFT low pass filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234

6.11 Signal after a FFT high pass filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235

6.12 Signal after a FFT band pass filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236

6.13 Signal after a FFT block band filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237

6.14 Comparison of the three methods of interpolation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239

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List of Tables

4.1 Edit toolbar commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

4.2 File toolbar commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

4.3 New Window/Folder Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

4.4 New Function/Surface Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

4.5 Open Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

4.6 Plot toolbar commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

4.7 Plot Toolbar Zoom Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

4.8 Read Data Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

4.9 Edit Data Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

4.10 Add Text Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

4.11 Add Line/Arrow Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

4.12 Geometric Shape Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

4.13 Z-order Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

4.14 Align Objects Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

4.15 Layers toolbar commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

4.16 Add Layer/Axes Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

4.17 Table toolbar commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

4.18 Line Plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

4.19 Scatter Plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

4.20 Line & Symbol Plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

4.21 Bar Chart Plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

4.22 Statistical Plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

4.23 Vector Plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

4.24 Special Line/Symbol Plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

4.25 3D Plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

4.26 Column toolbar commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

4.27 3D Plot toolbar commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

7.1 muParser: Predefined Fundamental Physical Constants in the standard MKSA unit system . . . . . . . . . . . . 240

7.2 muParser: Supported Mathematical Operators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241

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7.3 muParser: Mathematical Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242

7.4 muParser: Other functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243

7.5 Python: Supported Mathematical Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245

Abstract

This document is a handbook for using QtiPlot, a program for two- and three-dimensional graphical presentation of data sets andfor data analysis.

This manual is organized in several chapters:

-The first chapter describes the main concepts and terms which are used in QtiPlot.

-The second chapter is a tutorial on how to obtain plots from different data sets. It is the one you need to read first to understandthe basics of QtiPlot and to be able to draw plots.

-The three following chapters are descriptions of all the commands, buttons and dialogs used in QtiPlot. These chapters are thereference manual of QtiPlot.

- The two following chapters describe more deeply some specific possibilities of QtiPlot, that is the statistical and mathematicalanalysis of data, and the scripting.

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Chapter 1

Introduction

1.1 What QtiPlot does

QtiPlot is a program for two- and three-dimensional graphical presentation of data sets and for data analysis. Plots can beproduced from data sets stored in tables or from analytical functions.

QtiPlot is a dynamic tool: Plots created from data sets, and the tables owning that data, are interconnected. When any table ismodified, all objects in dependent plots (curves, axes scales, legends) are automatically updated. For example, deleting a table,or perhaps only some of the columns, will automatically remove all the corresponding curves from dependent plots. Plots can beexported in several graphic formats (eg: jpeg, png, bmp, pdf, etc) and inserted as images in documents or presentations.

All settings for a complete set of tables, matrices and plots can be saved in a project file having the extension ".qti". These projectfiles may be opened using the command line, the File menu, or by using the Open project icon from the File toolbar.

Data analysis operations (integration, interpolation, FFT, curve fitting, etc.) can be performed on the curves in a 2D plot via theAnalysis menu. The results of all these operations are also stored in the project file. They can be visualized at any time using theResults log and can be deleted from the project file via the Clear Log Information command.

When the application is launched, a new untitled project file is created consisting of a grey main window (the workspace) whichmay initially contain an empty child window, depending on your preferences. The type of this initial child window can becustomized using the Preferences dialog. It may be a table, a matrix, a note or an empty 2D graph window. In order to beoperational, the workspace must be populated with at least one data container. Either empty tables or matrices may be createdmanually (New Table command) and then filled with data, or they may created by importing ASCII files (Import -> ImportASCII... command), which automatically creates new tables.

The user can easily navigate through the objects of a project file by using either the project explorer or the Windows menu. Theproject explorer also allows the user to perform various operations on the windows (tables and plots) in the workspace: hiding,minimizing, closing, renaming, printing, etc.

1.2 Command Line Parameters

1.2.1 Specify a File

When starting QtiPlot from the command prompt, you can supply the name of a project file:

qtiplot file_name.qti

Other file formats are also accepted: .opj, .ogm, .ogw, .ogg for Origin projects, .qti, qti.gz for QtiPlot projects, .xls, .xlsx for Excelworkbooks, .ods, .fods for Open Document Format Spreadsheets, .mat for Matlab files, .tdms for LabVIEW TDM Streaming(TDMS) file format, .db, .dbf, .mdb, .accdb for dBase, MySQL, SQLite and Microsoft Access databases and all the image fileformats (raster or vectorial) that can be read by QtiPlot.

The name can also refer to an ASCII file:

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qtiplot ASCII_file_name

In this latter case, a new "untitled" project will be created, containing a table or matrix with the ASCII data from the file. The fileis read and interpreted using the current settings from the Import -> Import ASCII... command dialog.

1.2.2 Command Line Options

Valid options are:

• -a or --about: show about dialog and exit

• -c or --console: show standalone scripting window

• -d or --default-settings: start QtiPlot with the default settings

• -h or --help: show command line options

• -l=XX or --lang=XX: start QtiPlot in language XX (’en’, ’fr’, ’de’, ...)

• -m or --manual: show QtiPlot manual in a standalone window

• -v or --version: print QtiPlot version and release date

• -x or --execute: execute the script file given as argument

• -X: execute the script file given as argument without displaying the user interface. Warning: 2D plots are not correctly handledin this mode!

1.3 General Concepts and Terms

Several plots and all the data related to these plots can be saved in a project file. The project is therefore the main container ofQtiPlot. The following screenshot gives an example of a typical session. This example shows the log panel at the top of theworkspace, the project explorer at the bottom, plus a table and a plot window. Other windows are either docked or hidden.

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Figure 1.1: A typical QtiPlot session

General note on MDI style windows. QtiPlot uses a Multiple Document Interface (MDI) style for its sub-windows (for examplegraph and table windows, etc.). This is a convenient mechanism for placing sub-windows on a single parent window (the projectwindow). Such collections of windows are then handled as a group when dragging or minimizing the main window. However,the behavior of maximized sub-windows is one feature of the MDI interface that may cause some confusion at first. As wouldbe expected, sub-windows maximize to the size of the main window’s workspace rather than to the size of the screen, butthe default for maximized sub-windows is to have no title bar. As a consequence, there are no control boxes attached to thewindow, leaving the (incorrect) impression that once maximized, control boxes can no longer be used to minimize, normalize orclose the sub-window. However, control boxes for a maximized sub-window are still present, they have just been moved to theextreme right hand side of the main window’s menu bar. Since only one sub-window can be maximized at a time, there is noambiguity regarding which sub-window this set of control boxes will operate upon. Finally, as a reminder of which sub-windowis maximized, the Name and label of the maximized sub-window are appended to main window’s title as:

"QtiPlot - ProjectName - [WindowName - WindowLabel]"

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There are numerous commands available in QtiPlot. The specific subset of commands available depends on the element whichis selected. Therefore, the main menu bar changes when you select a particular element of the project. Moreover, you can accessthe set of commands relevant to a given element by activating the context menu with the right button of the mouse when themouse pointer is floating over the chosen element.

In a project, the containers which can be used are:

A Table A table is a spreadsheet like object which can be used to store the data you are entering. The table is contained in itsown window (the Table Window). It can be used to perform some calculations and statistical analysis of that data. In eachtable, columns can be labeled as X-values or Y-values for 2D-plotting, or Z-values if you plan to build a 3D-plot.

A table can be created using the New Table command. There are then several ways to fill the table with data. If youwant to read your data from an ASCII file, you can import it from the file into a table using the Import -> Import ASCII...command. You can also manually enter each value from the keyboard. Finally, you can fill the table with the results ofevaluating a mathematical function using the (Set Column Values... command from the Table menu)

An Excel Workbook On Windows operating systems where Microsoft Excel is available you can create an Excel workbook asan OLE instance in QtiPlot workspace. Excel workbooks can be created using the New Excel command and are managedas a special type of QtiPlot child windows. They can be controlled via their context menu (right click on the windowtitle bar to make it pop-up). All QtiPlot window functions (save, copy, duplicate, export, print, hide, close, etc...) can bereached via this menu.

A Matrix A matrix is a special table which is used to store the data points for surface 3D plots. It contains Z-values and doesn’tinclude any column or row which could be designed as X-values or Y-values. Nevertheless, you can specify the X-valuesand the Y-values with the Set Dimensions... command from the Matrix menu.

A matrix is created using the New Matrix command. If you want to read matrix data from an ASCII file, you can importthe data from the file into a table using the Import -> Import ASCII... command, and then convert this table to a matrixwith the Convert to Matrix. In the same way as for tables, you can also fill a matrix with the results of evaluating a functionz=(i,j) in which i and j are row and column numbers (Set Values... command from the Matrix menu)

A Graph A graph can contain one or several layers. A layer consists of axes, text items, graphics, and a single plotting areabounded by the axes lines. One or more curves, generated from data or functions, are placed into the plotting area to createa plot. Layers and their contained plots can be arranged in many ways to build matrix of plots. Throughout this document,the term plot window is used as a synonym for a graph.

A new layer can be added to an existing graph with the Add Layer from the Graph menu. you can also remove an existinglayer with the Remove Layer, but if you remove a layer, the plot on that layer will also be deleted. You can also copy alayer from one graph to another, or copy an existing graph into another (the window will be added as a new layer - see thesection on Multilayer Plots for more details).

Curves can be added to a plot in several ways. You can select data from tables or matrices to generate the curve, or, createa curve from a function of one or two variables (see sections 2D plots and 3D plots).

A Note This window is a text container which can simply be used to insert comments into a project, but is really far morepowerful than that. It can be used as a calculator, for executing single commands, and for writing scripts.

The Results Log Window This window is used to store the results of all calculations which have been done. If this window isnot visible, you can find it with the Project Explorer or with the Results log.

The text in the log window is also saved in the project file, so that when you load a previously saved project, the results-logpanel is re-filled with the results of previous calculations.

The Project Explorer This window is used to list all the windows contained in a project. The Project Explorer gives quickaccess to all elements of a project, hidden or visible. It can be used to perform some operations on the listed windows suchas hiding a window, renaming a window, etc.

A project file can include several independent projects. In this case, the containers of each project are stored in differentfolders.

The Quick Help Window This window is used to display the help pages available in the documentation for the main dialogs inQtiPlot. It can be opened using the Quick Help command from the View menu or by a click on the Help button availablein any of the QtiPlot dialogs that support the quick help system.

The Scripting Console This window is mainly used to display error messages during the execution of Python scripts launchedfrom note windows. It can be opened/closed using the Console command from the View menu.

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1.3.1 Tables

When working with data, tables are the main focus of QtiPlot. Fundamentally, a table is simplified spreadsheet contained in aWindow which can be used to control, edit, and convert data. Tables are also highly customizable: all colors and font preferencescan be set using the Preferences... command of the View menu, and you can resize a table in terms of rows and columns usingthe Table menu with Rows or Columns.

Figure 1.2: The QtiPlot table

Every column of a table has a label, and can be assigned a format: numeric, text, date or time. Each column can also have oneof the following flags set: X, Y, Z, X-error, Y-error, label, or none (i.e., a simple column without any special flag). X flaggedcolumns are the abscissae while Y flagged columns are the ordinates used when creating a 2D plot from data. A column musthave either the X or Y flag set to be available for use in a 2D plot. The X-error and Y-error columns can be used to add error barsto a curve in a 2D plot. Flags can be changed using the Column options dialog. To reach this dialog, simply double-click on thecolumn label or use the Column Options... command from the Table menu.

A table column is selected by left clicking on it’s label. Multiple columns are selected in one of 2 ways. First, if the columns areadjacent, it is most convenient to left click on the first desired column’s label and, while holding the left mouse button down, dragthe mouse pointer over the labels of the column you wish to select. Second, in the case where desired columns are not adjacent,you can select additional columns by keeping the Ctrl key pressed while left clicking on the desired column’s label. This alsoallows you to deselect specific columns. You can select all the columns of a selected table by pressing (Ctrl+A).

You can perform various operations on selected columns : fill with data, normalize, sort, view statistics and finally, generatecurves from your data. All these functions can be reached by right clicking on the column label or by using the Table menu.

All other table functions: rename, duplicate, export, print, and close can be reached via the context menu (right click anywherein the table outside the column labels area).

You can cut, copy and paste data between tables or between a table and another application (Excel, Gnumeric, etc.).

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You can import single or multiple ASCII files using the Import -> Import ASCII... command from the File menu. Of course youcan also export the data from a table to a text file using the Export ASCII dialog.

1.3.2 Excel workbooks

Excel workbooks are available only on Windows operating systems if Microsoft Excel is installed. An Excel workbook can becreated using the New Excel command. You can also open an Excel file as an OLE instance in QtiPlot workspace if the ImportExcel files using method defined in the General tab of the Preferences dialog is set to New Excel. Excel files can be openedthrough the Open Excel command from the File menu or you can directly drag-and-drop them into the QtiPlot workspace.

When an Excel workbook is created in QtiPlot, a window type oriented menu called Excel will be available in the menu bar of theapplication. From this menu you can perform various operations with the data in the workbook: you can convert a data selectionor entire worksheets to QtiPlot tables or export data to ASCII files. You can also convert Excel charts to QtiPlot graph windowsor export them as image files. Only the image file formats supported by Excel can be chosen for this last operation.

Figure 1.3: Working with Excel workbooks in QtiPlot

The Excel workbook is managed as a special type of QtiPlot child window which can be controlled via its context menu (rightclick on the window title bar to make it pop-up). All QtiPlot window functions (save, copy, duplicate, export, print, hide, close,etc...) can be reached via this menu.

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Figure 1.4: Context menu for Excel workbooks

Excel specific options can be customised via the Properties dialog. The workbook can be saved as an external Excel file linkedto the project or as an internal object in the QtiPlot project. If you choose to save it as an external link it is beneficial to save theExcel file in the same folder as the QtiPlot project or in a subfolder under it and then set Excel file path relative to QtiPlot projectpath to make them more portable.

Figure 1.5: Properties dialog for Excel workbooks

You can cut, copy and paste data between QtiPlot tables and Excel workbooks. Please note that when copying data from Excelworkbooks QtiPlot will only copy the number of digits displayed in Excel rather than the full precision values.

You can also make QtiPlot plots directly from data in an embedded Excel workbook, by selecting the data range and then openingthe Plot menu and choosing a graph type, but the available graph types are largely limited especially for 3D graphs.

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1.3.3 Matrix

The matrix is a special table which is used for data which depends on two variables. This special table can be used to create3D plots as well as 2D image/contour plots via the Plot 3D menu and the 3D plot toolbar. One difference between a tableand a matrix is that matrices may function in one of two modes: they can display data in table form or they can display animage. Therefore matrices can be used as a basic image viewer and also as an image editor, since they implement some imagemanipulation functions like: 90 degrees rotation, horizontal and vertical mirroring, etc.

In a matrix there is no special column nor special row for X or Y labels or values. Nevertheless, you can specify an X-scale anda Y-scale with the Set Dimensions....

Figure 1.6: The QtiPlot matrix

The values which are stored in a matrix can be generated from a function of the form z=f(i, j, x, y) with the Set Values...command, i and j being the column and row numbers and x and y the corresponding coordinates. They can also be read directlyfrom an ASCII file with the Import -> Import ASCII... command or from an image file.

1.3.4 Plot Window

The plot window (that is, a graph), provides a container for plotting data. It contains one or more layers, which are the maincontainers of a graph. Each layer contains a plotting area into which curves are placed when creating a plot. Each layer hasits own geometry and graphic properties (background color, frame, etc). The example presented below shows a graph with twolayers which have different geometries.

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Figure 1.7: An example of QtiPlot 2D graph

Each layer can be activated by clicking on its corresponding gray button in the top-left corner of the window.

Some graph elements can be accessed by a double click on an element in a layer. These are:

• the graph itself: this will open the Custom Curve Dialog. You can then add new curves to the plot, or change the way thecurves are plotted.

• The axes or the axes labels: this will open the General Plot Options Dialog. It is used to customize the axes, the numbers andlabels of the axes, and the grid.

• Text items, including the legend: this will open the Text Options Dialog which allows customizing the font of the label and theframe in which it is drawn.

• Arrow/Line items: this will open the Line Options Dialog.

• Image items: this will open a dialog allowing you to customize the geometry and the position of the image.

A left click on a layer element selects it. You can deselect any element by pressing the Escape key. A right click on a layerelement pops-up a context menu allowing quick access to its properties dialog. Last but not least, you should know that QtiPlotprovides multiple selection for objects in a layer. In order to add an object to an existing selection keep the Shift key pressed andclick on the element you want to add to the selection. Elements in a multiple selection can be moved and resized together withthe mouse.

1.3.5 Note

A note can simply be used to insert text (comments, notes, etc) into a project, but is really far more powerful than that. It canbe used as a calculator, for executing single commands and for writing scripts. Evaluation of mathematical expressions andexecution of code is done via a note’s context menu, the Scripting menu or convenient keyboard shortcuts. For information onexpression syntax, supported mathematical functions and how to write scripts, see here.

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Figure 1.8: The QtiPlot Note Window

Note windows provide powerful text editor functionalities, particularly helpful when writing scripts: customizable Python syntaxhighlighting, line number display, find and replace text, and autocompletion suggestions for words having more than two charac-ters. You can manually trigger autocompletion by using Ctrl+U. The colors used for syntax highlighting can be customized viathe Notes tab in the Preferences dialog.

1.3.6 Results Log Window

This window keeps a history of all analysis which has been done in the project. It panel contains the results of all the correlations,fittings, etc.

Figure 1.9: The QtiPlot Results Log window

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1.3.7 The Project Explorer

The project explorer can be opened/closed using the Project Explorer from the View menu or by clicking on the in the filetoolbar.

Figure 1.10: The QtiPlot Project Explorer

It gives an overview of the structure of a project and allows the user to perform various operations on the windows (tables, graphs,and notes) in the workspace: hiding, minimizing, closing, renaming, printing, etc. These functions can be reached via the contextmenu, obtained by right-clicking on an item in the explorer. When the cursor is moved over a graph or matrix item name a256x256 preview of the window is displayed.

By double-clicking on an item, the corresponding window is shown maximized in the workspace, even if it was hidden before.

From the project explorer window, different objects can be organized into folders. When selecting a folder, the default policy isthat only the objects contained in it will be shown in the workspace window. You can also display all the objects in subfolders ifyou change this policy with the "View Windows" command to "Windows in Active Folder and Subfolders".

1.3.8 The Quick Help Window

This window can be opened/closed using the Quick Help command from the View menu or by a click on the Help button availablein any of the QtiPlot dialogs that support the quick help system.

Figure 1.11: The Quick Help Window

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The main purpose of the quick help window is to display the help pages available in the QtiPlot documentation. It also implementssome of the basic functionalities of a help browser: searching for user defined words in the documentation (with the help of the

and buttons), as well as quick navigation through the recent viewing history (using the and buttons).

1.3.9 The Scripting Console

This window can be opened/closed using the Console command from the View menu. QtiPlot opens it automatically in order todisplay error messages during the execution of Python scripts launched from note windows.

Figure 1.12: The Scripting Console

1.4 Interoperability with other scientific software

QtiPlot can import and export data from and to several scientific programs: OriginLab, Excel and other major office suiteslike LibreOffice and Apache OpenOffice. It can also import Matlab files, LabVIEW TDMS files, dBase, MySQL, SQLite andMicrosoft Access databases. Last but not least easy integration with LaTeX typesetting system is also available.

1.4.1 OriginLab

1.4.1.1 Import of OriginLab projects

QtiPlot can import *.opj project files created with OriginLab versions ranging from 4.1 to 9.3 (Origin 2016). QtiPlot can alsoimport individual workbooks (*.ogw files), matrices (*.ogg files) and graphs (*.ogg files). Since not all of OriginLab featuresare available in QtiPlot sometimes the formating of the data tables or of the plot windows might look different from the originalprojects.

1.4.1.2 Export QtiPlot projects to OriginLab

Starting with version 0.9.9.1 QtiPlot can also export individual project windows, projects folders or entire projects as Origin Cfiles that can be compiled and executed by OriginLab. Again, since not all of OriginLab features are available in QtiPlot the datatables and especially the plot windows might look different when opened into OriginLab.

Saving QtiPlot projects to Origin C files is straightforward: open the File menu, select the Save Window as... or Save Projectas... command and choose the file type Origin project (*.c) from the file dialog.

If you export projects containing 2D graph windows that display images or LaTeX equations QtiPlot will save all these imagesinto a folder with the -images suffix appended to the base name of the exported Origin C file. Therefore if you send the .c file tosomeone else don’t forget to also attach this folder.

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Figure 1.13: Export QtiPlot windows/projects as Origin C files

There are a few preparatory steps that should be undertaken into OriginLab in order to easily open the C files generated byQtiPlot. First of all you should create a new menu using the OriginLab Custom Menu Organizer wizard from the Tools menu:

Figure 1.14: OriginLab - Create new custom menu

In the Custom Menu Organizer dialog you need to right click into the left panel in order to add a new menu, that was renamed toCustomImport in the example screenshot bellow:

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Figure 1.15: OriginLab - New custom menu

Next you need to right click on this new menu and from the popup menu select the option Add Item:

Figure 1.16: OriginLab - New custom menu item

Once the menu item is created you need to select it with the mouse. A new dialog page appears and you can customize it like inthe following screenshot, where we changed the default name to Open QtiPlot and added a Status Bar Text:

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Figure 1.17: OriginLab - Import script

In the LabTalk Script editor you must copy/paste the following code lines:

run.LoadOC(Originlab\\image_utils.c);getfile *.c;if (run.LoadOC(%A) == 0) importQtiPlot;

Once this is done click the Close button of the dialog and press the Yes button when asked to save the changes.

In order to be successfully compiled by OriginLab the C files generated by QtiPlot must be copied into the OriginC folder ofyour OriginLab installation directory, like shown in the screenshot bellow:

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Figure 1.18: OriginLab - Select C file generated by QtiPlot

After the compilation process OriginLab will create a new folder having the base name of the imported C file.

1.4.2 Microsoft Excel

1.4.2.1 Import of Excel files

QtiPlot can import data from spreadsheets stored in binary *.xls, *xlsx files as well as from *.xml Microsoft Excel files, usingdifferent methods. For more details see the Open Excel command.

On Windows operating systems, if Microsoft Excel is installed on your computer, QtiPlot can also import the charts from Excelfiles or even embed Excel workbooks (New Excel command).

1.4.2.2 Export QtiPlot data to Excel

QtiPlot can export data from table and matrix windows as binary *.xls files.

1.4.3 LibreOffice and Apache OpenOffice

1.4.3.1 Import

QtiPlot can import data from spreadsheets stored in binary *.ods files as well as from flat XML *.fods files (see Open ODFSpreadsheet command).

1.4.3.2 Export

QtiPlot can export data from table and matrix windows as binary *.ods files if either LibreOffice or Apache OpenOffice areinstalled on your computer.

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Chapter 2

Drawing plots with QtiPlot

2.1 2D plots

A 2D plot is based on curves which are defined by Y values as functions of X values. There are two ways to obtain a 2D plotdepending on the way the (X,Y) values are defined:

• You can have your (X,Y) values in a table. You need to select at least one column as X values and one column as Y values.This is specified using the "Plot Designation" option found in the Column Options... command. Then you select the columnsand use one of the commands in the Plot menu to plot the data.

• If you want to plot a function, you don’t need a table at all. You can plot the function directly with the New Function Plot...command. This opens the corresponding dialog box where you define the mathematical expression of your function.

• These two methods can be combined by first defining a table, and then filling it with the results of evaluating your function.This is done with the Set Column Values... command. Then you select the columns and use one of the commands from thePlot menu to plot the data.

In each of these cases, QtiPlot will create a new graph with the plotted curve placed on a new layer. Data plots and function plotscan also be added to an existing layer using either the New Function Plot... command command or by right clicking within thearea of the desired plot to pop up the plot’s Graph Menu, and then selecting Add...Add Function.

Once the plot is created, you can customize all the graphic items in the plot using commands from the Format Menu. You canadd new items (text labels, lines or arrows, new legend, images) to the plot with the commands of the Graph Menu.

2.1.1 2D plot from data.

The data must be stored in a table. There are two methods for inserting your (X,Y) values into the table: you can type themdirectly from the keyboard, or you can read them from a file. Here we will use the first solution, refer to the Import -> ImportASCII... command to use the second.

The first step in this example is to create an empty project with the New Project command from the File menu. You can also usethe Ctrl-N key or the icon from the File toolbar. Next create a new table using the New Table command from the File menu,the Ctrl-T key, or the icon from the File toolbar.

A newly created table has two columns (one for X and one for Y) and 30 rows. You can add rows and columns by selecting arow or a column and using the right mouse button. You can also modify the number of rows and columns with the Rows andColumns from the Table menu. Try setting the number of rows to 7, which will match the table shown below. Then enter thevalues as shown (you can of course use your own data). You should now have this table:

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Figure 2.1: A simple 2D plot: the table.

You must next select the data to be plotted. To select the 2 columns of data just entered, left click on the title of first column anddrag the mouse pointer over to the title of the second column while holding the left mouse button down. Now, with the columnsselected, you can build the plot (here a simple 2D scatter) with the Scatter command from the context menu, or by clicking onthe corresponding icon from the Plot toolbar or with the Scatter command from the Plot menu. A plot is created in the plottingarea of a new layer on a new graph. Default options are used for for all newly created elements. You can customize the defaultoptions with the preferences dialog. The default options will produce the following:

Figure 2.2: A simple 2D plot: the default plot.

You can now customize your plot and the elements of the parent layer. Double clicking on any point will open the Custom curvesdialog, which is used to modify the plotted symbols. A double-click on any axis opens the general plot options dialog, where youcan change scales, fonts for the axis labels, etc. You can also add grid lines on X or Y axes, etc. Finally, a double click on anytext item (X title, Y title, plot title) allows you to change the text and its presentation. As an illustration, several changes havebeen made to the above plot. The final result is:

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Figure 2.3: A simple 2D plot: the plot finished.

Finally, you should save your project in a ’.qti’ file using the Save Project command from the File menu or by typing the Ctrl-Skey, or by clicking the icon from the File toolbar. Depending on your needs, you can export the plot in any of several standardimage file formats using the Export Graph -> Current command from the File menu, or by entering the Alt-G key.

There are several types of curves which can be plotted from a table. They are presented in the Plot menu

It is possible to use up to four axes for the data:

Figure 2.4: A 2D plot with two Y axes.

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In addition to the customizations which have been already been described, for the figure above the axes used for each curve weredefined using the Custom Curves Dialog, and two arrows were added with the Draw Arrow. Note that the table must be modifiedby the addition of a second column of Y data before the second curve can be drawn in the plotting area (using Graph Menu, andthen selecting Add...Add/Remove Curve).

2.1.2 2D plot from function.

There are two ways to obtain such a plot: you can plot a function directly, or fill a table with the values calculated from a functionand create the plot in the usual way.

2.1.2.1 Direct plot of a function.

If you just want to plot a function, you can use the New Function Plot... command from the File menu, click the icon in theFile toolbar, or simply enter Ctrl-F.

This command will open the Add Function Curve dialog. You can then enter the mathematical expression of your function, theX range to be used for the plot, and the number of points in the X range. Besides classical Y=f(X) functions, you can also defineparametric and polar functions.

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Figure 2.5: Direct plot of a function.

2.1.2.2 Filling of a table with the values of a function.

If you want to work not only with the plot but also with the resulting data, create a new table as explained in the previous section.Then fill this table with the values of the function evaluation using the Set Column Values... command.

Let’s obtain the same plot as in the previous example. Create a new table (key Ctrl-T), select the first column and use the SetColumn Values... command either from the context menu, or the Table menu. The row number can be used in functions byreferencing the row number symbol, i. For a range of 0.01-30 in 300 steps (0.01 per step) enter the function expression i/10 anduse 300 rows. (Note that since row numbering starts at 1, to actually get the X range used in the last example (0-30 over 300points), we would need to define the function expression as (i-1)*30/299.)

Figure 2.6: Function plot: filling of the X column.

The second step is to select the second (Y) column and use the Set Column Values... command to set up the function. Theexpression is a function of the X values (that is the first column) which is named col(1). Enter sin(col("1"))+cos(col("1")/3+1)as the function and click apply to generate the values in the Y column.

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Figure 2.7: Function plot: filling of the Y column.

Once the table is ready, you just have to build the plot as explained in the previous section.

2.2 3D plots

3D plots are generated from data defined as Z=f(X,Y). As with 2D plots, there are two ways to obtain a 3D plot, depending onthe way the (X,Y,Z) values are defined:

• You can have your Z values in a matrix. QtiPlot will consider that all the data present in the matrix are Z values, and the X andY values are defined as functions of the column and row numbers.

The data in the matrix can be entered in several ways:

– one by one from the keyboard,

– by reading an ASCII file into a table and converting the table into a matrix,

– by setting the values with a function.

• If you want to plot a function, you don’t need a matrix. You can plot a function directly using the New 3D Surface Plot...command. This will open the corresponding dialog box where you define the mathematical expression of your function.

There are several kinds of 3D plots which can be selected, see the Plot 3D menu section of the reference chapter for a list of theavailable plots.

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Figure 2.8: Example of a 3D Plots.

3D plots use OpenGL so you can easily rotate, scale and shift them with the mouse. Using the 3D plot settings dialog or theSurface 3D Toolbar, you can change all the predefined settings of a three dimensional plot: grids, scales, axes, title, legend andcolors for the different elements.

There are several types of plots which can be built from a matrix. They are presented in the Plot 3D menu

2.2.1 Direct 3D plot from a function

This is the simplest way to obtain a 3d plot. Use the New 3D Surface Plot... command from the File menu or simply enterCtrl-Alt-Z. This will open the following dialog box:

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Figure 2.9: Definition of a new surface 3D plot

You can enter the function z=f(x,y) and the ranges for X, Y and Z. Then QtiPlot will create a default 3d plot:

Figure 2.10: The 3D surface plot created using defaults

You can then customize the plot by opening the Surface plot options dialog. You can modify the axis ranges and parameters, add

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a title, change the colors of the different items, and modify the aspect ratio of the plot. In addition, you can use the commands ofthe 3D plot toolbar to add grids on the walls or to modify the style of the plot. The following plot illustrates some of the possiblemodifications:

Figure 2.11: The 3D surface plot after customization.

If you want to modify the function itself, you can use the surface... command which can be activated from the context menuwith a right click on the 3D plot. This will re-open the define surface function dialog box.

2.2.2 3D plot from a matrix

The second way to obtain a 3D plot is to use a matrix. Therefore, the first step is to fill the matrix. This can be done by evaluationof a function.

The New Matrix command create a default empty matrix with 32x32 cells. Then use the Set Dimensions... to modify the numberof rows and columns of the matrix. This dialog box is also used to define the X and Y ranges.

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Then use the Set Values... command to fill the cells with numbers. The ranges of X and Y defined in the previous step are notknown by this dialog box, so the function must be defined with row and column numbers (i and j) as parameters (see the sectionset-values for details).

The other way to obtain a matrix is to import an ASCII file into a table with the Import -> Import ASCII... command from theFile menu. The table can then be transformed into a matrix with the Convert to Matrix from the Table menu.

You can then use this matrix to build a 3D plot with one of the commands from the Plot menu.

2.3 Multilayer Plots

Graph windows can contain multiple layers, each with different characteristics. Each layer has a corresponding, numberedbutton. A button appears pressed when its layer is the currently active layer. Only one layer is active at a time, and the plot tools(zoom, cursors, drawing tools, delete and move points) only operate on this layer. A layer is made active by clicking on it or onits corresponding button.

To arrange layers use the Arrange Layers... dialog. You can add or remove layers with the Add Layer and Remove Layer orcopy/paste layers from one multilayer window to another. All these functions can be reached via the Graph menu, by using thePlot toolbar or via the context menu (right click in the multilayer window anywhere outside a layer area).

You can resize and move a layer using the Layer geometry dialog (Select the Geometry tab in Plot... from the Format Menu).You can also arrange and resize layers by hand using the mouse. First, select the layer to be modified or moved and then selectthe layer’s plot area by left clicking on a border line (an axis line) of the plot area. QtiPlot will draw a box outlining the plot areawith drag handles at the corners and midpoints of the sides. The cursor will assume a shape based upon where it is located on thelayer: a hand shape when inside the plot area, or a double ended arrow when over one of the drag handles. The cursor’s function,which is invoked by pressing the left mouse button, is indicated by this shape.

Pressing and holding the left mouse button when the cursor assumes the hand shape allows dragging the entire layer with themouse. Releasing the mouse button will drop the layer at the new position. Pressing and holding the left mouse button when thecursor assumes one of the double ended arrow shapes allows dragging the corresponding border of the plot area, scaling the layeras needed. Releasing the mouse button will drop the border and apply the new scale value. Grabbing a midpoint handle movesonly the corresponding border, while grabbing a corner handle allows simultaneous dragging of both corresponding borders.Dragging the corner handles does not preserve the aspect ratio of the layer.

You can also conveniently resize a layer using the mouse wheel in combination with either the Ctrl, Alt, or Shift keys. In orderto use the mouse wheel, the desired layer must be selected, either by clicking in the layer or by using one of the layer selectionbuttons. It is not necessary to have the plot area selected, although the wheel functions will work in either case. The wheelfunctions work as follows: Pressing and holding the Ctrl key while rotating the wheel resizes the height, pressing and holdingthe Alt key while rotating the wheel resizes the width, pressing and holding the Shift key while rotating the wheel resizes boththe height and width. Note that in this last case (Shift+Wheel), the aspect ratio of the layer is preserved.

2.3.1 Building a multilayer plot panel

This is the simplest way to obtain a multilayer plot. It can be used if you want to build a panel of plots with a simple arrangement:2 plot in a row or in a column, or 4 plots in 2 rows and 2 columns.

You can select two columns with Y-values in a table, and then use one of the Panel commands in the Plot menu. QtiPlot willcreate a panel of plots in which the size of the different elements of each plot are synchronized.

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You can then customize the plots. If you want to change the arrangement of the panel, use the Arrange Layers... from the Graphmenu. In this case, keep in mind that each plot is in its own layer whose surface area is one half or one quarter of the window’ssurface area. So, if you want to share an element between two plots (for example a text label), you need to add it in a new layer(see the Add Text for more details).

2.3.2 Building a multilayer plot step by step

If you need to build a more complex multilayer plot, you can define it step by step.

The first step is to build your first plot (for example from two columns of a table). Start by creating a standard graph window:

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Then, select the plot window and use the Add Layer from the Graph menu. This will activate the Add Layer dialog. If youchoose "Guess" you will obtain a panel with two columns, if you choose "corner" you will obtain two superposed layers, youcan then modify these two layers.

If you want to build a panel with two rows, you can use the Arrange Layers... to automatically rearrange the layers.

Then select the second (empty) plot and use the Add/Remove Curves... command to select the Y-values from one of the tablesof the project.

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After this, you can customize your plot. At the end, the modifications done on the axis or on the axis labels may have modifiedthe geometry of the two plots. You can again rearrange the two plots by using the Arrange Layers... a second time.

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Chapter 3

Command Reference

The active items appearing in a menu depends upon which project window is active. For example, if the active window is a table,then all the items related to table functions are enabled and the others are automatically disabled.

3.1 The File Menu

Many of the commands from the File Menu are also linked to corresponding icons in the File Toolbar. Clicking one of theseicons will directly execute the linked command.

3.1.1 File-> New ->

3.1.1.1 New -> New Project (Ctrl-N)

Creates a new QtiPlot project file. If another project is already open and has been saved at least once, it will be closed before thenew project is created. If another project is open but has never been saved, a dialog will be opened to ask if the current projectshould be saved.

3.1.1.2 New -> New Folder (F7)

Adds a new folder to the project. The new folder is added to the current folder.

3.1.1.3 New -> New Table (Ctrl-T)

Creates a new (empty) table and adds it to the project. The empty table will have 30 rows and 2 columns. The number of rowsand columns can be changed with the Rows and Columns of the Table menu.

The properties of each column (numeric format, column width, etc) can be modified using the Column Options... command ofthe Table menu. See the table section for more details.

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3.1.1.4 New -> New Excel

Creates a new (empty) Excel workbook as an OLE instance in QtiPlot workspace and adds it to the project. This function onlyworks on Windows operating systems where Microsoft Excel is available. See the Excel section for more details.

3.1.1.5 New -> New Matrix (Ctrl-M)

Creates a new (empty) Matrix and adds it to the project. The empty matrix will have 32x32 cells. These dimensions can bechanged using the Set Dimensions... of the Matrix menu

See the matrix section for more details.

3.1.1.6 New -> New Note

Creates a new note window and adds it to the project. A note is a simple text window which can be used to add comments to thecurrent project.

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3.1.1.7 New -> New Graph (Ctrl-G)

Creates a new 2D plot, that is, a graph window with a single, empty layer, and adds it to the project. Current defaults are used tocreate the layer, which is just a framework into which you add curves with the Add/Remove Curves... command.

3.1.1.8 New -> New Function Plot -> New Function Plot... (Ctrl-F)

Opens a dialog which is used to create a 2D plot by specifying an analytical function. See the 2D plot section of the tutorial fora general overview of this function.

The function can be defined in Cartesian, parametric or polar coordinates, see the Add Function... command for more details.

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3.1.1.9 New -> New Function Plot -> New Parametric Function Plot...

Opens the parametric coordinates tab of the add function dialog which is used to create a 2D plot by specifying two parametricalfunctions: X=f1(m) and Y=f2(m).

3.1.1.10 New -> New Function Plot -> New 3D Surface Plot... (Ctrl-Alt-Z)

Opens a dialog which is used to create a 3D plot by specifying an analytical function. Only Cartesian coordinates are available.See the 3D plot section of the tutorial for more detail on this function.

3.1.1.11 New -> New Function Plot -> New 3D Parametric Surface Plot...

Opens the parametric coordinates tab of the surface dialog which is used to create a 3D plot by specifying the (X,Y,Z) data pointsas functions of the latitude and longitude variables u and v. Only Cartesian coordinates are available.

3.1.2 File -> Open (Ctrl-O)

Opens an existing QtiPlot project file (.qti). If your project has been saved in a compressed format, you must select the .qti.gzfile format.

This command can also be used to open projects which have been built with Origin software.

3.1.3 File -> Open Excel

Opens a file dialog permitting you to select an Excel file. When a file is selected and opened, QtiPlot creates a new table foreach sheet in the file and reads the spreadsheets into the tables. Depending on the operating system QtiPlot provides three importmethods. The first one (using the ExcelFormat library) can fail for certain files, therefore QtiPlot provides a second solutionwhich needs either OpenOffice or LibreOffice installed on your computer. On Windows platforms, if the file contains graphs,QtiPlot will also import them, but only if you have Excel installed on your machine. The import method used by QtiPlot can beset via the General tab of the Preferences dialog.

3.1.4 File -> Open ODF Spreadsheet

Opens a file dialog permitting you to select an OpenOffice spreadsheet file. QtiPlot can import data from spreadsheets stored inbinary *.ods files as well as from flat XML *.fods files. When a file is selected and opened, QtiPlot creates a new table for eachsheet in the file and reads the spreadsheets into the tables.

3.1.5 File-> Open Image File (Ctrl-I)

This command adds a new graph window to the QtiPlot project and loads an image file into it. The image can be resized andmoved around in the graph window if desired. It can also be copied and inserted into another 2D plot with a result similar to thatobtained using the Add Image. An image can also be used to generate an intensity matrix (see the Import Image... command).

3.1.6 File -> Append Project... (Ctrl-Alt-A)

Appends an existing QtiPlot project file (.qti) to the current project as a new folder.

This command can also be used to append projects which have been built with Origin software.

3.1.7 File-> Recent Projects

Opens a list of the most recently used QtiPlot project files. You can open one of these files by selecting it from the list. If the fileno longer exists or has been moved, an error message will pop-up and the filename will be deleted from the list.

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3.1.8 File -> Close

Closes current project, without quitting the application.

3.1.9 File-> Save Project (Ctrl-S)

Saves the current project. If the project hasn’t been saved yet (an "untitled" project), a dialog will open, allowing you to save theproject to a specific location. In a project file, all settings and all plots are stored in ASCII format.

If the project includes large tables, it may be useful to save the project in a compressed file format. The free zlib library is usedto save files in gzip format ( .qti.gz ).

3.1.10 File-> Save Project as... (Ctrl-Shift-S)

Saves the current project under a file name different than the current name.

3.1.11 File-> Save Window as...

The Save Window as... command allows you to save tables and graphs from from one Qti project into a newly created projectfile. The command opens a standard file-save window in which you select the new project’s name and location. Projects maybe saved in either compressed or uncompressed form. If a graph window is selected, the new project will contain the graph andit’s associated tables/matrices. If a table, matrix or note is chosen, the new project will contain only the selected table, matrix ornote. In this case, dependent graphs are not included in the new project.

3.1.12 File -> Open Template

Opens an existing QtiPlot template file (.qpt). This command will create a new graph window with one or more empty layerscreated using the same graphical parameters (window geometry, fonts, colors, etc). as the layers in the saved template.

The first figure below is a graph which was saved as a template. The second figure is the graph with a new, empty layer createdusing the Open Template command to load the saved template file.

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You just have to add curves with the Add/Remove Curves... command, but note that the style used to draw these curves is notkept in the template.

3.1.13 File -> Save as Template

Save the active graph as a QtiPlot template file (.qpt). The resulting template will contain all of the layers from the graph,including images, text labels (axes, etc), and any graphical parameters, including the positions and sizes of the layers. Plotteddata, the style used to draw curves, and any associated scales are not saved in the template.

3.1.14 File-> Print (Ctrl-P)

Prints the active plot. A print dialog is opened where you can select the printer, different paper sizes, etc.

3.1.15 File-> Print Preview

Displays a print preview for the active window. You can use this dialog to print the previewed window.

3.1.16 File-> Print All Plots

Prints all plots in the project. A print dialog is opened where you can select the printer, different paper sizes, etc.

3.1.17 File -> Export Graph

The Export Graph command appears in the file menu whenever a graph window is selected. This command opens the ExportGraph dialog which can be used in order to save the active graph window in a chosen image format.

3.1.17.1 Export Graph -> Current (Alt-G)

This selection will save the active graph using one of the image formats supported by QtiPlot.

3.1.17.2 Export Graph -> All (Alt-X)

This selection will save all graphs in the project using one of the image formats supported by QtiPlot.

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3.1.17.3 File -> Create Open Document Presentation...

This selection will save all the graphs in the project in an Open Document Format file (.odf) that can be opened and edited withOpenOffice.

3.1.18 File -> Export

The Export command appears in the file menu whenever a non-graph window (i.e., Table or Matrix) is selected.

3.1.18.1 Export ASCII

This command opens the Export ASCII dialog, with which you can save the active table or matrix in a chosen ASCII format(".dat", ".html", ".odf", ".tex", ".txt", and ".xls" are available).

3.1.18.2 Export Excel

This command opens the Export ASCII dialog with the ".xls" format pre-selected. This saves the active table or matrix as anExcel spreadsheet.

3.1.18.3 Export to PDF (Ctrl-Alt-P)

This command opens a generic file dialog to save the active window as a PDF document.

3.1.19 File -> Import

3.1.19.1 File -> Import -> Import ASCII... (Ctrl-K)

Opens the Import dialog used to import ASCII data files. The file to import, and the options for importation are set in this dialog.

3.1.19.2 File-> Import Image...

Using this command, an image may be loaded into a QtiPlot project and converted into an intensity matrix. For each pixel, anintensity between 0 and 255 is computed from the intensities of the three colors red, green and blue.

This example shows the 3D plot drawn from the intensity matrix obtained from the QtiPlot logo.

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3.1.19.3 File -> Import -> Database...

This command opens a sub-menu allowing to import database files in one of the following formats: dBase (.dbf), MicrosoftAccess (.mdb), SQLite (.db), MySQL and PostgreSQL. The file formats available for import may vary from one operatingsystem to another.

If you wish to import Microsoft Access database files (.mdb) on Windows you must first install the Microsoft Access DatabaseEngine available for download from the following link: https://www.microsoft.com/en-us/download/details.aspx?id=13255. Youmust, of course, pay attention to the architecture of your Windows system and install the 64-bit version of the Access Databasedriver if you’re using a 64-bit version of QtiPlot.

Each of the commands in the database format sub-menu opens a file dialog or a server connection dialog allowing the selectionof a database. After the completion of the database selection step, depending on the database format, QtiPlot might also open atable selection dialog allowing to choose the tables/views to be imported. If you choose to import an SQL database (MySQL,PostgreSQL or SQLite), this dialog also makes possible to perform an SQL query prior to the import operation.

3.1.19.4 File -> Import -> Matlab...

This command allows to import Matlab (.mat) files.

3.1.19.5 File -> Import -> Sound (WAV)...

This command allows you to import an uncompressed sound (.wav) file (PCM format).

3.1.19.6 File -> Import -> NI (TDMS)...

This command allows to import files in the TDMS format (.tdms), a file format developed by National Instruments which isoptimized for saving measurement data to disk. This command opens the Open TDMS File dialog that gives total control overthe import process.

3.1.20 File -> Quit (Ctrl-Q)

Closes the application. You will be asked whether or not you want to save any changes.

3.2 The Edit Menu

3.2.1 Edit -> Undo (Ctrl-Z)

Undo the last change to a note or matrix. Currently this function does not work for anything other than notes and matrices.

3.2.2 Edit -> Redo (Ctrl-Shift-Z)

Reverse the effect of the last "Undo" operation on a note or a matrix. Currently this function does not work for anything otherthan notes and matrices.

3.2.3 Edit -> Cut Selection (Ctrl-X)

While this command does not currently appear in the Edit Menu, the functionality is provided with the Ctrl-X key. The commandcopies the current selection to the clipboard and deletes the selection. It currently works for tables and for 2D plots objects.

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3.2.4 Edit -> Copy Selection (Ctrl-C)

Copies the current selection to the clipboard. It currently works only for layers.

3.2.5 Edit -> Paste Selection (Ctrl-V)

Pastes the content of the clipboard to the active window. It currently works only for layers.

3.2.6 Edit -> Delete Selection (Del)

Removes the current selection from the project. It currently works only for layers.

3.2.7 Edit -> Delete Fit Tables

Each time you fit your data to some mathematical model, a new table is created in which to put the results of the fit (i.e. thevalues computed by the model). These tables can be used to plot comparisons of experimental and fitted values. If you havecompleted several tentative fits, a number of fit result tables may be present in your project. This command allows you to removethe results of all the different fits that you have tested.

3.2.8 Edit -> Clear Log Information

Allows the user to clear the log panel. All history information about analyses performed by the user will be deleted from theproject file. The log panel will then be empty.

3.2.9 Edit -> Preferences...

Opens the Preferences dialog.

3.3 The View Menu

3.3.1 View -> Toolbars... (Ctrl-Shift-T)

Opens a pop-up menu allowing you to enable/disable tool bars.

3.3.2 View -> Project Explorer (Ctrl-E)

Opens/Closes the Project Explorer dock window, which gives an overview of the structure of a project and allows the user toperform various operations on the windows (tables and plots) in the workspace.

3.3.3 View -> Results log

Opens/Closes a panel displaying a history of all data analysis operations performed by the user.

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3.3.4 View -> Undo/Redo Stack...

Shows/Hides the matrix Undo/Redo Stack window. The Undo/Redo stack contains the history of editing changes for a selectedmatrix. When any matrix is selected, its Undo/Redo information will be copied into this window. If another matrix is selected, thedata for that matrix will be swapped into the list. Only one matrix can have it’s Undo/Redo information showing at a time. Thedepth of the stack (i.e., number of possible undo steps) is set in the "Applications" tab in the "General" section of the Preferencesdialog. Each list entry consists of the name of the matrix followed by the identity of the cell that was edited. Each edit pushesanother entry onto the list. The current position in the Undo/Redo history is highlighted. Undo (Ctrl-Z or ) or Redo (Ctrl-Shift-Z or ) will move the highlight as appropriate. The history can be rapidly traversed by clicking on a stack entry, which will movethe highlight to the clicked entry and revert the matrix to that point in the history. Each time the project is saved, the save-projecticon ( ) is placed next to the stack entry that was highlighted at the time of the file save operation. This serves as a reminder tothe user of exactly what version of the matrix resides on disk.

3.3.5 View -> Quick Help

Opens/Closes a window displaying the QtiPlot documentation pages.

3.3.6 View -> Console

Shows/Hides the scripting console window.

3.4 The Scripting Menu

3.4.1 General Scripting Commands

These are commands that always appear in the Scripting menu, regardless of the window type selected

3.4.1.1 Scripting -> Scripting language

Opens a dialog used to select the scripting language for the current project.

3.4.1.2 Scripting -> Restart scripting

Reinitializes the scripting environment.

3.4.1.3 Scripting -> Add Custom Script Action...

Opens the Custom Action dialog, which allows you to define menu items and toolbar buttons that launch Python scripts.

3.4.2 Notes Specific Scripting Commands

If the active window in the project is a Notes window, the following additional items will also be available in the scripting menu:

3.4.2.1 Scripting -> Execute (Ctrl+J)

Executes the line where the mouse cursor is placed in the Notes window.

3.4.2.2 Scripting -> Preferences... (Ctrl+Shift+J)

Executes all lines in the Notes window.

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3.4.2.3 Scripting -> Evaluate (Ctrl+Return)

Evaluates the line where the mouse cursor is placed in the Notes window.

3.4.2.4 Rename Tab...

Opens a standard dialog which permits changing the name of the active notes tab.

3.4.2.5 Add Tab

Adds a new tab to the active notes window. The new tab will be named untitled by default. The tab may be renamed at any timeusing the Rename Tab... command.

3.4.2.6 Close Tab

Closes (deletes) the active Notes tab. The contents of the tab will be lost. No warning is given!

3.5 The Graph Menu

This menu is only active (visible) when a graph window is selected.

3.5.1 Graph -> Add/Remove Curves... (Alt-C)

Opens the Add/Remove Curves... dialog, allowing easy addition or removal of curves from the active plot layer. This dialog canalso be used to modify a curve which is already plotted by changing the columns which are used as X or Y values. The curve isadded to the currently active layer. If there is no layer on the graph, an error message will pop-up.

3.5.2 Graph -> Add Function... (Ctrl-Alt-F)

Opens the Add Function... dialog. This command is used to add new function curves to an existing layer. New curves are addedto the currently active layer.

3.5.3 Graph -> Add Error Bars... (Ctrl-B)

Opens the Add Error Bars... dialog. You can add error bars to X and/or Y values on an existing plot. Error bars are added to thecurrently active layer.

3.5.4 Graph -> Rescale To Show All (Ctrl-Shift-R)

Rescales the active plot layer after a zoom operation so that all data on the graph is visible. This command does not set anyspecial mode of its own, but unlike the Zoom out command, it does not alter any other mode that may be in effect. Nevertheless,it does delete the zoom history of the rescaled plot.

3.5.5 Graph -> Exchange X-Y Axes

This command is used to swap the X and Y axes of the active plot layer. It remains checked until the axes are exchanged back totheir initial state by a second call of this command.

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3.5.6 Graph -> New Legend (Ctrl-L)

Adds a new legend object to the active layer. You can have more than one legend on a plot. These legends can later be customizedby double clicking on a given legend.

3.5.7 Graph -> Add Color Scale

Adds a new color scale legend object to the active layer. You can have more than one color scale on a plot. These color scalelegends can later be customized by double clicking on a given legend.

3.5.8 Graph -> Add Equation... (Alt-Q)

This command is used to add a Tex formatted equation on a layer. When selected, the cursor changes to an edit text cursor. Youmust then click in the plot area to specify the position of the new Tex equation. A Tex editor will pop-up allowing you to enterthe equation to be displayed and set its properties (color, frame, etc...)

3.5.9 Graph -> Add Text (Alt-T)

This command is used to add text items on a layer. When selected, the cursor changes to an edit text cursor. You must then clickin the plot area to specify the position of the new text box. A text dialog will pop-up allowing you to type the text to be displayedand set all its properties (color, font, etc...)

3.5.10 Graph -> Draw Arrow (Ctrl-Alt-A)

Changes the active layer’s operational mode to drawing mode. You must click on the layer canvas in order to specify the startingpoint for the new arrow, and then click once more to specify its ending point. You can edit the new arrow using the Arrow dialog.Switch back to the normal operating mode by clicking the "Pointer" icon in the Plot toolbar.

3.5.11 Graph -> Draw Line (Ctrl-Alt-L)

Changes the active layer’s operational mode to drawing mode. You must click on the layer canvas in order to specify the startingpoint for the new line, and then click once more to specify its ending point. You can edit the new line using the line dialog.Switch back to normal operating mode by clicking the "Pointer" icon in the Plot toolbar.

3.5.12 Graph -> Add Rectangle (Ctrl-Alt-R)

Draws a rectangular box on the active plot layer. After selecting this command, the pointer changes to a crosshair target. Clickand hold the left mouse button on the active layer to indicate the first corner of the rectangle, then drag the cursor to the oppositecorner of the rectangle. Once the second point is specified, release the left mouse button to draw the rectangle. The pointerautomatically changes back to normal mode.

3.5.13 Graph -> Add Ellipse (Ctrl-Alt-E)

Draws a elliptical shape on the active plot layer. After selecting this command, the pointer changes to a crosshair target. Clickand hold the left mouse button on the active layer to indicate the first corner of the ellipse’s bounding rectangle, then drag thecursor to the opposite corner of the bounding rectangle. Once the second point is specified, release the left mouse button to drawthe ellipse. The pointer automatically changes back to normal mode. Circles may be drawn using this command by setting theheight and width equal. (The object properties dialog can be used to set height and width to exactly the same value.)

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3.5.14 Graph -> Add Time Stamp (Ctrl-Alt-T)

This command is used to add a special label in the active layer which contains the current date and time. The properties of thislabel can be customized like any other label added by the Add Text.

The date and time copied into a timestamp label is not modified later if the plot is modified, saved, etc.

3.5.15 Graph -> Add Image (Alt-I)

Opens a file dialog allowing you to select an image to be added to the active plot layer. Only a link to the image file will be savedinto the project file and not the image itself. The new image is added to the left-top corner of the layer and can be moved withthe mouse using drag-and-drop.

3.5.16 Graph -> Add Central Axis

The commands in this menu can be used in order to add central axes, horizontal or vertical, to the active plot layer. The initialposition of an axis is in the center of the plot canvas, but it can be moved either by drag-and-drop with the mouse or using thearrow keys. The axes can be fully customized via their Properties dialog which can be opened with a double-click on the axisarea. Central axes can be removed or hidden via their context menu. A right-click on the axis opens the context menu.

3.5.16.1 Add Horizontal Axis

Adds a central horizontal axis to the active plot layer. The axis can be moved by drag-and-drop with the mouse or using the Upand Down arrow keys.

3.5.16.2 Add Vertical Axis

Adds a central vertical axis to the active plot layer. The axis can be moved by drag-and-drop with the mouse or using the Leftand Right arrow keys.

3.5.17 Z-Order Commands...

The zorder commands act upon the last few items. Even though they do not appear in the graph menu, they are in the plot toolbarand in the object drop down lists when right clicking a selected object.

3.5.17.1 Move to Top

Although this command does not appear in the Graph menu, it does act upon the objects created using the last few commands(specifically legend, equation, text, timestamp, ellipse, rectangle and image objects). When a suitable object is selected, thiscommand will be available, either from the Plot toolbar or from the drop-down list that appears when right-clicking on a selectedobject. When the command is used, the object will be made visible by being promoted to the front of the plot layer. It does notaffect the z-order relative to other objects. Their relative z-order depends only upon their order of creation.

3.5.17.2 Move to Bottom

Although this command does not appear in the Graph menu, it does act upon the objects created using the last few commands(specifically legend, equation, text, timestamp, ellipse, rectangle and image objects). When a suitable object is selected, thiscommand will be available, either from the Plot toolbar or from the drop-down list that appears when right-clicking on a selectedobject. When the command is used, the object will be made invisible by being demoted to the back of the plot layer. It does notaffect the z-order relative to other objects. Their relative z-order depends only upon their order of creation.

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3.5.18 Graph -> Add Layer (Alt-L)

Adds a new layer to a graph window. The command opens a dialog which allows you to select whether the new layer is to beadded to the left-top corner of the plot window or to a best-guess position (based on a layer positioning algorithm in columns androws).

3.5.19 Graph -> Add Empty Inset Layer

This is a convenience command that creates a new, small sized, empty layer located on top of the currently selected layer. Oncethis layer is created, you can further resize, move, set it’s properties and add curves to it as needed. Inset layers are not linkedto another layer in any way. They just happen to be located in the same place on the graph window. In fact the inset layer canbe moved anywhere on the graph window and is treated like a normal layer in every way. When the inset layer is completelycontained inside another layer, it will disappear under that layer when it is selected. The new inset layer has it’s own layer selectbutton in the upper left of the graph window. Clicking on this button will bring the inset back to the front, rendering it visibleagain.

3.5.20 Graph -> Add Inset Layer With Curves

This command is essentially identical to the Add Empty Inset Layer command, with the single exception that any curvescontained in the currently active layer are duplicated in the new inset layer.

3.5.21 Graph -> Arrange Layers... (Shift-A)

Opens the Arrange layers dialog. This dialog allows you to customize the layout of the layers in the active graph window.

3.5.22 Graph -> Automatic Layout command

Automatically arranges all the layers in the active graph window. There must be at least 2 layers on the graph. Layers are packedinto the smallest dimensioned array possible. All layers are scaled to fit into the existing graph window. Rows are added until athe smallest square array is filled, at which point an additional column is added. Rows are then filled and additional rows addeduntil the array is again square. For example, 2 layers results in a 1x2 array. 3 layers produces a 2x2 array with an empty space inthe second row. 4 layers produces a full 2x2 array. Adding another layer will produce a 2x3 array, with one empty space in thesecond row. Additional layers result in more rows and columns being added to contain all the layers.

3.5.23 Graph -> Extract to Layers command

Each curve in the currently active layer is moved onto a newly created layer. The original layer is destroyed. The newly createdlayers are then auto arranged (see the Automatic Layout command).

3.5.24 Graph -> Extract to Graphs... command

Each layer in the currently active graph window is copied into its own, newly created, graph window, which has the same sizeas the source graph window. This command also opens the Graph Manipulation dialog, allowing users to choose what happenswith the original graph window and if the new layers should be resized to fill the whole graph window.

3.5.25 Graph -> Merge Graph Windows... command

Opens the Graph Manipulation dialog in a mode that allows users to choose the graph windows to be merged in a new 2D plotwindow.

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3.5.26 Graph -> Remove Layer (Alt-R)

Deletes the active layer and pops-up a question dialog allowing you to choose whether the remaining layers should be automati-cally re-arranged or not.

3.6 The Plot Menu

This menu is active only when a table is selected. These commands allow plotting data from the selected table. As a group, allof these commands create a new graph window which contains a single, empty layer. The newly created plot is drawn on thisempty layer.

3.6.1 Plot Wizard (Ctrl-Alt-W)

Opens the Plot Wizard dialog.

3.6.2 Line ->

Selecting Line -> opens up a sub-menu of additional commands for plotting specialized graphs consisting of lines.

3.6.2.1 Line

Plots the selected data columns using "Line" style. The command can also be activated by clicking on the icon of the Tabletoolbar. Once the plot is created, the drawing style of the data series can be customized with the Custom curves dialog.

3.6.2.2 Line Central

Plots a graph of the selected data columns using "Line" style and the X and Y axes located in the middle of the layer. Thecommand can also be activated by clicking on the icon of the Table toolbar. Once the plot is created, the drawing style of thedata series can be customized with the Custom curves dialog. The axes can also be customized by opening the correspondingdialog via a double-click on the axis ticks or labels.

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3.6.2.3 Vertical Steps

Plots the selected data columns using "Vertical Steps" style. Once the plot is created, the drawing style of the data series can becustomized with the Custom curves dialog.

3.6.2.4 Horizontal Steps

Plots the selected data columns using "Horizontal Steps" style. Once the plot is created, the drawing style of the data series canbe customized with the Custom curves dialog.

3.6.3 Symbol ->

Selecting Symbol -> opens up a sub-menu of additional commands for plotting specialized graphs using "Scatter" style for thedata.

3.6.3.1 Scatter

Similar to the Line command except that the plot is drawn using "Scatter" style. The command can also be activated by clickingon the icon of the Table toolbar. Once the plot is created, the drawing style of the data series can be customized with the Plotdetails dialog.

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3.6.3.2 Scatter Central

Plots a graph of the selected data columns using "Scatter" style and the X and Y axes located in the middle of the layer. Thecommand can also be activated by clicking on the icon of the Table toolbar. Once the plot is created, the drawing style of thedata series can be customized with the Plot details dialog. The axes can also be customized by opening the corresponding dialogvia a double-click on the axis ticks or labels.

3.6.3.3 Vertical Drop Lines

Plots the selected data columns using "Vertical drop lines" style. The command can also be activated by clicking on the iconof the Table toolbar. Once the plot is created, the drawing style of the data series can be customized with the Plot details dialog.

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3.6.3.4 Bubble

Plots the selected data columns using indexed sizes for the plot symbols. You need to select at least two Y columns for this plotoperation. The first Y column in the selection is used for the positions of the plot symbols and the next one determines theirsizes. The command can also be activated by clicking on the icon of the Table toolbar. Once the plot is created, the drawingstyle of the data series can be customized with the Plot details dialog.

3.6.3.5 Color Mapped

Plots the selected data columns using a default color map for the plot symbols. You need to select at least two Y columns forthis plot operation. The first Y column in the selection is used for the positions of the plot symbols and the next one determinestheir color. QtiPlot finds the minimum and maximum values in the second Y column, creates eight evenly sized ranges of valuesbetween the minimum and maximum values, and then associates a color with each range of values. Each data point color isdetermined by finding the color associated with the second Y column value in the color map.

The command can also be activated by clicking on the icon of the Table toolbar. Once the plot is created, the drawing style ofthe data series can be customized with the Plot details dialog.

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3.6.3.6 Bubble + Color Mapped

Plots the selected data columns using indexed sizes and a default color map for the plot symbols. You need to select at leasttwo Y columns for this plot operation. The first Y column in the selection is used for the positions of the plot symbols and thenext one determines their sizes. If the selection contains three Y columns the third column controls the symbol color: QtiPlotfinds the minimum and maximum values in this Y column, creates eight evenly sized ranges of values between the minimum andmaximum values, and then associates a color with each range of values. Each data point color is determined by finding the colorassociated with the second Y column value in the color map. If the column selection contains only two Y columns the secondcolumn controls both the size and color of the symbols.

The command can also be activated by clicking on the icon of the Table toolbar. Once the plot is created, the drawing style ofthe data series can be customized with the Plot details dialog.

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3.6.4 Line + Symbol ->

3.6.4.1 Line+Symbol

Identical to the Line command except that the plot is drawn using "Line + Symbol" style. This command can also be activatedby clicking on the icon of the Table toolbar. Once the plot is created, the drawing style of the data series can be customizedwith the Custom curves dialog.

3.6.4.2 Line + Symbol Central

Plots a graph of the selected data columns using "Line + Symbol" style and the X and Y axes located in the middle of the layer.The command can also be activated by clicking on the icon of the Table toolbar. Once the plot is created, the drawing style ofthe data series can be customized with the Custom curves dialog. The axes can also be customized by opening the correspondingdialog via a double-click on the axis ticks or labels.

3.6.4.3 Spline

Plots the selected data columns using "Spline" style. Once the plot is created, the drawing style of the data series can becustomized with the Custom curves dialog.

3.6.5 Column/Bar/Pie ->

Selecting Column/Bar/Pie opens up a sub-menu of commands for plotting specialized bar and column graphs.

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3.6.5.1 Columns

Plots the selected data columns using "Columns" style, that is vertical bars.

3.6.5.2 Rows

Plots the selected data columns using "Rows" style.

3.6.5.3 Stack Column

This command can be activated by clicking on the icon of the Table toolbar. The Stack Column command plots a stack-column for each selected row in the currently active table. It is essentially the same as the Stack Bar plot, but drawn as verticalstack-columns rather than horizontal stack-bars.

3.6.5.4 Stack Bar

This command can be activated by clicking on the icon of the Table toolbar. The Stack Bar command plots a stack-bar foreach selected row in the currently active table. They may be used to conveniently display cumulative data that changes overtime, such as budgetary information. The stack-bars are drawn one above the other in a position determined by the X value of thecorresponding row. Each stack-bar is composed of a set of joined segments. The widths of the segments are set by the Y values inthe row and their relative positions correspond to the column order in the table. Each segment is plotted in a color corresponding

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to the column number of the Y value determining the segment’s width. Colors, segment outlining, vertical separation of thestack-bars, and the axis values can all be customized. An example of a stack-bar plot is shown below, followed by the table thatwas used to generate the plot.

A stack-bar plot showing a hypothetical budgetary breakdown for a 5 year period. The data in the table shown below was usedto generate this plot.

3.6.5.5 100% Stack Column

This command can be activated by clicking on the icon of the Table toolbar. The 100% Stack Column command plots astack-column for each selected row in the currently active table. It is essentially the same as the 100% Stack Bar plot, but drawnas vertical stack-columns rather than horizontal stack-bars.

3.6.5.6 100% Stack Bar

This command can be activated by clicking on the icon of the Table toolbar. The 100% Stack Bar command plots a stack-bar for each selected row in the currently active table, comparing the percentage that each value contributes to a total acrosscategories. You can use a 100% stacked bar plot when you have several data sets and you want to emphasize the contributions tothe whole, especially if the total is the same for each category.

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3.6.5.7 Floating Column

This command can be activated by clicking on the icon of the Table toolbar. The floating column graph displays Y values asbeginning and ending column levels for each X value. You must select at least two Y columns of values (or a range from at leasttwo columns). If there is an X column to the left of the Y columns, the X column values are used; otherwise, the worksheet’sdefault X values are used.

3.6.5.8 Floating Bar

This command can be activated by clicking on the icon of the Table toolbar. The floating bar graph displays Y values asbeginning and ending bar levels for each X value. The X values are plotted along the vertical axis. You must select at least twoY columns of values (or a range from at least two columns). If there is an X column to the left of the Y columns, the X columnvalues are used; otherwise, the worksheet’s default X values are used.

3.6.5.9 3D Color Pie Chart

This command can be activated by clicking on the icon of the Table toolbar. Creates a pseudo 3D colored pie chart using theselected column in the active table window (only one column allowed).

3.6.5.10 2D BW Pie Chart

This command can be activated by clicking on the icon of the Table toolbar. Creates a 2D black and white pie chart using theselected column in the active table window (only one column allowed).

3.6.6 Multi-Curve ->

Selecting Multi-Curve -> opens up a sub-menu of additional commands for plotting multiple data sets.

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3.6.6.1 Double-Y

Creates a double Y axis graph. Requires a selection of at least two Y columns (or a range from at least two columns). The last Ycolumn in the selection range is attached to the right axis of the plot layer.

3.6.6.2 3Y: Y-YY

Creates a three Y axes graph. Requires a selection of at least three Y columns (or a range from at least three columns). In orderto display a third Y axis QtiPlot uses two plot layers with overlapping drawing canvases. The right axis of the second plot layeris displayed using a horizontal offset with respect to the drawing canvas. The last data curve created from the selected range isattached to this axis.

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3.6.6.3 4Y: YY-YY

Creates a four Y axes graph. Requires a selection of at least four Y columns (or a range from at least four columns). Twooverlapping layers are created for this type of plot. Both Y axes of the second plot layer are enabled.

3.6.6.4 Stack Lines by Y Offsets

Creates a new graph window containing a Stacked Lines plot generated from data in the selected columns. Each column is drawnas a separate curve which has a vertical offset from the previous one. This offset setting that can be modified in the Stack tab ofthe Plot Details dialog. By default, Stacked Lines by Y Offsets graphs employ the "Auto" data plot offset type, meaning that agap of 8% is automatically calculated between each data plot. The distances between each curve can be adjusted using this offsetfeature to eliminate the need to change the original data. Using this feature prevents the curves from overlapping and ensuresthat each curve can be viewed clearly.

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3.6.6.5 Waterfall

Creates a new graph window containing a waterfall plot generated from data in the selected columns. Each column is drawn asa separate curve which is offset from the previous one in both X and Y, creating the so-called waterfall effect. The figure shownbelow is a simple example of a waterfall plot where each column is simply an attenuated version of the previous column.

3.6.6.6 Colormapped Lines

Requires a selection of at least two Y columns (or a data range from at least two columns). Creates a new graph windowdisplaying each data set as a line curve. Existing column comments are treated as Z values if they are valid floating point values.If there are no valid column comments, the column indices define the Z values. The colors of the curves are mapped to these Zvalues and a color scale legend is added at the right side of the plot layer.

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3.6.7 Area ->

Selecting Area -> opens up a sub-menu of additional commands for generating area graphs.

3.6.7.1 Area

An Area graph is a line graph with the areas below the lines filled with colors. This command can be activated by clicking onthe icon of the Table toolbar. You must select at least one Y column of values (or a range from at least one column). If theY column(s) has an associated X column, the X column supplies the X values; otherwise, the worksheet’s default X values areused.

3.6.7.2 Stack Area

This command can be activated by clicking on the icon of the Table toolbar. In order to create this type of graph you mustselect at least two Y columns of values (or a range from at least two columns). Each successive column of values is displayed asan area graph that is stacked on the previous area graph. The upper bounds of the first area graph is treated as the baseline of thenext area graph.

3.6.7.3 100% Stack Area

This command can be activated by clicking on the icon of the Table toolbar. In order to create this type of graph you mustselect at least two Y columns of values (or a range from at least two columns). 100% Stack Area graphs help comparing thepercentage that each value contributes to a total across categories. You can use them when you have several data sets and youwant to emphasize the contributions to the whole, especially if the total is the same for each category.

3.6.7.4 Fill Area

This command can be activated by clicking on the icon of the Table toolbar. In order to create this type of graph you mustselect at least two Y columns of values (or a range from at least two columns). If there is an X column to the left of the Ycolumns, the X column values are used; otherwise, the worksheet’s default X values are used. The area between the data plots(the two Y columns) is filled using a default blue fill pattern.

3.6.8 Special Line/Symbol ->

3.6.8.1 Vectors XYXY

Creates a vectors plot using the selected columns in the active table window. You must select four columns for this particular typeof plot. The first two columns give the coordinates of the starting points of the vectors, the last two columns give the coordinatesof the end points.

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3.6.8.2 Vectors XYAM

Creates a vectors plot using the selected columns in the active table window. You must select four columns for this particulartype of plot. The first two columns give the coordinates of the starting points of the vectors, the last two columns give the angles(in radians) and magnitudes of the vectors.

3.6.8.3 Zoom

Creates a new graph with 2 layers. The first is a standard plot layer which contains a curve for each selected Y column. Thesecond is a special layer which has 2 components: 1) There is a standard plot layer that shows a portion of the first layer’s surfacein a magnified view; 2) There is a separate graphical window that can be sized and dragged around the first layer to specify theportion of that layer which is shown in the magnified view. The figure below shows a typical zoom plot.

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3.6.9 Statistical Graphs ->

Selecting the Statistical Graphs -> item opens up a sub-menu of commands for plotting various statistical graphs. Statisticalplots do not give a direct drawing of the selected table data. However, a representation of the frequency distribution of theY-values is plotted.

3.6.9.1 Box Plot

Creates a box plot using the selected data columns in the active table window. This type of plot is used to give a graphicalrepresentation of some of the classical parameters of a frequency distribution, such as the mean, the min and max values, theposition of the 95 and 5 percentiles, etc. The choice of the statistical parameters and the graphical parameters can be modifiedwith the Custom curves dialog.

3.6.9.2 Histogram

Creates a frequency histogram of the selected data columns in the active table window. The default binning uses 10 steps betweenthe maximum and the minimum values. In order to customize the histogram double-click on the curve or right-click and select"Properties...". Both actions open the Plot Details dialog. The histogram controls are available on tabs on the right side ofthe dialog box. Binning behavior as well as the display of a distribution curve on the binned data can be customized via theHistogram Data tab.

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Note that this command plots a frequency distribution that is computed from your data. If you want to draw a histogram directlyfrom data values, use the Bars plot instead.

3.6.9.3 Histogram + Probabilities

This command can be activated by clicking on the icon of the Table toolbar. You must select exactly one Y column or a rangefrom a table column. The Histogram + Probabilities creates a frequency histogram of the selected data column in the activetable window, exactly like the Histogram command. Additionally, it plots a cumulative sum of observations in a second graphlayer (layer 2). The statistical results - the mean, the standard deviation, the maximum and minimum values, and the total numberof values - are also displayed to the Results log.

The two layers in the Histogram + Probabilities graph are linked. Therefore, before you make changes to the X axis scale or tothe dimensions of the layer, make sure that the layer 2 is the active layer. This will ensure that the axis scales and dimensions ofthe layer 1 are adjusted accordingly.

3.6.9.4 Stacked Histogram

Creates vertically stacked layers displaying the histograms of the selected data columns in the active table window (one histogramper layer) See the Vertical 2 Layers command for more details.

3.6.9.5 Stem and Leaf

Generates a stem-and-leaf tabular plot from the selected column in a new note window. Stem-and-Leaf plots are similar tohistograms but are represented using rows of decimal digits. Like a histogram, data is binned, usually by taking the mostsignificant digits (MSDs) as "stem" values which are listed in a column on the left. The least significant digit(s) from all valueshaving identical MSDs are then listed to the right of each stem value. From a statistical point of view, this gives the appearanceof a histogram but preserves the actual data values in the plot. When this command is executed, you will be given the opportunityto select/confirm the binning increment, which is given as a power of 10 and defaults to a power of 1 (that is, a binning incrementof 10).

This figure shows a typical stem-and-leaf representation of 48 random data points which are roughly Gaussian (i.e., normallydistributed) and uses the default binning increment of 10.

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3.6.10 Panel ->

Selecting the Plot -> Panel -> menu item opens a sub-menu of commands that can be used to quickly obtain some commonlyused arrangements of multiple plots. Unlike other commands in this menu, the new graph window that is created may have morethan one layer (as needed).

3.6.10.1 Vertical 2 Layers

Creates 2 vertically stacked layers. The data columns selected in the active table window (one curve per layer) are plotted onthese layers.

3.6.10.2 Horizontal 2 Layers

Creates 2 horizontally stacked layers. The data columns selected in the active table window (one curve per layer) are plotted onthese layers.

3.6.10.3 4 Layers

Creates 4 layers on a 2x2 grid. The data columns selected in the active table window (one curve per layer) are plotted on theselayers.

3.6.10.4 Stacked Layers

Creates a group of vertically stacked layers, one layer per Y-Coordinate column selected. Data columns selected in the activetable window (one curve per layer) are plotted on these layers.

3.6.10.5 Custom Layout...

Opens the Arrange Layers dialog which allows complete customization of the layer layout.

3.6.11 Data -> Plot 3D ->

Selecting the Plot -> Plot 3D -> menu item opens a sub-menu of commands used to draw some common 3D plots of 2D data.

3.6.11.1 Ribbons

Makes a 3D plot of the selected data column in the active table window (only one column allowed) using "Ribbon" style.

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3.6.11.2 Bars

Makes a 3D plot of the selected data column in the active table window (only one column allowed) using "3D Bars" style.

3.6.11.3 Scatter

Makes a 3D plot of the selected data column in the active table window (only one column allowed) using "3D Dots" style. The3D point symbol style can be changed via the 3D Plots Settings dialog.

With scatter plots, you can choose the kind of graphic item which is used to plot the data points. The example above is done withcross hairs, but you can also select points or cones. This can be done either with the corresponding icons of the 3D plot toolbar(respectively and for cross-hairs, dots and cones) or with the custom-curves dialog.

3.6.11.4 Trajectory

Makes a 3D plot of the selected data column in the active table window (only one column allowed) using "3D Line" style. Theline width and color may be changed via the 3D Plots Settings dialog.

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3.7 The 3D Plot menu

This menu is only active (visible) when a matrix is selected.

3.7.1 3D Wire Frame

Makes a 3D plot of the selected matrix using the "3D mesh" style.

3.7.2 3D Hidden Lines

Makes a 3D plot of the matrix using the "3D mesh" style with hidden lines.

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3.7.3 3D Polygons

Makes a 3D plot of the matrix using the "3D polygons" style.

3.7.4 3D Wire Surface

Makes a 3D plot of the matrix using the "3D polygons" style with the mesh drawn.

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3.7.5 Bars

Makes a 3D plot of the selected data column in the active table window (only one column allowed) using the "3D Bars" style.

3.7.6 Scatter

Makes a 3D plot of the selected data column in the active table window (only one column allowed) using the "3D Dots" style.The 3D point symbol style can be changed via the 3D Plots Settings dialog.

3.7.7 Contour+Color Fill

Makes a color map plot of the data in the active matrix window. The contour lines and the colormap settings may be changed byclicking on the plotting area. This will activate the Contour Options Dialog.

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3.7.8 Countour Lines

Makes a contour plot of the data in the active matrix window. The contour lines and the colormap settings may be changed byclicking on the plotting area. This will activate the Contour Options Dialog.

3.7.9 Gray Scale Map

Makes a gray map plot of the data in the active matrix window. The contour lines and the colormap settings may be changed byclicking on the plotting area. This will activate the Contour Options Dialog.

3.8 The Data Menu

This menu is visible and active only when a graph window is selected. Commands in this menu will act on the plot/layer that iscurrently active in the graph window. All of these commands are switches - that is, they switch on an operational mode which

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remains in effect until it is canceled by selecting another command or by using the Disable tools command.

3.8.1 Data -> Disable tools

For many of the remaining commands in this menu, QtiPlot will be locked into a special mode corresponding to that command,and that command’s special pointer will be used instead of the normal pointer. This command is used to exit any of these specialmodes, returning QtiPlot to its normal mode and pointer behavior.

3.8.2 Data -> Zoom In/Out and Drag Canvas

Switches the active plot layer into a dynamic zoom/drag mode. Upon command execution, the default mode is "dynamic drag".To drag the plot, simply left click anywhere in the plotting area and drag the plot around with the mouse. Drop it at the newlocation by releasing the left mouse button. To zoom the plot, switch to dynamic zoom mode by first right clicking somewherein the plot area. (This will probably pop-up a context menu that you should ignore.) Next, left click at a suitable zoom referencepoint in the plot area to enter dynamic zoom mode (this will also dismiss any pop-up menu). Once in dynamic zoom mode, scalethe plot by moving the mouse cursor up to zoom out, or down to zoom in. Right and left mouse movements have no effect. Youshould use some foresight in picking the zoom reference point. For example, selecting a point at the bottom of the plot area willlimit zooming to upward mouse travel - that is, you will only be able to zoom out. Once a suitable zoom factor has been found,left click anywhere in the plot to accept the zoom and return to dynamic drag mode.

Note that the mouse wheel is always active when using this command. It can be used to zoom while in either dynamic drag ordynamic zoom modes. Also note that in either mode, zooming leaves the plot’s aspect ratio unchanged.

3.8.3 Data -> Zoom/Drag Canvas Horizontally

Switches the active plot layer into a dynamic zoom/drag mode which is limited to the horizontal direction. Upon commandexecution, the default mode is "dynamic horizontal drag". To drag the plot, simply left click anywhere in the plotting area anddrag the plot to the right or left with the mouse. Drop it at the new location by releasing the left mouse button. Note that it mayappear that you can move the plot up or down while dragging, but the original vertical location will be restored when the plotis dropped at the new horizontal location. To zoom the plot, switch to dynamic horizontal zoom mode by first right clickingsomewhere in the plot area. (This will probably pop-up a context menu that you should ignore.) Next, left click at a suitablezoom reference point in the plot area to enter dynamic horizontal zoom mode (this will also dismiss any pop-up menu). Once indynamic horizontal zoom mode, scale the plot’s width by moving the mouse cursor up to zoom out, or down to zoom in. Rightand left mouse movements have no effect. You should use some foresight in picking the zoom reference point. For example,selecting a point at the bottom of the plot area will limit zooming to upward mouse travel - that is, you will only be able tozoom out. Once a suitable zoom factor has been found, left click anywhere in the plot to accept the zoom and return to dynamichorizontal drag mode.

Note that the mouse wheel is always active when using this command. It can be used to zoom while in either dynamic horizontaldrag or dynamic horizontal zoom modes. Also note that in either horizontal mode, zooming will change the plot’s aspect ratio.

3.8.4 Data -> Zoom/Drag Canvas Vertically

Switches the active plot layer into a dynamic zoom/drag mode which is limited to the vertical direction. Upon command execu-tion, the default mode is "dynamic vertical drag". To drag the plot, simply left click anywhere in the plotting area and drag theplot up or down with the mouse. Drop it at the new location by releasing the left mouse button. Note that it may appear that youcan move the plot right or left while dragging, but the original horizontal location will be restored when the plot is dropped atthe new vertical location. To zoom the plot, switch to dynamic vertical zoom mode by first right clicking somewhere in the plotarea. (This will probably pop-up a context menu that you should ignore.) Next, left click at a suitable zoom reference point in theplot area to enter dynamic vertical zoom mode (this will also dismiss any pop-up menu). Once in dynamic vertical zoom mode,scale the plot’s height by moving the mouse cursor up to zoom out, or down to zoom in. Right and left mouse movements haveno effect. You should use some foresight in picking the zoom reference point. For example, selecting a point at the bottom of theplot area will limit zooming to upward mouse travel - that is, you will only be able to zoom out. Once a suitable zoom factor hasbeen found, left click anywhere in the plot to accept the zoom and return to dynamic vertical drag mode.

Note that the mouse wheel is always active when using this command. It can be used to zoom while in either dynamic verticaldrag or dynamic vertical zoom modes. Also note that in either vertical mode, zooming will change the plot’s aspect ratio.

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3.8.5 Data -> Zoom in (Ctrl-+)

Switches the active plot layer to zoom mode. The mouse cursor shape changes to a magnifying lens when it is inside a plotcanvas. To zoom the plot, draw a box around a selected part of the plot by clicking at one corner of the desired box, dragging themouse pointer to the opposite corner of the box and clicking a second time. The plot will be zoomed up such that the contents ofthe drawn box now fills the existing plotting area.

3.8.6 Data -> Zoom out (Ctrl--)

This command cancels a previous zoom operation. A zoom history is kept so that you can do multiple zoom out commands tostep backwards through the zoom history. A separate zoom history is maintained for each plot layer. Executing this commanddoes not set any special mode of its own but it will cancel any other special mode that is currently in effect (i.e., it performs animplicit Disable tools command).

3.8.7 Data -> Select Data Range (Alt-S)

Shows two vertical line cursors that are used for selecting a data range when performing analysis operations. Only one cursoris active at a time. The active cursor is red, the other is black. You change which cursor is active with the Left and Right arrowkeys. Move the active cursor with the arrows keys while keeping the Ctrl key pressed or, more easily and quickly, by clickingon a curve point. Note that the mouse cursor shape changes to a rectangular target while inside the active plot canvas. Navigatethrough the curves on the plot layer using the Up and Down arrow keys. When this tool is active you can easily copy, paste orcut the whole selected data range using the well-known shortcuts: Ctrl+C, Ctrl+V and Ctrl+X, respectively.

3.8.8 Data -> Data Reader (Ctrl-D)

Shows a red cross cursor and opens the Data Display toolbar giving easy and quick access to the values of the data points. Selectdata points by moving the cursor with the Left and Right arrow keys or, more easily and quickly, by clicking on them with themouse. Navigate through the curves on the plot layer with the Up and Down arrow keys. The [Home] key makes the data readerjump to the beginning of the selected curve and the [End] key to its end point.

3.8.9 Data -> Annotation

Opens the Data Display toolbar and changes the mouse cursor shape to a small cross target. The coordinates of the cursor withrespect to the axes of the active plot layer are displayed in a text field that floats along with the mouse cursor. Clicking the leftmouse button at any data point of a plot curve will draw a red crosshair at that point and copy the x and y coordinates of thatpoint into the data display. A double-click or pressing the [Enter] key adds an annotation to the plot. Pressing the [TAB] keytoggles the annotation form. Available label forms are:

1. x: Use the X coordinates of the data point as label.

2. y: Use the Y coordinates of the data point as label.

3. i: Use the table row index of the data point as label.

4. (x,y): Use the X and Y coordinates of the data point as label.

5. (x,y)[i]: Use the X and Y coordinates and the table row index of the data point as label.

3.8.10 Data -> Screen Reader

Opens the Data Display toolbar and changes the mouse cursor shape to a small cross target. The coordinates of the cursor withrespect to the axes of the active plot layer are displayed in a text field that floats along with the mouse cursor. Clicking the leftmouse button at any point will draw a red crosshair at that point and copy the x and y coordinates of that point into the datadisplay.

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3.8.11 Data -> Draw Data Points

This command is very similar to the Screen Reader command but with the addition of the ability to add data points to a plot bydouble clicking at each of the desired points. Each invocation of this command will create a new table titled "DrawN", whereN is an integer number that is incremented after each new table addition. These tables can be renamed and reformatted aftercreation using the standard window manipulation commands.

3.8.12 Data -> Move Data points (Ctrl-Alt-M)

Allows modification of the position of data points on the active plot layer by simple drag-and-drop. Precise positioning of thedata points can be done using the numeric keypad which define a sort of compass rose:

1. 8-key: North

2. 9-key: North-East

3. 6-key: East

4. 3-key: South-East

5. 2-key: South

6. 1-key: South-West

7. 4-key: West

8. 7-key: North-West

When selecting this command, you will be asked to confirm that you understand that any changes you make will automaticallymodify the data in the corresponding tables (as well as all plots depending on that data). The coordinates of the cursor withrespect to the axes of the plot layer are displayed in a text field that floats along with the mouse cursor. However, the DataDisplay toolbar is also opened to provide a higher resolution display the new coordinates.

3.8.13 Data -> Remove Bad Data Points (Alt-B)

Allows removal of data points from the active plot layer by double-clicking on them. When selecting this command, you will beasked to confirm that you understand that any changes you make will also modify the data in the corresponding tables (as wellas all plots depending on that data). The coordinates of the cursor with respect to the axes of the plot layer are displayed in a textfield that floats along with the mouse cursor. The coordinates of all points selected for removal are shown in the Data Displaytoolbar.

3.8.14 Data -> Remove Bad Data Points

Allows dragging an entire curve on the selected plot layer. Left Click and hold down the mouse button on any point on a curve toselect the curve for dragging. A red cross-hair will be drawn at the point to indicate that the curve is selected. The curve may thenbe dragged around on the plot layer with the mouse as long as the left mouse button is held down. Releasing the mouse buttonwill drop the curve at the new location. This process moves all the data points and changes the coordinates in the associatedtable. When selecting this command, you will be asked to confirm that you understand that dragging curves will modify the datain the corresponding tables (as well as all other plots depending on that data). The coordinates of the cursor with respect to theaxes of the plot layer are displayed in a text field that floats along with the mouse cursor.

3.9 The Analysis Menu

The commands available in this menu change depending upon whether a table, a matrix or a plot is selected.

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3.9.1 Commands for the analysis of data in tables

3.9.1.1 Descriptive Statistics

3.9.1.1.1 Statistics on Columns

The Analysis -> Descriptive Statistics -> Statistics on Columns command creates a new table providing basic statistical infor-mation about the selected columns in the active table: average, variance, standard deviation, max value, etc...

If you select several columns in one table, one line of statistical information will be created for each selected column. However,you can not select columns from different tables and obtain one single table of statistics.

It is possible to edit in place the names of the columns and the range of rows to be analysed by double-clicking the correspongingcells. However, you can not set different row ranges for different columns. A valid range of rows must be entered in the Rowscolumn, under the form [startRow:endRow], whith startRow lower than endRow. Entering the value -1 for the endRow meansthe whole column.

3.9.1.1.2 Statistics on Rows

The Analysis -> Descriptive Statistics -> Statistics on Rows command creates a new table providing basic statistical informationabout the selected rows in the active table: average, variance, standard deviation, max value, etc. Statistics are calculated only onnumeric data in visible columns. Usually, statistics should be calculated on data of a similar type - Y values for example. Thisfeature permits selection of only those columns that should be included in the statistical calculation.

It is possible to edit in place the index of the rows to be analysed by double-clicking the corresponging cells.

3.9.1.1.3 Frequency Count

The Analysis -> Descriptive Statistics -> Frequency Count command calculates the frequency distribution of the data in theselected column. The Frequency Count dialog is popped up which allows selecting the data range and the bin width. If morethan one column is selected, an error dialog will pop-up.

3.9.1.1.4 Normality Test

The Analysis -> Descriptive Statistics -> Normality Test command computes a Shapiro-Wilk test on the selected column todetermine how well the column conforms to a normal distribution. For a detailed discussion of this topic, see the Wikipediaarticle on Normality Testing.

3.9.1.2 Hypothesis-Testing

3.9.1.2.1 One Sample t-Test

The Analysis -> Hypothesis Testing -> One Sample t-Test command performs a Student’s t-test on a the selected column of datato estimate the statistical likelihood that the mean has a specific value. It is assumed that the data are normally distributed. Theresults of the test are placed in the Results log. The Wikipedia article on the Student’s t-test makes for excellent reading on thistopic.

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3.9.1.2.2 Two Sample t-Test

The Analysis -> Hypothesis Testing -> Two Sample t-Test command performs a Student’s t-test on two selected columns of datato estimate the statistical likelihood that the means are the same. The results of the test are placed in the Results Log. See theWikipedia article on the Student’s t-test for more information.

3.9.1.3 ANOVA

3.9.1.3.1 One-Way ANOVA

The Analysis -> ANOVA -> One-Way ANOVA command performs a One-way analysis of variance on a the selected column ofdata. The results of the test are placed in the Results Log. The Wikipedia article on the One-way ANOVA for a more detaileddiscussion.

3.9.1.3.2 Two-Way ANOVA

The Analysis -> ANOVA -> Two-Way ANOVA command performs a Two-way analysis of variance on a the selected columnsof data. The results of the test are placed in the Results Log. See the Wikipedia article on the Analysis of Variance for moredetails about this topic.

3.9.1.4 Sort Column

The commands in this menu can be used to sort the selected column(s).

3.9.1.4.1 Ascending

The Analysis -> Sort Column -> Ascending command sorts the selected column or columns in ascending order. If the selectioncontains more than one column they are sorted independently.

3.9.1.4.2 Descending

The Analysis -> Sort Column -> Descending command sorts the selected column or columns in descending order. If the selectioncontains more than one column they are sorted independently.

3.9.1.4.3 Custom...

The Analysis -> Sort Column -> Custom... command becomes available if there are more than one column selected. Thiscommand opens the Sorting Options dialog. In this dialog you have the option to sort the selected columns:

• separately: each column will be sorted independently in ascending or descending order

• together: the column selected as the leading column will be sorted into ascending or descending order. The other selectedcolumns will be sorted so as to keep the rows unchanged.

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3.9.1.5 Sort Table

The Analysis -> Sort Table command opens the Sorting Options dialog. It functions in the the same manner as the Custom...command, except that it operates on all columns of the active table.

3.9.1.6 Normalize

These commands are used to normalize data in tables. In this case, normalization is the process of dividing each entry inthe column by the column’s maximum positive value, making the maximum range value equal to 1. Data is not re-centeredso negative values will remain negative and the minimum value may be less than -1. Columns are normalized separately.The command does not create new columns for the normalized data but replaces the values in the selected columns with theirnormalized values. There are 2 variants of this command:

3.9.1.6.1 Normalize -> Columns

The Analysis -> Normalize -> Normalize -> Columns command normalizes only the selected column or columns. If you wantthe normalized data in a new column, use the Add Column command to create a new column, fill it using a "copy/paste" sequenceand then normalize the new column.

3.9.1.6.2 Normalize -> Table

The Analysis -> Normalize -> Normalize -> Table command normalizes all the columns of the table. It is not a global normal-ization of all values of the table: each column is normalized separately.

3.9.1.7 Differentiate

The Analysis -> Differentiate command computes the derivative of the selected Y columns using centered finite differences. Anew plot is created displaying the result of the numerical differentiation. This command creates a new (hidden) table that containsone column of X-values and one column of derivatives of the Y-values.

3.9.1.8 Integrate...

The Analysis -> Integrate... command computes the integral of the selected Y column using the trapezoidal rule. This commandopens the Integration Options dialog that allows to specify the data range to be integrated.

3.9.1.9 FFT...

The Analysis -> FFT... command computes a direct or inverse Fast Fourier Transform. The parameters used can be set with theFFT dialog. See the fft section of the Analysis chapter for more details.

3.9.1.10 Correlate

The Analysis -> Correlate command computes the cross-correlation of the two selected columns. See the correlate section ofthe Analysis chapter for more details.

3.9.1.11 Autocorrelate

The Analysis -> Autocorrelate command computes the cross-correlation of the selected column with itself (auto-correlation).See the correlate section of the Analysis chapter for more details.

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3.9.1.12 Convolute

Does a convolution of two selected columns. The first one being the response and the second the signal. See the convolutionsection of the Analysis chapter for more details.

3.9.1.13 Deconvolute

The Analysis -> Deconvolute command computes the deconvolution of two selected columns. The first one being the responseand the second the signal. See the deconvolution section of the Analysis chapter for more details.

3.9.1.14 Fit Wizard... (Ctrl-Y)

Opens the Non-linear Fit dialog, allowing you to choose the curve to fit, the algorithm and tolerance to use, and the number ofiterations to be performed. You also enter the analytical function, the names of the fitting parameters and their initial (guessed)values. See the Non Linear Curve Fit section of the Analysis chapter for more details.

3.9.2 Commands for the analysis of curves in plots

The following items are enabled only if the active window is a 2D Multilayer Plot Window. If the active plot layer contains morethan one curve, and the Data Range Selectors are not enabled, a dialog window will pop-up allowing you to select the curve youwant to analyze.

In most cases (except for integration), a new red curve is added to the active plot layer and a new table containing the data usedto plot this curve is added to the workspace. Useful information about the operation performed will be shown in the Results Logdisplay.

The commands for theFFT... and Fit Wizard... are presented in the Table Analysis Menu.

3.9.2.1 Translate

This next group of are 2 commands are used for translating curves horizontally and vertically.

3.9.2.1.1 Vertical

The Analysis -> Translate -> Vertical command is used to move a curve in the vertical direction. When the command is selected,the cursor changes to a box and cross with an X-Y coordinate display which floats along with the cursor. You then select 2 points.The first must be a point on a curve. When the first points is selected, a crosshair will be drawn to indicate it’s location. Thesecond point can then be selected anywhere in the active graph region. The vertical distance between the selected points will becalculated, and the selected curve will be translated by this amount. The net result is to place the selected graph point at the newvertical location. Horizontal distance is ignored. This allows selection of the second point at one of the vertical axes, facilitatingalignment of the selected graph point with some value on that axis. The second point may also be another curve point (either onthe same or a different curve), a feature which makes it easy to align two or more curves in the vertical direction. Warning: theunderlying curve’s data is modified by this operation. No other warning will be given.

3.9.2.1.2 Horizontal

The Analysis -> Translate -> Horizontal command is used to move a curve in the horizontal direction. When the command isselected, the cursor changes to a box and cross with an X-Y coordinate display which floats along with the cursor. You then select2 points. The first must be a point on a curve. When the first points is selected, a crosshair will be drawn to indicate it’s location.The second point then can be selected anywhere on the active graph region. The horizontal distance between the selected pointswill be calculated, and the curve will be translated horizontally by this amount. The net result is to place the selected graphpoint at the new location. Vertical distance is ignored. This allows selection of the second point at one of the horizontal axes,facilitating alignment of the selected graph point with some value on that axis. The second point may also be another curve point(either on the same or a different curve), a feature which makes it easy to align two or more curves in the horizontal direction.Warning: the underlying curve’s data is modified by this operation. No other warning will be given.

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3.9.2.2 Subtract

The Subtract group is also used to translate curves, however, in these cases, some functional relationship is used.

3.9.2.2.1 Subtract -> Baseline

The Analysis Subtract -> Baseline command opens the Baseline dialog.

3.9.2.2.2 Subtract -> Reference Data

The Analysis Subtract -> Reference Data command opens the Math on Data Sets dialog.

3.9.2.2.3 Subtract -> Straight Line

The Analysis Subtract -> Straight Line command operates in a manner similar to the Analysis -> Subtract -> Baseline com-mand. However, in this case, the two points which are selected define the end-points of a straight line which is subtracted fromall the curves on the layer.The cursor changes to a cross target with an X-Y coordinate display which floats along with the cursor,similar to that used in the Analysis -> Subtract -> Baseline command. When the first point is selected, it will be marked with asmall circle and crosshairs. As soon as the second point is selected, the line between the two points will be subtracted from thecurves. Warning: the underlying curves’ data is modified by this operation. No other warning will be given.

3.9.2.3 Peaks...

The Analysis -> Peaks... command opens the Find Peaks dialog.

3.9.2.4 Differentiate

The Analysis -> Differentiate command creates a new plot displaying the resulting curve of the numerical differentiation. Thecomputation of the derivative is done by centered finite differences. A new table is created which contains one column forX-values and one column for derivatives of Y-values. It also creates a new plot of the derivative.

3.9.2.5 Integrate...

The Analysis -> Integrate... command performs a piecewise numerical integration of a curve on the selected layer. Curves areintegrated using the trapezoidal rule. There must be at least one curve on the plot layer. This command opens the IntegrationOptions dialog that allows to specify the data range to be integrated.

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3.9.2.6 Integrate Function...

The Analysis -> Integrate Function... command provides the capability of performing the numerical integration of a user definedfunction. The Integrate Function dialog is opened when this command is executed. This dialog provides for the definition ofthe function, the variable of integration, and the parameters that control the integration. Integration is performed using theQAGS algorithm from the GNU Scientific Library. For many functions, all you need do is set the limits of integration and clickthe "Integrate" button. The default values for the other parameters will usually produce excellent results. For some functions,especially those containing singularities and discontinuities, you may need to experiment with the number of sub-intervals andthe tolerance limit to obtain acceptable results. However, a detailed discussion of the use of these 2 parameters is beyond thescope of this manual. If the Plot Area option is checked, a curve of the integrated function will be added to the currently activelayer. In any case, an entry is made in the Log Panel which contains the numerical result of the computed definite integral overthe specified interval.

3.9.2.7 Smooth

There are 4 variants of the Smooth menu item:

3.9.2.7.1 Savitski-Golay...

The Analysis -> Smooth -> Savitsky-Golay... command performs a smoothing of the selected curve using the Savitzky-Golaymethod. The formula used to smooth the curve defined by the points yi=f(xi) is:

The fi values are computed by fitting the data points to a polynomial. They depend on the number of points used for the smoothingof the curve and the order of the polynomial. Compared to the moving window average method, the advantage of this smoothingmethod is that the values of extrema are not truncated. The dialog allows specification of the curve which will be smoothed, theorder of the polynomial, the number of data points used for the polynomial fit before and after each point, and the color used todraw the smoothed curved. A new table will be created to store the data points xi, zi.

Figure 3.1: The Smooth -> Savitsky-Golay... dialog.

3.9.2.7.2 Moving Window Average...

The Analysis -> Smooth -> Moving Window Average... command performs a smoothing of the selected curve with the movingwindow average method. The formula used to smooth the curve defined by the points yi=f(xi) is:

The greater the number of points, n, the smoother the resulting curve zi=f(xi) will be. The dialog allows specification of the curvewhich will be smoothed, the value of n and the color used to draw the smoothed curve. A new table will be created to store thedata points xi, zi.

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Figure 3.2: The Smooth -> Moving Window Average... dialog.

3.9.2.7.3 Lowess...

The Analysis -> Smooth -> Lowess... command performs a smoothing of the selected curve using the Lowess (aka Loess)algorithm. It provides a robust locally weighted regression and is well suited to smooth data for which no formal model exists.

The parameter f is the fraction of points which define the local neighborhood. A value of 0.2 uses 20% of the curve total pointsas neighbors for each data point (+/- 10%). Values of f closer to 1 yield smoother curves. The iterations parameter specifiesthe number of times to run the algorithm runs over the entire data set, each time refining the local weights. In most cases, twoiterations will be sufficient.

Figure 3.3: The Smooth -> Lowess... dialog.

3.9.2.7.4 FFT Filter...

The Analysis -> Smooth -> FFT Filter... command performs a smoothing of the selected curve using the Low Pass method. Thenumber of points specified is used to calculate a cut-off frequency. The dialog also allows specification of the curve which willbe smoothed and the color used to draw the smoothed curve. A new table will be created to store the data points of the smoothedcurve.

Figure 3.4: The Smooth -> FFT Filter... dialog.

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3.9.2.8 FFT Filter

The Analysis -> FFT Filter menu item provides Lowpass, Highpass, Bandpass and Bandreject filter topologies:

3.9.2.8.1 Low Pass...

The Analysis -> FFT Filter -> Low Pass... command uses an FFT based digital filter to attenuate the high frequencies presentin an input signal. See the filtering section for more details. This command opens the FFT Filter Dialog with the filter type set toLow Pass FFT Filter. In this dialog you can select the curve (input signal) to filter and the cut-off frequency of the filter.

Figure 3.5: The FFT Filter -> Low Pass... dialog.

This command creates a new table containing the filtered data, and adds a new curve to the current layer. The curve is a plot ofthe filtered data.

3.9.2.8.2 High Pass...

The Analysis -> FFT Filter -> High Pass... command uses an FFT based digital filter to attenuate the low frequencies presentin an input signal. See the filtering section for more details. This command opens the FFT Filter Dialog with the filter type set toHigh Pass FFT Filter. In this dialog you can select the curve to filter and the cut-off frequency of the filter.

Figure 3.6: The FFT Filter -> High Pass... dialog.

This command creates a new table containing the filtered data, and adds a new curve to the current layer. The curve is a plot ofthe filtered data.

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3.9.2.8.3 Band Pass...

The Analysis -> FFT Filter -> Band Pass... command uses an FFT based digital filter to attenuate both high and low frequenciespresent in an input signal. See the filtering section for more details. This command opens the FFT Filter Dialog with the filtertype set to Band Pass FFT Filter. In this dialog you can select the curve to filter and both the low and high cutoff frequencies ofthe filter.

Figure 3.7: The FFT Filter -> Band Pass... dialog.

This command creates a new table containing the filtered data, and adds a new curve to the current layer. The curve is a plot ofthe filtered data.

3.9.2.8.4 Band Block...

The Analysis -> FFT Filter -> Band Pass... command uses an FFT based digital filter to remove a band of frequencies from asignal while leaving those frequencies above and below the stop band. See the filtering section for more details. This commandopens the FFT Filter Dialog with the filter type set to Band Block FFT Filter. In this dialog you can select the curve to filter andboth the lower and upper stop-band frequencies of the filter.

Figure 3.8: The FFT Filter -> Band Block... dialog.

This command creates a new table containing the filtered data, and adds a new curve to the current layer. The curve is a plot ofthe filtered data.

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3.9.2.9 Interpolate...

The Analysis -> Interpolate... command performs an interpolation using the selected method. The curve must have enough datapoints to compute interpolated points, if not a warning message will be popped up.

The available interpolation methods are Linear (the curve must contain at least 3 points), Cubic Spline (the curve you analyzemust contain at least 4 points), Non-rounded Akime spline (the curve you analyze must contain at least 5 points). See the Analysischapter for a comparison of the different methods.

Figure 3.9: The Interpolate... dialog.

This command creates a new curve on the current layer, and a new table.

3.9.2.10 FFT...

The Analysis -> FFT... command performs a forward or inverse FFT of the selected curve. The parameters used can be set withthe FFT dialog.

The inverse FFT transform of a forward transform will result in a data set identical to that used for the forward transform.

3.9.2.11 Fit Linear

The Analysis -> Fit Linear command performs a linear fit of the selected curve. The results will be given in the Log panel

3.9.2.12 Fit Polynomial...

The Analysis -> Fit Polynomial... command opens the Polynomial Fit Options dialog, allowing you to choose the curve to fit,the order of the polynomial function to use, the number of points of the resulting curve and the abscissa limits for the fit.

3.9.2.13 Fit Exponential Decay

Analysis -> Fit Exponential Decay provides 3 forms of exponential decay:

3.9.2.13.1 First Order...

The Analysis -> Fit Exponential Decay -> First Order... opens the Exponential Fit dialog, allowing you to choose the curve tofit and the initial guesses for the fit parameters.

3.9.2.13.2 Second Order...

The Analysis -> Fit Exponential Decay -> Second Order... opens a dialog, allowing you to choose the curve to fit and the initialguesses for the fit parameters.

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3.9.2.13.3 Third Order...

The Analysis -> Fit Exponential Decay -> Third Order... opens a dialog, allowing you to choose the curve to fit and the initialguesses for the fit parameters.

3.9.2.14 Fit Exponential Growth...

Analysis -> Fit Exponential Growth... performs an exponential growth fit to the selected curve.

3.9.2.15 Fit Boltzmann (sigmoidal)

The Analysis -> Fit Boltzmann (sigmoidal) performs a fit to a Boltzmann function on the selected curve. It can be used toobtain the correlation equation of an S shaped data set.

3.9.2.16 Fit Pseudo-Voigt

Analysis -> Fit Pseudo-Voigt provides two forms of Pseudo-Voigt profile:

3.9.2.16.1 PsdVoigt1...

The Analysis -> Fit Pseudo-Voigt -> PsdVoigt1... performs a fit to a PsdVoigt1 function on the selected curve.

3.9.2.16.2 PsdVoigt2...

The Analysis -> Fit Pseudo-Voigt -> PsdVoigt2... performs a fit to a PsdVoigt2 function on the selected curve.

3.9.2.17 Fit Gaussian

The Analysis -> Fit Gaussian performs a Gaussian fit to the selected curve. It can be used to obtain the correlation equation ofa bell shaped data set.

3.9.2.18 Fit Lorentzian

Analysis -> Fit Lorentzian performs a Lorentzian fit to the selected curve. It can be used to obtain the correlation equation of abell shaped data set.

3.9.2.19 Fit Multi-peak

Analysis -> Fit Multi-peak performs a fit to a sum of profile functions on the selected curve. Four different profiles are available:

3.9.2.19.1 Gaussian...

Analysis -> Fit Multi-peak -> Gaussian... performs a fit to a sum of N Gaussian functions on the selected curve.

3.9.2.19.2 Lorentzian...

Analysis -> Fit Multi-peak -> Lorentzian... performs a fit to a sum of N Lorentzian functions on the selected curve.

3.9.2.19.3 PsdVoigt1...

Analysis -> Fit Multi-peak -> PsdVoigt1... performs a fit to a sum of N Pseudo-Voigt functions on the selected curve.

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3.9.2.19.4 PsdVoigt2...

Analysis -> Fit Multi-peak -> PsdVoigt2... performs a fit to a sum of N Pseudo-Voigt functions on the selected curve.

3.9.3 Commands for the analysis of data in matrices

The following items are enabled only if the active window is a matrix window.

3.9.3.1 Integrate

The Analysis -> Integrate command computes the integral of the selected matrix using the trapezoidal rule. The result will bedisplayed in the Log panel.

3.9.3.2 FFT...

The Analysis -> FFT... command computes a direct or inverse two dimensional Fast Fourier Transform. The parameters usedcan be set with the FFT dialog. See the FFT section of the Analysis chapter for more details.

3.9.3.3 Forward FFT

The Analysis -> Forward FFT command computes a direct two dimensional Fast Fourier Transform. Please beware that theinput matrix will be modified in order to store the amplitudes of the 2D FFT operation.

3.9.3.4 Inverse FFT

The Analysis -> Inverse FFT command computes an inverse two dimensional Fast Fourier Transform. Please beware that theinput matrix will be modified in order to store the amplitudes of the 2D FFT operation.

3.9.3.5 FFT Filter

The Analysis -> FFT Filter menu item provides Lowpass, Highpass, Bandpass and Bandreject filters. QtiPlot uses the twodimensional FFT method explained in the following article by Paul Bourke: http://paulbourke.net/miscellaneous/dft/.

3.9.3.5.1 Low Pass...

The Analysis -> FFT Filter -> Low Pass... command uses a two dimensional FFT based digital filter to attenuate the highfrequencies present in an input matrix, see the following article by Paul Bourke http://paulbourke.net/miscellaneous/imagefilter/for more details. This command opens the FFT Filter Dialog with the filter type set to Low Pass FFT Filter. In this dialog youcan select the matrix to filter and the cut-off frequency of the filter. The input matrix will be modified in order to store the filtereddata.

3.9.3.5.2 High Pass...

The Analysis -> FFT Filter -> High Pass... command uses a 2D FFT based digital filter to attenuate the low frequencies presentin an input matrix, see the following article by Paul Bourke http://paulbourke.net/miscellaneous/imagefilter/ for more details.This command opens the FFT Filter Dialog with the filter type set to High Pass FFT Filter. In this dialog you can select thematrix to filter and the cut-off frequency of the filter. The input matrix will be modified in order to store the filtered data.

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3.9.3.5.3 Band Pass...

The Analysis -> FFT Filter -> Band Pass... command uses a 2D FFT based digital filter to attenuate both high and lowfrequencies present in an input signal, see the following article by Paul Bourke http://paulbourke.net/miscellaneous/imagefilter/for more details. This command opens the FFT Filter Dialog with the filter type set to Band Pass FFT Filter. In this dialog youcan select the matrix to filter and both the low and high cutoff frequencies of the filter. The input matrix will be modified in orderto store the filtered data.

3.9.3.5.4 Band Block...

The Analysis -> FFT Filter -> Band Pass... command uses a 2D FFT based digital filter to remove a band of frequen-cies from a matrix while leaving those frequencies above and below the stop band, see the following article by Paul Bourkehttp://paulbourke.net/miscellaneous/imagefilter/ for more details. This command opens the FFT Filter Dialog with the filter typeset to Band Block FFT Filter. In this dialog you can select the matrix to filter and both the lower and upper stop-band frequenciesof the filter. The input matrix will be modified in order to store the filtered data.

3.10 The Table Menu

This menu is only active when a table is selected.

3.10.1 Set Column As

Selecting the Set Column As item opens a sub-menu of command that are used to define the kind of data stored in the variouscolumns of a table.

3.10.1.1 Set Column As -> X

Define the selected column as abscissa for the plots. You can define more than one column as X-values in a table, they arereferenced as X1, X2, etc.

3.10.1.2 Set Column As -> Y

For 2D plots, this command defines the selected column as Y-values for the plots. For 3D plots, Y columns can be used as thesecond abscissa.

3.10.1.3 Set Column As -> Z

For 3D plots, Z columns will be used as plotted values.

3.10.1.4 Set Column As -> X error

Define the selected column for use as the error bar width for the abscissae.

3.10.1.5 Set Column As -> Y error

Define the selected column for use as the error bar heights for the Y-values.

3.10.1.6 Set Column As -> Read-only

Set the selected columns as read-only.

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3.10.1.7 Set Column As -> Read/Write

Restore write access to the selected columns.

3.10.1.8 Set Column As -> label

Sets the selected columns as label columns. Can be used for comments and row descriptions.

3.10.1.9 Set Column As -> Disregard

No special function is assigned. The selected column can be used in different ways in several plots (as X values, Y values, etc).These columns are disregarded in statistical calculations.

3.10.2 Column Options...

This command is used to define the global parameters of each column such as numeric format, column name, etc. See thecorresponding dialog box section for more details.

3.10.3 Set Column Values...

This command is used to fill the selected column with the values resulting from a mathematical formula. See the correspondingdialog box section for more details.

3.10.4 Recalculate

When you fill a column (named for example ’C1’) with the results of a formula (by using the Set Column Values... command),the values of the column are calculated only once when you define the formula. If your formula depends on values of anothercolumn (name for example ’C2’), the values of ’C1’ are not updated if you modify the values in ’C2’. This command is used torecalculate the values of the selected column.

3.10.5 Fill column with

These commands are used to fill selected columns with special values:

3.10.5.1 Fill Column With -> Row Numbers

Each element in the column is filled with its corresponding row number.

3.10.5.2 Fill Column With -> Random Numbers

Each element in the column is filled with a random value between 0 and 1.

3.10.5.3 Fill Column With -> Normal Random Numbers

The rows in the selected column are filled with normally distributed random values calculate using the Ziggurat method with amean of 0.0 and a standard deviation of 1.0. The computational routine is from the Gnu Scientific Library (look here for moredetails).

3.10.6 Clear

Removes all the values of the selected column.

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3.10.7 Add Column

Adds a new column to the table. Regardless the selected column, new columns are inserted to the right of the rightmost columnin the table.

3.10.8 Set Columns...

Used to define the number of columns in the table. Columns are added/removed from the right hand side of the table. Be Careful!If you decrease the number of columns in a table, any data contained in the removed columns will be lost!

3.10.9 Hide Selected Columns

The Hide Selected Columns command hides all the selected columns. The remaining visible columns are grouped together intoa single block. Hidden columns may be shown using the Show All Columns command.

3.10.10 Show All Columns

The Show All Columns command unhides any hidden columns in the selected table.

3.10.11 Alignment

These commands are used to cusomize the alignment of the texts in the selected columns:

3.10.11.1 Alignment -> Left

The texts in the selected columns are aligned with the left edge of the columns.

3.10.11.2 Alignment -> Center

The texts in the selected columns are centered horizontally in the available space.

3.10.11.3 Alignment -> Right

The texts in the selected columns are aligned with the right edge of the columns.

3.10.12 Adjust Column Width

The Adjust Column Width command resets the width of all selected columns to a value that is optimal for the data that iscontained in the column. Optimal width is considered to be just wide enough to show all digits.

3.10.13 Move to First

Moves the selected column to the beginning of the table.

3.10.14 Move Left

Moves the selected column to the left.

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3.10.15 Move Right

Moves the selected column to the right.

3.10.16 Move to Last

Moves the selected column to the end of the table.

3.10.17 Swap columns

Swaps the selected columns.

3.10.18 Set Rows...

Allows direct definition of the number of rows in the table. Rows are added/removed from the end of the table. Be Careful! Ifyou decrease the number of rows in a table, any data contained in removed rows will be lost.

3.10.19 Delete Rows Interval...

A dialog is opened that permits selection, and subsequent deletion, of a range of rows selected by row index number.

3.10.20 Move Row

These commands are used to move selected rows up or down in a table:

3.10.20.1 Move Row -> UP

The selected row is moved up one place in the table.

3.10.20.2 Move Row -> DOWN

The selected row is moved down one place in the table.

3.10.21 Go to Row... (Ctrl-Alt-G)

This command opens a dialog which allows you to select the row index that will become the current row in the selected table ormatrix.

3.10.22 Go to Column... (Ctrl-Alt-C)

This command opens a dialog which allows you to select the column index that will become the current column in the selectedtable or matrix.

3.10.23 Extract Data...

The Extract Data... command opens a dialog which allows you to define a set of conditions that are used to filter the data in thecurrently active table. When a condition has been defined, Applying the condition will create a new table into which all rows thatmeet the condition will be copied. The original table is unchanged. For example, the condition col("1") > 0.5 will generate anew table that contains all the rows from the active table which have a value greater than 0.5 in column 1. See the correspondingdialog box section for more details.

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3.10.24 Convert to Matrix

The commands in this submenu may be used to convert a table into a matrix. Their main utility might be to import data fromfiles into matrices: first import the data into a table and then use these commands to convert the table into a matrix.

3.10.24.1 Convert to Matrix -> Direct

This command creates a new matrix having the same dimensions (rows/columns) as the input table. Each cell in the table has itscorresponding cell in the resulting matrix. There are no special requirements on the data values in the table to be converted.

3.10.24.2 Convert to Matrix -> 2D Binning...

This command bins XY data, meaning that it creates a frequency count of the data points falling within a given XY range andstores the bin counts as Z values in a new matrix. It opens the the Bin Matrix Dialog that allows to customize the new matrix interms of dimensions and coordinates. The input data must be a single Y column that has a X column associated to it.

3.10.24.3 Convert to Matrix -> Regular XYZ

This command creates a new matrix from a a table that contains regularly spaced XY data. In order for the input data to beclassified as regular, the values in the X and Y columns must meet specific requirements: each X value must have the samenumber of Y values and each Y value must have the same number of X values. In addition, both the X and the Y data valuesmust be equally spaced: only small irregularities of the data are allowed (15% tolerance).

3.10.24.4 Convert to Matrix -> Random XYZ...

Opens the the Random XYZ Gridding dialog that allows to customize the process of generating a new matrix from a collectionof randomly distributed XYZ data samples, using Shepard’s method. The input data must be a single Z column that has a X anda Y column associated to it.

3.11 The Matrix Menu

This menu is only active when a matrix is selected.

3.11.1 Set Properties...

This command opens a dialog window which is used to specify some view parameters of the matrix (cell width, format ofnumbers).

3.11.2 Set Dimensions... (Ctrl-D)

This command opens a dialog window which is used to specify the size of a matrix. It can also be used to specify the X and Yranges which will be used as axis ranges for a 3D-plot of the matrix data.

3.11.3 Set Values... (Ctrl-Q)

This command opens a dialog window which is used to fill in a matrix with the result of a function z=f(i,j) in which i and j standfor the row and column numbers.

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3.11.4 Recalculate (Ctrl-Return)

This command allows you to recalculate the matrix cell values using a predefined formula. Useful when the formula is changed.

3.11.5 Rotate 90 (Ctrl-Shift-R)

This command performs a clockwise 90 degrees rotation of the active matrix.

3.11.6 Rotate -90 (Ctrl-Alt-R)

This command performs a counterclockwise 90 degrees rotation of the active matrix.

3.11.7 Flip V (Ctrl-Shift-V)

Flips the selected matrix vertically.

3.11.8 Flip H (Ctrl-Shift-H)

Flips the selected matrix horizontally.

3.11.9 Expand...

Opens the matrix resampling dialog. Expanding operation is preselected in the dialog.

3.11.10 Shrink...

Opens the matrix resampling dialog. Shrinking operation is preselected in the dialog.

3.11.11 Smooth

Matrix smoothing is performed by shrinking and then expanding the matrix using bilinear interpolation. If the number of columnsor rows is less than 32, the matrix is first expanded so that the row number and the column number are both twice of the original.Then the expanded matrix is shrunk to the original size. Through this process of expanding and shrinking, the size of the outputmatrix will be exactly the same as the original matrix. However, the data will be much smoother. If both the number of columnsand the number of rows in the original matrix are greater than 31, the matrix is first shrunk and then expanded to obtain thesmoothed matrix.

3.11.12 Transpose

Perform a Transpose operation on the selected matrix.

3.11.13 Invert

Invert the selected matrix.

3.11.14 Determinant

Compute the determinant of the selected matrix.

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3.11.15 Go To Commands

The Go to Row... and Go to Column... commands are the same as those described in the Table menu

3.11.16 View Commands

This group of commands allows you to choose how the matrix will be displayed.

3.11.16.1 Image mode (Ctrl-Shift-I)

Displays the selected matrix as an image.

3.11.16.2 Data mode (Ctrl-Shift-D)

Displays the selected matrix as a data table.

3.11.17 Palette

3.11.17.1 Gray Scale Map

If the selected matrix is viewed as an image, this command sets the palette to a gray scale.

3.11.17.2 Rainbow

If the selected matrix is viewed as an image, this command sets the palette to a predefined color scale.

3.11.17.3 Custom

Opens the Custom Color Map dialog allowing customization of the palette used by the selected matrix when the matrix isdisplayed as an image.

3.11.18 Show Column/Row (Ctrl-Shift-C)

When this option is checked, the horizontal and vertical headers of the selected matrix will display the column/row indexes.

3.11.19 Show X/Y (Ctrl-Shift-X)

When this option is checked, the horizontal and vertical headers of the selected matrix will display the x/y coordinates.

3.11.20 Convert to Spreadsheet

Convert the selected matrix into a table.

3.12 The Format Menu

This menu is only active when a plot is selected.

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3.12.1 Apply Template...

Opens an existing QtiPlot template file (.qpt) and applies it to the active plot window.

3.12.2 Edit Range...

Opens the Edit Curve Range dialog for 2D plots. It is used to customize the visible data range of the curves in the active 2D plotlayer. This dialog can be opened only if there is a selected data curve in the active plot layer.

3.12.3 Plot Associations...

Opens the Plot Associations dialog for 2D plots. It is used to select the columns of a table to be used as X, Y and error values forthe plot curves in the active 2D plot layer. This dialog is only available if the active plot layer contains data curves.

3.12.4 Plot...

For classical 2D plots, opens the format plot dialog with the general plot options tab selected. It is used to customize line stylesand colors of the plot frame, etc.

For surface plots, this command opens the surface plot options with the general plot options tab selected. In this case the aspectratio of the plot can also be modified.

3.12.5 Curves...

Opens the Custom Curves dialog. Used to customize the line style and colors used to draw curves.

If the selected plot is a surface plot, this menu item is not shown.

3.12.6 Scales...

Opens the format plot dialog with the scales tab selected. Used to customize the ranges on the different axes. Note that anymodification in an associated table, or of the plotted curves, will result in a reset of these scales to the default values.

For surface plots, this command opens the surface plot options with the scales options tab selected.

3.12.7 Axes...

Opens the format plot dialog with the axes tab selected. Used to customize the settings for the different axes, such as axis/ticksize and color, axis labels, etc.

For surface plots, this command opens the surface plot options with the axis options tab selected.

3.12.8 Grid...

Opens the format plot dialog with the grid tab selected. Used to add and customize grid lines on the different axes.

This menu item is not shown for surface plots.

3.12.9 Title...

Opens a text options dialog, which permits modification of text and properties (color, font, alignment) of the plot title.

For surface plots, this command opens the surface plot options with the title options tab selected.

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3.13 The Windows Menu

In addition to the items listed below, this menu will also display a list containing the first ten windows created in the workspace.These windows can be made active, or can be shown if they are hidden, by selecting their name from the list. If your projectcontains more then ten windows, you must use the Project explorer in order to perform these operations on the remainingwindows.

3.13.1 Folders

Opens a menu displaying a list of all the folders and subfolders in the project. The active folder is highlighted. You can changethe active folder in a project by selecting an item from this list.

3.13.2 Cascade

Arranges the visible windows in the project in a cascading style.

3.13.3 Tile

Tiles the visible windows in the project.

3.13.4 Next (F5)

Makes the next visible window in the workspace stack the active window.

3.13.5 Previous (F6)

Makes the previous visible window in the workspace stack the active window.

3.13.6 Find...

Opens the Project Explorer Find dialog which permits searching a window anywhere in the project.

3.13.7 Rename Window

Opens the Window Properties dialog permitting you to change the title (name and/or label) or to set comments for the currentlyactive window.

3.13.8 Duplicate

Clones the active window.

3.13.9 Script Window (F3)

Opens the script console window.

3.13.10 Window Geometry...

Opens a dialog used to change the size and the position of the active window. The size of any contained plots will be scaled tothe new window size.

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3.13.11 Hide Window

Hides the active window. A hidden window can be made visible again using the Project explorer.

3.13.12 Close Window (Ctrl-W)

Closes the active window. A dialog will pop-up asking you to confirm the operation if the corresponding option in the Preferencesdialog ("Confirmations" tab) is checked.

3.13.13 Numbered Window List

A numbered list of the current folder’s windows appears at the bottom of the Window Menu. This list may contain up to 9 entries.Clicking on one of the entries in this list will activate that window (that is, display the window, and unhide it if necessary. If thereare more than 9 entries, the More Windows... command will be added to the Window Menu immediately following the last itemin the numbered window list. Selecting the More Windows... command opens the Project Explorer, which provides access to allwindows in all folders in the project.

3.14 Customization of 3D plots

These commands are not available in any menu or by using any keyboard shortcut. However, they can be accessed through the3D toolbar.

3.14.1 Frame

This command can be accessed by a click on the

Draws only the three axes on the active 3D plot.

3.14.2 Box

This command can be accessed by a click on the

Draws the three axes on the active 3D plot, and a box around it.

3.14.3 No axes

This command can be accessed by a click on the

Doesn’t draw the three axes nor the box on the active 3D plot.

3.14.4 Front Grid

This command can be accessed by a click on the

Draws a grid on the front panel of the active 3D plot. The position of this grid is on the plane defined by y=ymin.

3.14.5 Back Grid

This command can be accessed by a click on the

Draws a grid on the back panel of the active 3D plot. The position of this grid is on the plane defined by y=ymax.

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3.14.6 Left Grid

This command can be accessed by a click on the

Draws a grid on the left panel of the active 3D plot. The position of this grid is on the plane defined by x=xmin.

3.14.7 Right Grid

This command can be accessed by a click on the

Draws a grid on the right panel of the active 3D plot. The position of this grid is on the plane defined by x=xmax.

3.14.8 Ceiling Grid

This command can be accessed by a click on the

Draws a grid on the top panel of the active 3D plot. The position of this grid is on the plane defined by z=zmax.

3.14.9 Floor Grid

This command can be accessed by a click on the

Draws a grid on the floor panel of the active 3D plot. The position of this grid is on the plane defined by z=zmin.

3.14.10 Enable perspective

This command can be accessed by a click on the

Enables/Disables 3D perspective mode.

3.14.11 Reset rotation

This command can be accessed by a click on the

Resets the rotation of the 3D plot to the default value.

3.14.12 Fit frame to window

This command can be accessed by a click on the

Finds the best layout of the 3D plot to fit the window size. It readjusts the length of the axis ticks to a default value.

3.14.13 Bars Style

This command can be accessed by a click on the

If the active 3D plot is a 3D histogram, this command permits modification of the style used to draw the bars.

3.14.14 Dots

This command can be accessed by a click on the

If the active 3D plot is a 3D scatter, this command permits modification of the style used to draw data points as dots.

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3.14.15 Cones

This command can be accessed by a click on the

If the active 3D plot is a 3D scatter, this command permits modification of the style used to draw data points as cones. It it thenpossible to modify the drawing parameters of the cones by double clicking on the plotting area.

3.14.16 Cross Hairs

This command can be accessed by a click on the

If the active 3D plot is a 3D scatter, this command permits modification of the style used to draw data points as cross-hairs. It itthen possible to modify the drawing parameters of the crosses by double clicking on the plotting area.

3.14.17 3D Wire Frame

This command can be accessed by a click on the

If the active 3D plot is a 3D surface, this command is used to modify the style of the surface to be drawn as a simple wireframe.

3.14.18 3D Hidden Lines

This command can be accessed by a click on the

If the active 3D plot is a 3D surface, this command is used to modify the style of the surface to be drawn as a wireframe. Acomputation of hidden lines is performed.

3.14.19 3D Polygons

This command can be accessed by a click on the

If the active 3D plot is a 3D surface, this command is used to modify the style of the surface to be drawn as polygons.

3.14.20 3D Wire Surface

This command can be accessed by a click on the

If the active 3D plot is a 3D surface, this command is used to modify the style of the surface to be drawn as polygons with amesh.

3.14.21 Floor Data Projection

This command can be accessed by a click on the

If the active 3D plot is a 3D surface, this command is used to add a filled area projection of the surface on the floor of the plot.

3.14.22 Floor Isolines

This command can be accessed by a click on the

If the active 3D plot is a 3D surface, this command is used to add an isoline.

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3.14.23 Empty Floor

This command can be accessed by a click on the

If the active 3D plot is a 3D surface, this command is used to remove any projection from the floor.

3.14.24 Animation

This command can be accessed by a click on the

Enables/disables animation.

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Chapter 4

The Toolbars

Groups of related commands are collected together in a number of toolbars. All toolbars can be moved and docked in a moreconvenient location (left, right or bottom sides of the application window) or moved onto the desktop (outside the main window)using drag-and-drop, using their left side handle. Toolbars are automatically enabled/disabled depending on the currently activewindow. For example, if the current window is a table, the Table toolbar will be enabled and all the other toolbars will beautomatically disabled.

The same approach is used for showing/hiding toolbars: if there are no visible tables in the workspace, the Table toolbar willbe automatically hidden. It will be shown again when the user adds a new table into the project. Toolbars can also be manuallyshown/hidden at any time by right-clicking on the Toolbars... command from the View menu or entering Ctrl-Shift-T and thenchecking/unchecking the corresponding item in the pop-up menu.

Visible toolbars will be shown in one of two possible formats depending upon the space available at the docking location. Bydefault, when there is sufficient room, all tool icons will be shown in a single row or column. If there is not sufficient room toshow all icons in one row, the toolbar will be collapsed to the extent necessary to fit the toolbar into the available space. In thiscase, the ">>" symbol will be shown to indicate that there are hidden command icons. As long as the toolbar is not disabled, leftclicking on the ">>" symbol will temporarily expand the toolbar and show the hidden commands, which may then be left clickedto execute them. Moving the mouse pointer off of the toolbar will automatically collapse it. Note that toolbars located on thedesktop are always shown expanded.

4.1 The Edit Toolbar

Figure 4.1: The QtiPlot Edit Toolbar

4.2 The File Toolbar

The File Toolbar provides single-click access to commands from the File menu. Refer to this section for a more completedescription of these commands.

Figure 4.2: The QtiPlot File Toolbar

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Icon Command Key Description

Undo command Ctrl-Z Undo the last command, this feature doesn’t work for plot mod-ifications. See the Undo command command for more details.

Redo command Ctrl-Shift-Z Redo the last command, this feature doesn’t work for plot mod-ifications. See the Redo command command for more details.

Cut Selection Ctrl-X Cut the current selection.Copy Selection command Ctrl-C Copy the current selection.Paste Selection command Ctrl-V Paste the current selection.Delete Selection command Del Delete the current selection.

Table 4.1: Edit toolbar commands.

Icon Command Key DescriptionNew Window/FolderCommands

Selects the last used window/folder creation command or se-lects a new one from a drop down list.

New Function/SurfaceCommands

Selects the last used function/surface creation command or se-lects a new one from a drop down list.

Open Commands Selects the last used open command or selects a new one froma drop down list.

Append Project... command Ctrl-Alt-A Appends an existing QtiPlot project file as a new folder to thecurrent project.

Save Project command Ctrl-S Saves the current project.Save as Template command Saves the current graph window as a template.Import -> Import ASCII...command Ctrl-K Imports ASCII files.

Duplicate command Clones the active window.Print command Ctrl-P Prints the active window.Print Preview command Previews the active window for printing.Export to PDF command Ctrl-Alt-P Exports the active window formatted as a PDF file.

Project Explorer Ctrl-E Shows or hides the project explorer.Results log Shows or hides the results window.Script Window command F3 Shows the script window.

Table 4.2: File toolbar commands.

Icon Command Key DescriptionNew Project command Ctrl-N Create a new project.New Folder command F7 Add a new folder.New Table command Ctrl-T Create a new table.New Matrix command Ctrl-M Create a new matrix.New Note command Create a new note window.New Graph command Ctrl-G Creates a new, empty graph window (2D plot).

Table 4.3: New Window/Folder Commands

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Icon Command Key DescriptionNew Function Plot... command Ctrl-F Creates a new plot based on a function Y=f(X).New Parametric FunctionPlot... command

Creates a new parametric plot: the (X,Y) data points are com-puted using functions of a variable (m), X=f1(m) and Y=f2(m).

New 3D Surface Plot...command Ctrl-Alt-Z Creates a new 3D plot based on a function Z=f(X,Y).

New 3D Parametric SurfacePlot... command

Creates a new 3D parametric plot: the (X,Y,Z) data points arecomputed using functions of the latitude and longitude vari-ables u and v.

Table 4.4: New Function/Surface Commands

Icon Command Key DescriptionOpen command Ctrl-O Opens an existing QtiPlot project file.Open Template command Opens an existing QtiPlot template file.

Open Excel command Ctrl-Shift-E Imports an Excel workbook into new tables (and plots if Excelis installed).

Open ODF Spreadsheetcommand Ctrl-Alt-S Imports an ODF spreadsheet into new tables.

Table 4.5: Open Commands

4.3 The Plot Toolbar

This toolbar is only active when a graph window is selected. It provides single-click access to the commands of the Graph menuand of the Data menu which are used for the modification of plots and the data points of the plots.

Figure 4.3: The QtiPlot Plot Toolbar

4.4 The Layers Toolbar

This toolbar is only active when a graph window is selected. It provides single-click access to the commands of the Graph menuwhich can be used in order to create and manipulate multi-layer 2D graphs.

Figure 4.4: The QtiPlot Layers Toolbar

4.5 The Table Toolbar

This toolbar provides single-click access to the Plot Menu commands. These are used to plot data from tables.

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Icon Command Key DescriptionAdd Error Bars... Ctrl-B Adds error bars to a curve on the active plot layer.

Add/Remove Curves... Alt-C Adds curves to, or removes curves from, the active plot win-dow.

Add Function... Ctrl-Alt-F Adds a curve based on a function to the active plot layer.New Legend Ctrl-L Adds a new legend to the active plot layer.Add Color Scale Adds a new color scale legend to the active plot layer.Exchange X-Y Axes Swaps the X and Y axes of the the active layer.Rescale To Show All Ctrl-Shift-R Rescales the axes to show all data points.

Disable toolsReverts to normal pointer mode. Useful when you have se-lected another pointer mode on a plot layer, such as the datareader.

Zoom Commands Selects the last used zoom tool or selects a new one from a dropdown list.

Select Data Range Alt-S Switches the active plot layer into Select Data Range mode.

Read Data Commands Selects the last used data reader tool or selects a new one froma drop down list.

Edit Data Commands Selects the last used data edit tool or selects a new one from adrop down list.

Add Text Commands Selects the last used add text tool or selects a new one from adrop down list.

Add Line/Arrow Commands Selects the last used add arrow/line tool or selects a new onefrom a drop down list.

Geometric Shape Commands Selects the last used geometric shape tool or selects a new onefrom a drop down list.

Add Image Alt-I Inserts a new image into the active plot layer.

Z-order CommandsSelects the last used Z-order tool or selects a new one from adrop down list. These tool buttons are available only when oneor more annotation objects are selected in the active plot layer.

Align Objects CommandsSelects the last used alignment tool or selects a new one froma drop down list. These tool buttons are available only whenseveral annotation objects are selected in the active plot layer.

Table 4.6: Plot toolbar commands

Icon Command Key DescriptionZoom In/Out and Drag Canvas Switches the active plot layer into dynamic zoom/drag mode.Zoom/Drag CanvasHorizontally

Switches the active plot layer into dynamic horizontal zoom/-drag mode.

Zoom/Drag Canvas Vertically Switches the active plot layer into dynamic vertical zoom/dragmode.

Zoom in Ctrl-+ Switches the active plot layer into zoom mode.Zoom out Ctrl-- Zooms the active plot layer out one step in the zoom history.

Table 4.7: Plot Toolbar Zoom Commands

Icon Command Key DescriptionData Reader Ctrl-D Switches the data display into Data Reader mode.Annotation Switches the active plot layer into Annotation mode.Screen Reader Switches the active plot layer into Screen Reader mode.

Table 4.8: Read Data Commands

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Icon Command Key DescriptionDraw Data Points Adds new data points on the active plot layer.

Move Data points Ctrl-Alt-M Allows drag-mode moving of data points on the active plotlayer.

Remove Bad Data Points Alt-B Allows removal of data points from the active plot layer.Remove Bad Data Points Drags a selected curve around on plot layer.

Table 4.9: Edit Data Commands

Icon Command Key DescriptionAdd Text Alt-T Adds a new text element on the active plot layer.Add Equation... command Alt-Q Adds a new Tex formatted equation on the active plot layer.Add Time Stamp Ctrl-Alt-T Adds a time/date label on the active plot layer.

Table 4.10: Add Text Commands

Icon Command Key DescriptionDraw Arrow Ctrl-Alt-A Adds a new arrow on the active plot layer.Draw Line Ctrl-Alt-L Adds a new line on the active plot layer.

Table 4.11: Add Line/Arrow Commands

Icon Command Key DescriptionAdd Rectangle Ctrl-Alt-R Adds a new rectangle on the active plot layer.Add Ellipse Ctrl-Alt-E Adds a new ellipse (circle) on the active plot layer.

Table 4.12: Geometric Shape Commands

Icon Command Key DescriptionMove to Top Moves the selected item to the top of the layer’s z-order.Move to Bottom Moves the selected item to the bottom of the layer’s z-order.

Table 4.13: Z-order Commands

Icon Command Key DescriptionAlign Left Aligns selected plot objects along the left edge.Align Right Aligns selected plot objects along the right edge.Align Top Aligns selected plot objects along the top edge.Align Bottom Aligns selected plot objects along the bottom edge.

Table 4.14: Align Objects Commands

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Icon Command Key Description

Add Layer Commands Selects the last used add layer tool or selects a new one from adrop down list.

Arrange Layers... Shift-A Opens a dialog for rearranging all layers of the active graphwindow.

Automatic Layout Automatically rearranges all layers of the active graph window.

Extract to Layers Extracts datasets (curves) from the active layer onto separatelayers.

Extract to Graphs... Extracts all layers in the active graph window to separategraphs.

Merge Graph Windows...Opens the Graph Manipulation dialog that allows users tochoose the graph windows to be merged in a new 2D plot win-dow.

Table 4.15: Layers toolbar commands

Icon Command Key DescriptionAdd Layer Alt-L Adds a new layer to the active plot window.Add Empty Inset Layer Adds an empty inset layer to the active graph window.

Add Inset Layer With Curves Adds an inset layer to the active graph window that containscopies of any curves in the active plot layer.

Add Horizontal Axis Adds a central horizontal axis to the active plot layer.Add Vertical Axis Adds a central vertical axis to the active plot layer.

Table 4.16: Add Layer/Axes Commands

Figure 4.5: The QtiPlot Table Toolbar

4.6 The Column Toolbar

This toolbar provides single-click access to the commands of the Table Menu which are used to rearrange columns in the table,fill columns with values and define the plot role of selected columns. A few items from the Analysis menu are also included onthis toolbar.

Figure 4.6: The QtiPlot Column Toolbar

4.7 The Plot 3D Toolbar

Figure 4.7: The QtiPlot Plot 3D Toolbar

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Icon Command Key DescriptionLine Plots Line, Horizontal Steps, Vertical Steps

Scatter Plots Scatter, Vertical Drop Lines

Line & Symbol Plots Line+Symbol, Spline

Bar Chart Plots Columns, Rows, Stack Column, Stack Bar

plot -> Area Plots selected data using area style.plot -> 2D BW Pie Chart Plots selected data using pie style.

Statistical Plots Box, Histogram, Stacked Histogram, Stem-Leaf

Vector Plots Vectors XYXY. Vectors XYAM

Special Line/Symbol Plots Double-Y, Waterfall, Zoom, Vert. 2 Layer, Horiz. 2-Layer, 4Layer, Stacked Layer, Custom

3D Plots Bars, Ribbons, Scatter, Trajectory

Table 4.17: Table toolbar commands.

Icon Command Key Descriptionplot -> Line Plots selected data using line style.plot -> Horizontal Steps Plots selected data using horizontal steps style.plot -> Vertical Steps Plots selected data using vertical steps style.

Table 4.18: Line Plots

Icon Command Key Descriptionplot -> Scatter Plots selected data using scatter style.

plot -> Scatter Central Plots a graph of the selected data columns using "Scatter" styleand the X and Y axes located in the middle of the layer.

plot -> Vertical Drop Lines Plots selected data using vertical drop lines style.plot -> Bubble Plots selected data using indexed sizes for the plot symbols.

plot -> Color Mapped Plots selected data using a default color map for the plot sym-bols.

plot -> Bubble + ColorMapped

Plots selected data using indexed sizes and a default color mapfor the plot symbols.

Table 4.19: Scatter Plots

Icon Command Key Descriptionplot -> Line+Symbol Plots selected data using line+symbol style.plot -> Spline Plots the selected data columns using spline style.

Table 4.20: Line & Symbol Plots

Icon Command Key Descriptionplot -> Columns Plots selected data using columns style.plot -> Rows Plots selected data using rows style.plot -> Special Bar/Column ->Stack Column Plots selected data using stack column style.

plot -> Special Bar/Column ->Stack Bar Plots selected data using stack row style.

Table 4.21: Bar Chart Plots

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Icon Command Key Descriptionplot -> Box Plot Plots selected data using Box style.plot -> Histogram Plots selected data using histogram style.plot -> Stacked Histogram Plots selected data using stacked histogram style.plot -> Stem and Leaf Plots selected data using Stem and Leaf style.

Table 4.22: Statistical Plots

Icon Command Key Descriptionplot -> Vectors XYXY Plots selected data using xyxy vector style.plot -> Vectors XYAM Plots selected data using xyam vector style.

Table 4.23: Vector Plots

Icon Command Key DescriptionPlot -> Multi-Curve ->Double-Y Plots selected data using two different Y axes.

Plot -> Multi-Curve -> 3Y:Y-YY Plots selected data using three different Y axes.

Plot -> Multi-Curve -> 4Y:YY-YY Plots selected data using four different Y axes.

Plot -> Multi-Curve -> ZoomPlots selected data in one plot layer along with a magnified re-gion of that data in another plot layer on the same graph win-dow.

Plot -> Multi-Curve -> StackLines by Y Offsets

Creates a new graph window containing a Stacked Lines plotgenerated from data in the selected columns. Each column isdrawn as a separate curve which has a vertical offset from theprevious one.

Plot -> Multi-Curve ->Waterfall Creates a Waterfall plot from a series of selected columns.

Plot -> Multi-Curve ->Colormapped Lines

Creates a new graph window displaying each selected data setas a line curve and a color scale legend that maps the colors ofthe curves to the column indices.

plot -> Vertical 2 Layers Plot 2 vertically arranged layers on the same graph window.plot -> Horizontal 2 Layers Plot 2 horizontally arranged layers on the same graph window.plot -> 4 Layers Plot 4 layers on the same graph window.

plot -> Stacked Layers Plot a stacked layer for each selected column, all on the samegraph window.

plot -> Custom Layout... Opens the Arrange Layers dialog to set up custom layouts.

Table 4.24: Special Line/Symbol Plots

Icon Command Key Descriptionplot -> Bars Plots selected data using 3D bars style.plot -> Ribbons Plots selected data using 3D ribbons style.plot -> Scatter Plots selected data using 3D scatter style.plot -> Trajectory Plots selected data using trajectory style.

Table 4.25: 3D Plots

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Icon Command Key DescriptionTable -> Add Column Alt-C Adds a new column to the selected table.Table -> Set Column Values... Alt-Q Used for functional assignment of values in selected column.Table -> Fill Column With ->Row Numbers

Fills each row in the selected column with it’s correspondingrow number.

Table -> Fill Column With ->Random Numbers Fills each row in the selected column with a random value.

Table -> Fill Column With ->Normal Random Numbers

Fills each row in the selected column with a normally dis-tributed random value.

Analysis -> Sort Column ->Ascending Sorts selected columns separately in ascending order.

Analysis -> Sort Column ->Descending Sorts selected columns separately in descending order.

Analysis -> Sort Table Sorts all columns in the selected table into ascending or de-scending order.

Analysis -> Statistics onColumns Computes statistical parameters on selected columns.

Analysis -> Statistics on Rows Computes statistical parameters on the selected rows.Table -> Set Column As -> X Define the selected column as abscissae for plotting.Table -> Set Column As -> Y Define the selected column as an ordinate for plotting.Table -> Set Column As -> Z For 3D plots, Z columns will be used as height values.Table -> Set Column As -> Yerror Define the selected column for use as error bars for Y-values.

Table -> Set Column As ->label Define the selected column as containing labels.

Table -> Set Column As ->Disregard This command removes any plot role from selected columns.

Table -> Move to First Moves the selected column to the beginning of the table.Table -> Move Left Moves the selected column to the left.Table -> Move Right Moves the selected column to the right.Table -> Move to Last Moves the selected column to the end of the table.Table -> Swap columns Swap the selected columns.Table -> Move Row -> UP Moves selected row UP one slot in table.Table -> Move Row -> DOWN Moves selected row DOWN one slot in table.

Table -> Increase Precision Increases the number of digits displayed in the selectedcolumns.

Table -> Decrease Precision Decreases the number of digits displayed in the selectedcolumns.

Table -> Adjust Column Width Sets an optimal width on the selected columns.Table -> Alignment ->Alignment -> Left

The texts in the selected columns are aligned with the left edgeof the columns.

Table -> Alignment ->Alignment -> Center

The texts in the selected columns are centered horizontally inthe available space.

Table -> Alignment ->Alignment -> Right

The texts in the selected columns are aligned with the right edgeof the columns.

Table 4.26: Column toolbar commands.

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Icon Command Key Descriptionplot -> Frame Draw only the three axes.plot -> Box Draw the three axes and the 3D box around the plot.plot -> No axes Doesn’t draw the axes nor the box.plot -> Front Grid Draw a grid on the front panel.plot -> Back Grid Draw a grid on the back panel.plot -> Left Grid Draw a grid on the left panel.plot -> Right Grid Draw a grid on the right panel.plot -> Ceiling Grid Draw a grid on the top panel.plot -> Floor Grid Draw a grid on the bottom panel.plot -> Enable perspective Enables/Disables the 3D perspective mode.plot -> Reset rotation Resets the rotation of the 3D plot to the default values.

plot -> Fit frame to window Finds the best layout of the 3D plot fitting the window size. Itreadjusts the length of the axis ticks to a default value.

plot -> Bars Style Changes the styles of the bars.plot -> Dots Draw the 3D scatter points with the dot style.plot -> Cones Draw the 3D scatter points with the cone style.plot -> Cross Hairs Draw the 3D scatter points with the cross-hairs style.plot -> 3D Wire Frame Draw a surface with the wireframe style.plot -> 3D Hidden Lines Draw a surface with the mesh style (with hidden lines).plot -> 3D Polygons Draw a surface with the polygons style.plot -> 3D Wire Surface Draw a surface with the mesh+polygons style.plot -> Floor Data Projection Draw a projection of the plot on the floor.plot -> Floor Isolines Draw an isolines projection on the floor.plot -> Empty Floor Draw an empty floor.

plot -> Animation Enables/Disables animation.

Table 4.27: 3D Plot toolbar commands.

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Chapter 5

The Dialogs

5.1 Window Properties Dialog

This dialog can be opened using the Rename Window command from the Windows menu or by right-clicking on the title bar ofa project window and selecting the Properties... action from its context menu.

Figure 5.1: The Rename Window dialog box.

With this dialog it is possible to change the default Name and Label of a project window as well as its Window Title displaypolicy: Name, Label or Both Name and Label. It also makes possible to set some Comments for the project window.

The dialog also displays basic information about the project window: the creation date and time, its Status and its internal Pathwithin the project.

5.2 Add Custom Action

This dialog helps you define new Python script launchers that will be added to menus or tool bars in QtiPlot. You can fullycustomize script launchers by defining: 1) a textual description that will be displayed in the destination menu, (2) an icon, (3) ashortcut key sequence and (4) a tool tip. The Tool Tip Text is a short description that is displayed near the launcher button whenyou hover the mouse over it. You must assign unique shortcut key sequences to your custom launchers.

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Figure 5.2: The Add Custom Script Action... dialog box.

The Script File is the path to the Python script that will be executed when you click the launcher. When you click the Add button,all the settings for the new launcher are saved to an XML file in the directory specified in the Folder box. On start-up QtiPlotparses all XML files in this folder and creates the corresponding menu items or toolbar buttons. When you press the Removebutton, the launcher selected in the left side list of the dialog is removed from QtiPlot menus/tool bars and the correspondingXML file is deleted from the hard disk. Make sure that you have backed up the file if you will ever need it in the future!

5.3 Custom Color Map

This dialog helps you define a custom color map and quickly edit its settings. It can be activated by selecting the Customcommand from the Matrix -> Palette menu if you are working with a matrix window or by pressing the button from theSymbol tab of the plot details dialog if you are editing a 2D plot curve.

The dialog displays a table with a set of levels and the color corresponding to each level. You can then add, remove or modifylevels from the definition of the colormap. It is also possible to save/load a custom color map to/from a XML file.

As long as the Scale Colors checkbox remains checked, values that fall between the colormap levels will be displayed in colorsthat are interpolated between the colors defined for the bounding levels. It is also possible to define discrete colors for each level.To do this you must uncheck the Scale Colors checkbox. In this case no interpolation will be done and you must define enoughlevels in your colormap to produce a desirable result.

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Figure 5.3: The Custom Color Map dialog box.

A click on the Level column header opens a dialog alowing to quickly edit the color map levels by specifying their total numberand an intensity range from Minimum to Maximum.

Figure 5.4: Set Equidistant Levels dialog box.

A click on the Color column header opens a dialog alowing to quickly customize the colors in the map by specifying the Fromand To colors and a color policy (Two Colors or Custom Color Map).

Figure 5.5: The Two Colors mode of the Gradient Fill dialog box.

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Figure 5.6: The Custom Color Map mode of the Gradient Fill dialog box.

5.4 Add Error bars

This dialog is activated by selecting the Add Error Bars... command from the Graph menu.

This command is used to plot X and/or Y error bars at each data point.

Note that clicking on the "Close" button will not add any error bars to the plot. You must set up the parameters for the error barsfirst and then click on the "Add" button. If you click on "Close" without clicking "Add", there will be no error bars drawn.

Figure 5.7: The Error bars dialog.

There are five ways to specify the sizes of the bars:

1) From a column of the table: In this case, the values in the selected column are used to compute the error bars. Specifically,if V is the value of a data point, and E the value from the same row of the errorbar column, the size of the correspondingbar will be V-E to V+E.

2) A percentage of the values: This command adds a new column to the table associated with the plot and fills it with result ofcalculating V*E/100 for each row in the table, where V is the plotted value and E is the selected percentage. This columnis then used to plot the error bars in exactly the same manner as in the previous case. The new column can subsequentlybe edited like any other column. Any changes will be reflected in the size of the corresponding error bars.

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3) The standard deviation of the values: This command first calculates the standard deviation of the plotted values. This hasmeaning only if the data are centered around an average value. As with the previous option, a new column will be createdin the active table and each row will be filled with the computed standard deviation. The program does not know andcannot compute individual standard deviations at each point. If this is required, you will need to independently computethese values from multiple samples taken at each x or y value.

4) The standard error of the values: This command first calculates the standard error of the plotted data values. A new columnwill be created in the active table and each row will be filled with the computed standard error.

5) The square root of the values: This command first calculates the square root of the plotted data values. A new column willbe created in the active table and each row will be filled with the computed square root.

The default style of the error bars (color, line width, cap length, etc...) can be customized via the Error Bars tab of the Preferencesdialog.

If you need to display asymmetric error bars you must define two sets of error bars for the same curve: one for the upper limits(with disabled minus side) and one for the lower limits (with disabled plus side).

Figure 5.8: Example of a plot with both X and Y Error Bars.

5.5 Function Dialog

This dialog box is used to add a function curve to the active plot or to edit an already existing function curve. In the latter case itis embedded into the Plot details dialog

The plotted function is built with the common operators *, +, /, -, and ˆ (for multiplication, addition, division, subtraction andexponentiation, respectively). A complete set of intrinsic functions are available and these are listed in the muParser section ofthe chapter on Mathematical Expressions and Scripting.

The first item is the Curve Type and is used to select the form of the generator function. The simplest and most common functiondefinition is the classical Cartesian coordinate definition, y=f(x). This is the default option and is simply named "Function". Justbelow this is a text pane in which to enter the function definition.

On the left side of the text pane there are two buttons. By pressing the first one, displaying the capital greek letter sigma, a drop-down menu of intrinsic functions grouped by the first letter of their name will be shown. Brief descriptions of the functions aredisplayed by hovering the cursor over the function name. Selecting a function name will copy it into the function definition pane.

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By pressing the second button, which displays a pencil icon, a dialog containing a dropdown list of recently typed expressionswill pop-up. Selecting an expression will copy it into the function definition pane.

The next two parameters are used to select the X-range to be used for the plot. The third parameter sets the number of data pointsto be computed in the selected X-range. The Comment input box can be used to enter a text that will be displayed in the plotlegend instead of the default function name.

Figure 5.9: The Add Function... dialog box: Cartesian Coordinates.

If the function expression contains terms that are recognizable as constants, e.g.: f(x) = a*x + b, QtiPlot will detect them anddisplay a two column table on the right side of the dialog which contains input spin boxes that simplify setting appropriate valuesfor the detected constants.

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Figure 5.10: The Add Function... Dialog Box: Automatic Detection of Constants.

A function can also be defined using a parametric definition by selecting "Parametric plot" as the Curve type. That is, given somevariable, m, the (x,y) data points are computed using functions of that variable, x=f(m) and y=g(m).

The first parameter is the name of the parametric variable (here m). It is followed by the definitions of the two functions, therange of the parametric variable, and the number of data points.

Figure 5.11: The Add Function... dialog box: Parametric Coordinates.

Finally, a polar definition of the function may be used by selecting "Polar plot" as the Curve type. Given some variable t, then

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the radius (R) and angle (Theta) are computed using two functions of that variable, R=f(t) and Theta=g(t), in a manner similar tothe parametric function case. The (x,y) data points are then computed as x=R*cos(Theta) and y=R*sin(Theta).

The first parameter is the name of the parametric variable (here t). It is followed by the definition of the two functions, the rangeof the parametric variable, and the number of data points. Note that the angle is in radians. pi is an internally defined constantwhich can be used in any mathematical expression. For example, you can use 3*pi to define the parameter range.

Figure 5.12: The Add Function... dialog box: Polar Coordinates.

5.6 Add Layer

This dialog is opened when you add a new layer on the active plot. If you select Guess, QtiPlot will divide the window in twocolumns and put the new layer on the right. If you choose Top-Left Corner, QtiPlot will create a new layer with the maximumpossible size and locate it on top of existing layers. The new layer contains an empty plotting area. You can subsequently modify

the size and position of each layer by selecting it with the layer number buttons and picking the Layer Geometry commandfrom the context menu.

Figure 5.13: The Add Layer Dialog Box.

5.7 Add/Remove Curves

This dialog is activated by selecting the command Add/Remove Curves... from the Graph Menu.

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The left window shows the columns available from the project’s tables that may be used for plotting. If the Show current folderonly option is checked, only tables from the active folder of the project will be listed in this window. It is possible to sort theavailable tables/folders in alphabetical order by pressing the Available data column header. The right window lists the curvesalready plotted. In the case presented below, there are two tables that the Add/Remove Curves... dialog box lists for the selectionof columns. You select a Y column to plot using this dialog. QtiPlot will use the column defined as X in the corresponding tablefor the X values.

Figure 5.14: The Add/Remove Curves... Dialog Box.

In this dialog box, if you select one curve of the plot in the right window, you can change the columns used for X and Y with thePlot Association button. In any case, you can’t mix the X values from one table with the Y values from another one. If you wantto do this, you have to copy the columns into the same table.

If the curve selected is a function, you can modify it by pressing the Edit Function... button. Refer to the Add Function... dialogbox for more details on functions editing.

If the Show Range option is checked, the plot range of all the curves not defined as analytical functions will be also displayedin the right window of the dialog. The plot range is the interval of points which are visible in a curve. You can show/hide datapoints from a selected curve, without having to delete them, by pressing the Edit Range... button, which opens a dialog allowingto edit the plot range.

5.8 Arrange Layers

This dialog is activated by selecting the Arrange Layers... command from the Graph Menuor by entering Shift-A.

This dialog provides for modification of the geometrical arrangement of plot layers which are already present in the active graphwindow. You can add new layers or remove existing ones using the Number of layers control. Checking the Link X axes optionmakes all the X-axes interdependent, meaning that if you manually set abscissa scale limits on one plot layer, then the samelimits will automatically be set on all other layers in the plot window.

You can specify the number of rows and columns that define a grid of plots. With the default settings, QtiPlot computes the sizeof the layers in the grid from the size of the graph window. If you check the Layer Canvas Size option, you can set the size of thedrawing area for the layers. QtiPlot will then modify the size of the graph window to accommodate them. When the Fixed sizebox is checked, the size of the layers will be kept unchanged when you manually resize the graph window.

The controls in the two group boxes on the right, Alignment and Spacing, are used to set the alignment of the layers in the windowand the margins between the layer borders and the graph window limits. The Spacing group includes an Align control with 2options (Canvases and Layers) that control the meaning of the row and column spacing entries. If the Canvases alignment option

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is chosen, then the spacing fields define the distances between the axes of the layers. On the other hand, if the Layers alignmentoption is chosen, then the spacing fields define the distances between the borders of the layers.

Finally, it is also possible swap two layers using the Swap Layers controls. Simply select the Source and Destination layers andclick the Swap button.

Figure 5.15: The Arrange Layers... dialog: the Geometry Tab

Once suitable choices have been made, clicking on either the Apply or OK buttons will arrange the layers to obtain the desiredalignment of the vertical and horizontal axis.

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Figure 5.16: Example of a vertical arrangement for two plots.

Note that if modifications are later made to an aligned plots, then alignment of the different axes may be lost. Simply re-executeArrange Layers... to again re-arrange the plot.

5.9 Graph Manipulation

This dialog is activated by selecting the Extract to Graphs... command or the Merge Graph Windows... command from the GraphMenu.

If opened with the Extract to Graphs... command, each layer in the currently active graph window is copied into its own, newlycreated, graph window, having the same size as the source graph window. This dialog allows you to decide what happens withthe original graph window. If you uncheck the Keep Source Graph option, then the original window is deleted. If the option FullPage for Extracted Layers is checked, the new layers will be resized to fill their whole graph windows.

Figure 5.17: The Graph Manipulation dialog used for extracting individual layers from 2D graph windows.

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If opened with the Merge Graph Windows... command, this dialog displays a list of 2D graph windows. You may choose todisplay in this list only the graphs from the curently active folder or from the whole project. The list can be sorted alphabeticallyin ascending or descending order by clicking on the Graph column header. All these graph windows will be merged into a newlycreated 2D plot window. You may also choose the graph windows to be merged by selecting the option Specified in the Mergelist box. Also, you may decide what happens to the original graph windows after the merging process. If you uncheck the KeepSource Graph option then the source windows are deleted.

Figure 5.18: The Graph Manipulation dialog used for merging 2D graph windows.

If the OK button is pressed, QtiPlot creates a new graph window and closes this dialog. The Arrange layers dialog pops-up,allowing users to specify the layout of the newly created graph window.

5.10 Line Options

This dialog allows modification of lines or arrows which have been created with either the Draw Arrow (Ctrl-Alt-A) or DrawLine (Ctrl-Alt-L) commands from the Graph Menu. The dialog can also be opened by double clicking on an arrow or line, or byright clicking a selected arrow or line and then selecting Properties... from the resulting pop-up menu. It can also be embeddedinto the Plot details dialog when you select a line/arrow from the list of objects in a 2D plot layer.

5.10.1 Line Tab

The Line tab of the dialog allows changing the color, the style of the line and the line width. Line width is set in pixels. Thechanges you make can be applied to the selected line, to all lines in the plot layer, to all lines in the active window or to all lineobjects from all plot windows, depending on the selection in the Apply to... box.

It is also possible to define a default style for all new lines by clicking the Set Default button.

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Figure 5.19: The Arrow Options Dialog: Line Tab

5.10.2 Arrow Head Tab

The Arrow Head tab is used to modify the shapes of the arrow heads. Length is expressed in pixels and the angle in degrees. Thechanges can be applied to the selected line, to all lines in the plot layer, to all lines in the active window or to all line objects fromall plot windows, depending on the selection in the Apply to... box.

It is also possible to define a default style for the arrow heads using the Set Default button.

Figure 5.20: The Arrow Options Dialog: Arrow Head Tab

5.10.3 Geometry Tab

The Geometry tab is used to specify the starting and ending points of the selected line/arrow. The coordinates can be set as afunction of the scale values displayed on the left (Y) and bottom (X) axes, or in pixels, by choosing the desired method from theUnit pull-down list. Pixel coordinates are relative to the top-left corner of the layer which contains the line.

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Figure 5.21: The Arrow Options Dialog: Geometry Tab

5.10.4 Axes Tab

The Axes tab is used to specify the axes to which the selected line/arrow is attached. The changes can be applied to the selectedline, to all lines in the plot layer, to all lines in the active window or to all line objects from all plot windows, depending on theselection in the Apply to... box.

Figure 5.22: The Arrow Options Dialog: Axes Tab

5.11 Column Options

This dialog is activated by selecting the Column Options... command from the Table Menu. At least one column must be selectedbefore this command can be used.

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Figure 5.23: The Column Options... Dialog.

The checkbox Enumerate all to the right is used to rename of all the columns which lie to the right of the selected column. Forexample, if the name of the selected column is "xyz", then the selected column and all of the following columns will be renamedto "xyz1", "xyz2", and so on.

The "<<" and ">>" buttons change the selected column. The highlighting of the column in the table behind the dialog box willchange indicating that a new column has been selected. The column to which the formatting commands are applied is the onewhose name appears in the "Column Name" box.

The Plot Designation selector is used to define which columns are to be used as X, Y or Z values or as error bars. In a table youcan select several columns as X, in which case the column labels will display as [X1], [X2], etc. Multiple Y columns will displayas [Y1], [Y2], etc. The same scheme is followed for multiple Z columns.

The Alignment selection box is used to define the position of the text in the selected column: it can be aligned with the left orright edge of the column or centered horizontally in the available space.

The Comment box allows entering text that will be displayed in the table header just below the column name when the DisplayComments in Header option is checked.

5.12 Plot Associations

This dialog is activated by selecting the Plot Associations... command from the Format Menu. It may also be activated byright-clicking on a plot curve and selecting Plot Associations.... This dialog is only available if the active plot layer contains datacurves.

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Figure 5.24: The Plot Associations Dialog.

This dialog may be used to select the columns of the table to be used as X, Y and error values for the active curve.

5.13 Edit Curve Range

This dialog is activated by selecting the Edit Range... command from the Format Menu. It may also be activated by right-clickingon a plot curve and selecting Edit Range.... This dialog can be opened only if there is a selected data curve in the active plot layer.

Figure 5.25: The Edit Curve Range Dialog.

This dialog may be used to select the visible data range for the active curve.

5.14 Plot Details

This dialog is activated by selecting the Plot... command from the Format Menu. It may also be activated either by a double clickon a plot or by right-clicking on a plot and selecting Plot Details.... If there is more than one layer in the window, QtiPlot willselect the layer which contains the plot under the mouse pointer. The exact contents of the dialog will vary depending upon howthe dialog was invoked and on the type of plot item selected.

The left part of the dialog window is a tree view that shows the plot layers in the active window and the curves and objects whichare plotted on each layer. All modifications will be made to the selected item (window, layer, curve or plot object). The right partof the dialog box contains several tabs which depend on the kind of item selected in tree view on the the left side of the dialog.They are described in the following subsections.

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If the selected item is a plot curve than the Table, Plot Associations... and Edit Range... buttons become visible. Clicking the PlotAssociations... button opens a dialog which can be used to select the columns of the table to be used as X and Y values for theactive curve. Clicking the Edit Range... button opens a dialog which can be used to change the visible data range for the activecurve. If the Table button is visible, it may be used to access to the table which contains the columns for the selected curve.

5.14.1 Dimensions

In the Dimensions tab you can accurately set the position and size of the graph window. The size can be applied to either theselected window or to all graph windows in the project. When the Keep aspect ratio option is checked, changing either thewidth or height will proportionally change the other dimension. It doesn’t mean that the aspect of the graph window will remainunchanged when you manually resize it with the mouse. If you want to enable this fixed aspect behaviour for the graph layers,you need to visit the layer geometry tab. You should use the preferences dialog if you want to change the default behaviour forall plot layers that will be created in the future.

If the option Do not resize layers when window size changes is checked the size and position of the plot layers will remain fixedwhen the user changes the dimensions of the window.

Figure 5.26: The Plot Details Dialog: Dimensions tab.

5.14.2 Print

A graph page with dimensions that are smaller or larger than those of the printable area will be printed scaled to the dimensionsof the printer page if the Scale layers to paper size option is checked.

Select the Print Cropmarks check box to display crop marks at the margins of the printer’s printable area.

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Figure 5.27: The Plot Details Dialog: Print tab.

5.14.3 Fonts

Using the push buttons in the Fonts tab you can customize with just a few clicks the fonts for various elements of all plot layersin the graph window.

Figure 5.28: The Plot Details Dialog: Fonts tab.

5.14.4 Miscellaneous

By checking the Link X axes option in the Miscellaneous tab, the layers in the graph window will be linked: when changing theX axis scale in one layer the X scales in the other layers will be adjusted accordingly. This behavior can be applied to the activewindow or to all graph windows in the project.

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Figure 5.29: The Plot Details Dialog: Miscellaneous tab.

5.14.5 Window Display

In the window Display tab you can define the style for the background of the graph window page. By default it is filled with asolid white color, but you can set it to be filled with a color gradient. By pressing the Set As Default button these settings will beautomatically applied to all graph windows created in the future.

Figure 5.30: The Plot Details Dialog: Display tab.

5.14.6 Legends/Titles

The Legends/Titles tab provides controls for automatic legend and title construction in QtiPlot graphs.

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You can use the Translation Mode %(1), %(2) drop-down list in the Legends group box to specify the table column headerinformation that should be used in the graph legend. The second Translation Mode drop-down list in the Auto Axis Titles box hasthe same utility with respect to the graph axis titles.

If the Auto-update box is checked, plot legends are updated each time a curve is added or removed from the plot layer the legendsbelong to. By pressing the Set As Default button these settings are saved to the user preferences and reused each time you createa new 2D plot window.

Figure 5.31: The Plot Details Dialog: Legends/Titles tab.

The Data Plot Index control is useful when plotting multiple Y columns of data against a single X column. You can use it inorder to specify which data column will provide the information for the axis titles. You should be aware that when choosing thedata column based on this index QtiPlot takes into account the number of curves attached to each layer axis.

If the option Show Units (when available) is selected the contents of the table column’s Unit property will be appended to theaxis title. All these settings can be applied to the active graph or to all 2D plot windows in the project, depending on the optionyou choose in the Apply to... list box on the right side of this dialog tab.

The following tabs are available when an item corresponding to a plot layer is selected in tree view on the the left side of thedialog:

5.14.7 Layer

In the Layer tab you can define the style properties of the plot layer: the background color/gradient and the frame around it. Youcan also customize the behavior of the plot layer: enable/disable Antialiasing for the drawing of data curves, Autoscaling of theaxes range when the data curves are modified and automatic resizing of the fonts when the size of the plot layer is changed bythe user (Scale Fonts check box).

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Figure 5.32: The Plot Details Dialog: Layer properties.

5.14.8 Canvas

In the Canvas tab you can define the properties of the plot canvas: the background color/image and the frame around the canvas.

Figure 5.33: The Plot Details Dialog: Canvas with a solid background color.

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Figure 5.34: The Plot Details Dialog: Canvas with a background image.

5.14.9 Geometry

The third tab defines the geometry of the drawing canvas in a plot layer. When the Keep aspect ratio option is checked, changingeither the width or height will proportionally change the other dimension. Also, the ratio between the width and the height of theplot canvas will remain unchanged when you manually resize the graph window.

Figure 5.35: The Plot Details Dialog: Canvas geometry.

5.14.10 Speed

The Speed tab can be used to customize the speed mode for the layer. This can be very useful when dealing with very large datasets. Speed mode uses the Douglas and Peucker algorithm, the purpose of which is to take a ’curve’ composed of line segments

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(or points) and find a new curve with fewer points that is not too dissimilar from the original curve. The algorithm defines ’nottoo dissimilar’ as a function of the maximum distance (tolerance) between the original curve and the new curve. The new curvethen consists of a subset of the line segments (or points) that defined the original curve. When the speed mode is enabled, filteringof the data is activated only for the curves with more than the specified maximum number of data points.

Figure 5.36: The Plot Details Dialog: Layer Speed Mode.

5.14.11 Layer Display

The layer Display tab can be used to customize the display options for the plot layer.

The Data Drawing Options group box enables fine control over the way data is drawn on the plot canvas. If the Margins box ischecked QtiPlot automatically adds some amount of space before and after the data values along each axis scale. The effect ofthis option is mainly visible when creating new plots from table columns or when rescaling a plot layer so that all data on thegraph is visible, using the Graph -> Rescale To Show All command.

Using the controls in the Drop Shadow group box it is possible to enable/disable the display of a drop shadow effect for all curvesin a plot layer. The drawing options for the drop shadows are the color (by default it is set to dark gray), the offset (8 pixelsby default) and the blur radius (5 by default).It is also possible to show/hide the drop shadow of individual plot curves via theircontext menu (right-click on a plot curve in order to make it pop-up).

The controls in the Axes group box can be used to enable/disable the display of individual plot axes.

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Figure 5.37: The Plot Details Dialog: Layer Display.

5.14.12 Stack

The Stack tab can be used to customize the vertical offset between data curves. The following stacking modes are available:

None: Data plots are not stacked.

Cumulative: Y values of data plots are stacked cumulatively.

Constant: Data plot points are shifted by a specified constant value that can be set in the edit box to the right of the Constantradio button.

Auto: This is the default mode. QtiPlot calculates constant offsets based on min-max Y value difference and a specified gap.The gap value can be set in the edit box to the right of the Auto radio button.

Individual: Each plot has individual offset settings, which can be modified on the Offset tab in the plot details dialog when thecorresponding plot curve is selected in the left panel under the expanded Layer icon.

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Figure 5.38: The Plot Details Dialog: Layer Display.

5.14.13 Group Edit

The Group Edit tab can be used to customize the appearance of all plot curves with only a few clicks. This is mainly helpfulwhen you have a lot of data curves and you want to avoid individually editing curve style properties.

The Line Color push button in the Increment Curve Properties box is intended to be used in conjunction with the Indexed Colorslist defined in the Curves tab of the Preferences dialog. By pressing this button, the line colors of all the data curves in the currentplot layer will be changed according to their indices in this list of colors. The other two buttons Line Style and Pattern will changethe line style and the fill patterns respectively. Please beware that by pressing the Pattern button the area bellow the curves willbe automatically filled, even if it wasn’t before.

Figure 5.39: The Plot Details Dialog: Group Edit tab.

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The Gradient Fill box adds the possibility to apply a colour gradient to all plot curves. The line color, fill color and symbol colorof all the data curves will be changed to a color in the user defined range going from Color 1 for the first curve of the plot layerto Color 2 for the last curve. This change can be applied to the current plot layer or to all the layers in the current graph windowas well as to all 2D graph windows.

The same functionality can be accessed via the context menu of a layer (right-click on the layer canvas to make it pop-up). Theimage bellow shows the Palette sub-menu that can be used to set a gray scale gradient or a default color gradient from a red Color1 to a blue Color 2. You can also apply the Indexed Colors default list defined in the user preferences. The Style sub-menu givesaccess to the Increment Line Style and Increment Fill Pattern functions explained above.

Figure 5.40: Context menu of a plot layer.

5.14.14 Curve axes

The Axes tab, the first tab on the right side of the dialog window, allows definition of the pair of axes to which a curve is attached.Attaching different curves on the layer to different X/Y axis pairs permits placing several curves with different x/y scales on thesame plot layer.

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Figure 5.41: The Plot Details Dialog: Assign Axes.

5.14.15 Line/Pattern

The title of this tab may be either Line or Pattern depending on the type of the selected plot curve. This tab allows customizingthe style of the plot line (color, line style, thickness). The connect button allows changing the style which is used to draw theselected curve (steps, droplines, etc). See the Plot menu to see the different types of plots available.

Figure 5.42: The Plot Details Dialog: Line formatting.

5.14.16 Symbol

The Symbol tab can be used to select the plot symbol used for the data points and to modify its aspect (size, color, fill color,transparency). There are three categories of plot symbols available in QtiPlot: Standard, Unicode and Image symbols and youcan choose one of them by clicking the corresponding radio button from the top side of this tab. Each category of symbols hasits own customizable properties.

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The Size drop-down list box may be used to select either a column that contains the size values for the plot symbols or a constantvalue. Alternatively you may type a custom constant size value. Units are measured in pixels. If the size values are taken from atable column, the Scaling Factor box becomes visible and its value may be used to proportionally increase or decrease the sizesof the plot symbols.

Figure 5.43: The Plot Details Dialog: Standard Symbol formatting.

If the the shape of the symbol is an ellipse (a circle in fact), the Size based on combo box becomes visible. It lets you choosehow the area of the symbols is determined by the value selected/typed into the Size combo box. Three options are available:.

Square: The area is calculated as the area of the square enclosing the circle: A = Size*Size.

Diameter: The diameter of the circle equals the value defined for Size, the area being calculated as: A = Pi*Size*Size/4.

Area: The area of the circle equals the value defined in the Size box: A = Size.

The Edge Color, used to draw the shape of the symbol, as well as the Fill Color, may be either an individual RGB color that youcan select from a table by pressing the color button or a color map based on the values stored in a table column. In the second caseQtiPlot creates evenly sized ranges of values between the minimum and maximum values of the column selected in the combobox and associates a color with each range of values. The color of the symbol is determined by finding the color associated withthe column value into this color map. By pressing the edit button the Custom Color Map dialog pops-up, allowing to customizethe default color map.

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Figure 5.44: The Plot Details Dialog: Unicode Symbol formatting.

The Original size button is available only if the symbol is an Image. This button is automatically enabled when the current sizeof the plot symbols is different from the original image size. If pressed, the current size settings are reverted to the original imagesize.

Figure 5.45: The Plot Details Dialog: Image Symbol formatting.

5.14.17 Labels

The Labels tab is used if you want labels plotted at each data point in the plot. Options are provided to control the font, color,rotation angle and position of these labels.

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Figure 5.46: The Plot Details Dialog: Labels formatting.

5.14.18 Offset

The Offset tab is only available when the plot layer has the Individual stacking mode enabled. It may be used to specify customoffsets for the plot curves in both horizontal and vertical directions.

Figure 5.47: The Plot Details Dialog: Offset formatting.

5.14.19 Error bars

With the controls in the Direction group you can specify if the positive and/or negative side of the error bars should be drawn, bychecking the Plus and/or Minus boxes. You can also specify if the error bars are horizontal or vertical by checking/unchecking

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the X Error Bar box.

Using the controls in the Style group box you can customize the error bars in terms of color, line width, cap width and trans-parency. Finally, it is possible to tell QtiPlot to skip a number of data points when drawing the error bars by specifying a positivevalue in the Skip Points box.

Figure 5.48: The Plot Details Dialog for formatting error bars.

5.14.20 Pie plots

These commands are available for pie plots. The first tab is used to customize the pie segments. The fields on the left are used tomodify the border drawn around each segment. The color, type and width of line may be customized. The default is no border(line width = 0).

The fields on the right are used to define the fill style used for pie segments. The First color combo-box defines which color isused for the first segment. The remaining segments will be filled with colors that follow the order defined in the combo-box’slist. The default value for this field is black, so segments 2, 3, ... will be red, green, etc.

The Pattern combo-box defines the fill pattern that will be used for all segments of the pie. The default value is solid fill.

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Figure 5.49: The Plot Details Dialog for pies: Pie Segment Formatting.

5.14.21 Pie geometry

Figure 5.50: The Plot Details Dialog for pies: Pie Geometry.

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5.14.22 Pie labels

Figure 5.51: The Plot Details Dialog for pies: Pie Labels Formatting.

5.14.23 Box/Whiskers

Figure 5.52: The Plot Details Dialog for box: Whiskers Formatting.

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5.14.24 Percentile

Figure 5.53: The Plot Details Dialog for box: Percentile Formatting.

5.14.25 Data

The Distribution Curve control group makes possible to overlay a "pseudo" distribution curve on the binned data by selectingNormal, Lognormal, Poisson, Exponential, Laplace, Lorentz, Weibull, Kernel Smooth, Gamma or Binomial from the Type drop-down list. We call these curves "pseudo" distribution curves because they are not the result of a fit operation performed on thebinned data. QtiPlot simply determines the data mean, then overlays the curve so that the means coincide. In the case of atwo parameter distribution, the second parameter taken into account is the standard deviation of the binned data. If the Scale toMaximum box is checked an input value box becomes visible, allowing you to control the amplitude of the distribution curve.

If you click the Show Statistics button from the Bin Worksheet control group, QtiPlot creates a table containing the computedquantities of the bins and the dialog is closed. You may check the Add Distribution Curve option in order to add the data used tocreate the overlayed distribution curve to this bin table.

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Figure 5.54: The Plot Details Dialog for box: Data Formatting.

5.14.26 Spacing

Figure 5.55: The Plot Details Dialog for histograms: Spacing Formatting.

5.14.27 Histogram Data

The Distribution Curve control group makes possible to overlay a "pseudo" distribution curve on the binned data by selectingNormal, Lognormal, Poisson, Exponential, Laplace, Lorentz, Weibull, Kernel Smooth, Gamma or Binomial from the Type drop-down list. We call these curves "pseudo" distribution curves because they are not the result of a fit operation performed on thebinned data. QtiPlot simply determines the data mean, then overlays the curve so that the means coincide. In the case of a

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two parameter distribution, the second parameter taken into account is the standard deviation of the binned data. If the Scale toMaximum box is checked an input value box becomes visible, allowing you to control the amplitude of the distribution curve.

If you click the Show Statistics button from the Bin Worksheet control group, QtiPlot creates a table containing the computedquantities of the bins and the dialog is closed. You may check the Add Distribution Curve option in order to add the data used tocreate the overlayed distribution curve to this bin table.

Figure 5.56: The Plot Details Dialog for histograms: Data Formatting.

5.14.28 Line

This tab is only available when the selected data curve is a box curve or a histogram that also displays a distribution curve. Itallows customizing the style of the distribution curve (color, line style, thickness).

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Figure 5.57: The Plot Details Dialog: Distribution Curve Line formatting.

5.14.29 Vector

The value typed in the Length spin box determines the length of the arrowheads. Units are measured in points. The Angle valuedetermines the arrowhead angles in degrees. You may check the Filled box to display filled arrowheads or uncheck it in order todisplay the hollow (transparent) arrowheads.

If the vector type is XYXY the End Point controls group is visible and you can select the column that contains the X end pointvalues from the X End drop-down list and the column that contains the Y end point values from the Y End drop-down list.

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Figure 5.58: The Plot Details Dialog for Vector XYXY curves.

If the vector type is XYAM two other control groups become visible: Vector Data and Magnitude.

Figure 5.59: The Plot Details Dialog for Vector XYAM curves.

The Angle drop-down list box from the Vector Data controls group may be used to select either a column that contains the vectorangle values or a constant value. Alternatively you may type a custom constant angle value from 0 to 360 degrees. The angle ismeasured counterclockwise.

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The Magnitude drop-down list box from the Vector Data controls group may be used to select either a column that contains themagnitude values or a constant value. Alternatively you may type a custom constant magnitude value. Units are measured eitherin pixels or in real world coordinates (Scale Coordinates), depending on the value selected in the Unit drop-down list box fromthe Magnitude controls group.

The Multiplier value from the Magnitude controls group may be used to proportionally increase or decrease the length of thevectors. For example, type 0.5 to draw the vectors at half their original length. The default value is 1.

Finally, it’s worth mentioning that you may change the vector type from XYXY to XYAM and vice versa using the Plot typedrop-down list box from the bottom left corner of this dialog.

5.14.30 Values

This tab is activated by clicking on a contour curve (or on the plotting area) when a 2D plot has been created from a matrix withone of the following commands from the Plot 3D menu: Contour+Color Fill command, Countour Lines command or Gray ScaleMap command.

Figure 5.60: The Values tab.

The Values tab allows choosing the matrix that is to serve as the data source for the plot. It is possible to use a formula definedfor the matrix to calculate the plotted Z values by checking the Use matrix formula to calculate values box. This results in higheraccuracy, especially when drawing contour lines, but it only works if the formula uses muParser compatible syntax.

If you need higher accuracy but the source data matrix can not use an analytical formula to calculate its values you can use thecontrols from the Resolution group box. There you can define a larger number of Columns/Rows and press the Resample button.By doing this the dimensions of the source data matrix will be increased. The values of the new data cells are calculated usingbilinear interpolation.

By pressing the x2 button the dimensions of the source matrix are doubled, the values of the new data cells being calculated usingthe bilinear interpolation method. The /2 button performs the opposite operation: the dimensions of the data source matrix aredivided by two. It is possible to revert all the changes in resolution by pressing the Undo button.

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5.14.31 Colors

Figure 5.61: The Colors tab.

There are two groups of controls on this tab. Each group is activated by checking the box next to the group label. The first groupof controls, labeled Image, are used to select the fill type of the contour plot. It is checked when filling of the contour plot isdesired. If unchecked, no fill will be used. If filling is enabled, you may choose between gray-scale, a default color mapping anda custom color mapping with the 3 radio buttons. The default gray-scale and color maps are shown in the figure below.

You can only customize the colormap when the Custom Colors option is selected. A table with a set of numbers (the Z levels),and the color corresponding to each Z level, is presented. You can then add, remove or modify levels from the definition of thecolormap. Note that this is only the definition of the colormap - it won’t change the number of contour lines in your plot.

A click on the Level column header opens a dialog alowing to quickly edit the color map levels by specifying their total numberand an intensity range from Minimum to Maximum.

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Figure 5.62: Set Equidistant Levels dialog box.

A click on the Color column header opens a dialog alowing to quickly customize the colors in the map by specifying the Fromand To colors and a color policy (Two Colors or Custom Color Map).

Figure 5.63: The Two Colors mode of the Gradient Fill dialog box.

Figure 5.64: The Custom Color Map mode of the Gradient Fill dialog box.

An example of classical custom colormap is given here:

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As long as the Scale Colors checkbox remains checked, Z-values that fall between colormap levels will be displayed in colorsthat are interpolated between the colors defined for the bounding levels. It is also possible to define discrete colors for each level.To do this you must uncheck the Scale Colors checkbox. In this case, no interpolation will be done, and you must define enoughlevels in your colormap to produce a desirable result.

The second group of settings must be enabled if you want a bar scale on your plot. You can then define its position and width.

5.14.32 Contour Lines

The Contour Lines tab is used to customize settings applicable to the contour lines. You can select the number of lines and theircolor. If you check Use Default Pen, the color of the lines will be defined by the settings in the group of controls to the left ofthe checkbox. If you check Use Color Map, the lines will be colored as a function of the Z levels from the colormap defined inthe Colors setting tab. If you check Use Table Custom Pen, the color of the lines will be determined by the settings defined in thePen column of the table displaying the Z levels.

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Figure 5.65: The Contour Lines tab.

Figure 5.66: The Labels tab.

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The Labels tab is used to enable/disable the display of a Z value for each of the contour lines. You can globally customize thecolor, background, font, rotation and position of the text labels.

5.14.33 Analysis

Figure 5.67: The Plot Details Dialog for curve analysis operations.

The Analysis tab is available only for plot curves that are the result of an analysis operation (also called an analysis filter). Thistab allows to access and edit the properties of the analysis object attached to the plot curve. It also makes possible to remove theanalysis filter by clicking the Delete button.

The Edit... button on the right side of this tab closes the current dialog and opens a new dialog that allows to modify the propertiesof the analysis object. Generally it is the same dialog that was used in order to perform the analysis operation. Please note thatnot all operations can be edited and if this is the case for the current one the Edit... button is disabled.

By clicking the Copy button the analysis operation is stored to memory and can be applied later on to any other data curve fromany plot layer by right-clicking on it and selecting the action Paste Operation from its pop-up context menu.

For all analysis operations there is a mechanism available in QtiPlot that allows to trigger a recalculation when the data source ismodified. It is possible to specify the desired recalculation mode using the Recalculate list box. The available options are:

No - No recalculation when data changes.

Auto - A recalculation is automatically performed when input data changes.

Manual - No recalculation is triggered when data changes, instead the user can perform a recalculation at any time by pressingthe Recalculate button.

The complete name of the column which is the data source for the operation, as well as the data range are indicated in the Datasettext box. By clicking the Go to Column button the table window that contains this column is activated and the source column isselected.

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If the analysis operation is a data fit operation an additional set of controls are available: the Parameters Table and the CovarianceMatrix text boxes and their corresponding Go to Window buttons. By clicking any of the Go to Window buttons the correspondingtable/matrix window is activated if it already exists, otherwise it will be created using the name provided in the text box.

All the functionality provided by the controls in this dialog tab can be accessesd by right-clicking on a plot curve and selectingthe Analysis item from the pop-up context menu.

Figure 5.68: Context menu for a Lorentz data fit analysis operation.

5.15 Define surface plot

This dialog is used when you enter the New -> New Function Plot -> New 3D Surface Plot... command. It allows for thecreation of a new function of two variables. When the "Function" Surface type is selected the coordinate system will be Cartesianand the function will be of the form: z = f(x,y).

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Figure 5.69: The New -> New Function Plot -> New 3D Surface Plot... dialog box.

You may also define the X, Y and Z scales and the mesh parameters.

You can create parametric surfaces when the "Parametric" Surface type is selected. The only parameters allowed are latitude andlongitude: u and v. Here, for example, is how you might plot a sphere having a radius equal to one:

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Figure 5.70: The New -> New Function Plot -> New 3D Surface Plot... dialog box.

As in the case for functions, you can supply the drawing domain for the two angular parameters and you can define the meshparameters. The more rows/columns you request, the better the resolution of the output image will be. However, this is at thecost of a larger memory consumption and an increased time of computation. A slow CPU and small amounts of memory will belimiting.

Finally, you can provide information to the drawing routines about the rotational symmetry of the parametric surface using thetwo Periodic check box options (one for each parameter).

5.16 Export Graph Dialog

This dialog is activated by selecting the Export Graph command from the File Menu. The command appears in the file menuwhenever a graph window is selected.

The file Name as well as the Path where the image will be saved can be chosen by pressing the file system browsing buttons atthe right. They can also be edited manually. Please note that QtiPlot provides an auto-completion mechanism when editing thefile path.

All graphs, or one graph at a time, can be exported in any of the available image formats. Depending upon the image formatchosen, you may be able to customize various image file parameters as well as the size of the exported image.

For the .bmp, .pbm, .jpeg, .xbm, .pgm, .ppm image formats, the only available option is the quality of the image. This parameterdefines the image compression ratio, and may be set to any value between 1 and 100%. Higher values produce a better qualityimage and a larger file, while lower values result in increasingly lossy compression, degraded image quality, and smaller file size.For .png, .tiff and .xpm, there is an option to choose a transparent background.

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For .eps, .pdf and .ps file formats, the option dialog is different, see screenshot bellow. If the option Export as embedded imageis checked, the output file is only a wrapper around a raster image of the 2D plot layer/window. For a real vectorial output thisoption should be unchecked.

In the case of a vectorial output, the Native fonts option becomes available. If checked, the text strings that contain only charactersfrom the Code Page 1252 Windows Latin 1 (ANSI) will be exported as text objects, all other text strings being converted to pathsand exported as drawing objects. The number of native text fonts is limited to the standard fonts provided by the PostScript andPDF formats (Times, Helvetica and Courier with their bold and/or oblique/italic variants). If the Native fonts option is uncheckedall text strings will be converted to drawing paths.

When exporting the plot to LaTeX (.tex) there are two very useful options: Export font sizes and Escape special characters intexts. If checked, the first option will include LaTeX commands in the output which keep the original font sizes. If not checked,the font size specified in the preamble of the TeX document will be used for all text strings in the plot. The second optionspecifies whether LaTeX special characters ($ _ { } ˆ % #) should be escaped or not when exporting. If the title or the axis labelscontain LaTeX syntax (like superscripts, subscripts, etc...), and you want them to be interpreted by the LaTeX compiler, you mustuncheck this option.

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By default the plot is exported to its real size on screen, but if you wish, you can choose a different size by checking the Customprint size box. In addition, there is a Keep aspect ratio option. If you check this box and modify one dimension of a plot, theother dimension will automatically be modified to keep the plot’s aspect ratio the same.

When exporting multi-layer 2D plot windows the option Clip space around layers is also available. If this option is checkedQtiPlot uses the bounding rectangle of the layers to calculate the size of the exported image. Otherwise the size of the image isequal to the interior size of the graph window (the frame and the title bar of the window being excluded).

When exporting 3D plot windows to a vectorial image format (.eps, .pdf, .ps, .pgf or .svg) the option Export 3D texts as becomesavailable, allowing to choose the output method for texts. If this option is set to Bitmap images all text strings will be exported asraster images embedded in the output file. If you choose the Native fonts method the number of available text fonts is limited tothe standard fonts provided by the PostScript and PDF formats (Times, Helvetica and Courier with their bold and/or oblique/italicvariants). If the LaTeX file method is used, the texts are not be included in the output file, instead QtiPlot generates an extra .texfile, having the same base name and containing all the text strings from the 3D plot window, with their exact positions, colorsand font sizes. By compiling this .tex file using a locally installed LaTeX compiler it is possible to get a vectorial output imagethat includes your custom fonts.

It is also possible to export animated 3D plot windows to .avi movie files. In this case there are three options available: the totalnumber of Frames, the Frame Rate (which is the number of frames per second) and the Image quality. Internally QtiPlot exportseach animation frame as a JPG image.

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5.17 Fast Fourier Transform Dialog

The FFT... dialog box can be used on a plot, on a table or on a matrix. It is used to compute either the direct or inverse FFT. Seethe FFT section in the Analysis chapter for an example.

Figure 5.71: The FFT... dialog box for a curve.

QtiPlot will create a new plot window containing the FFT amplitude curve, along with a new table which contains the real part,the imaginary part, the amplitude, and the phase of the FFT.

If the Normalize Amplitude check box is on, the amplitude curve is normalized to 1. If the Shift Results check box is on, thefrequencies are shifted in order to obtain a centered x-scale.

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Figure 5.72: The FFT... dialog box for a table.

When performing an FFT on a table, you must select the sampling column (X-values) and one (for simple real values) or two (forcomplex values) columns of Y-values. Complex numbers have the real part of the Y-values in the first column and the imaginarypart of the Y-values in the second column. If Y-values are simple reals, you don’t have to select a column for the imaginary part.You can leave the combo box for the second column empty in this case.

By default, the Sampling Interval corresponds to the interval between X-values. Giving a smaller value makes no sense, but youcan increase this value in order to sample fewer values.

On matrices QtiPlot performs a two dimensional FFT using two sampling intervals: one that corresponds to the interval betweenthe X-values and a second one corresponding to the interval between the Y-values. For more details about the two dimensionalFFT please read the following article by Paul Bourke: http://paulbourke.net/miscellaneous/dft/.

Figure 5.73: The FFT... dialog box for a matrix.

If the dimensions of the input matrix are not powers of 2, you have the option to resize it for a more efficient FFT, by checkingthe box Zero-pad to nearest power of 2 size. The new dimensions are calculated to be the closest powers of 2 from the initialdimensions of the matrix and the extra data values used for the FFT are set to zero.

As the result of the FFT operation on a matrix QtiPlot creates a new matrix window containing the amplitude of the FFT, alongwith two other matrices which contain the real and the imaginary parts of the FFT.

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5.18 FFT Filter Dialog

The FFT Filter Dialog can be used on a plot or on a matrix. When the active window is a 2D plot this dialog can be used toapply a one dimensional FFT filter to any of the curves in the active plot layer, see the filtering section for more details.

If the filter type is set to Low Pass FFT Filter QtiPlot removes all the frequencies above a cut-off frequency from the input signal,while keeping the other frequencies unaltered. You can select the cut-off frequency of the filter using the Frequency cutoff inputbox.

Figure 5.74: The FFT Filter -> Low Pass... dialog.

If the filter type is set to High Pass FFT Filter QtiPlot sets to zero all the frequencies below the specified cut-off frequency. Youcan decide if the DC offset (zero frequency) should be kept or not in the filtered signal by checking the Keep DC Offset box.

Figure 5.75: The FFT Filter -> High Pass... dialog.

If the filter type is set to Band Pass FFT Filter QtiPlot cuts both high and low frequencies present in an input signal. You canselect the curve to filter and both the low and high cutoff frequencies of the filter. Also, you can decide if the DC offset (zerofrequency) should be kept or not in the filtered signal by checking the Keep DC Offset box.

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Figure 5.76: The FFT Filter -> Band Pass... dialog.

If the filter type is set to Band Block FFT Filter QtiPlot removes a band of frequencies from a signal while leaving thosefrequencies above and below the stop band. You can select the curve to filter and both the lower and upper stop-band frequenciesof the filter. Also, you can decide if the DC offset (zero frequency) should be kept or not in the filtered signal by checking theKeep DC Offset box.

Figure 5.77: The FFT Filter -> Band Block... dialog.

After performing the operation QtiPlot creates a new table containing the filtered data, and adds a new curve to the current layer.The curve is a plot of the filtered data.

If the active window is a matrix the FFT Filter Dialog can be used to apply a two dimensional FFT filter, for more details seethe following article by Paul Bourke: http://paulbourke.net/miscellaneous/imagefilter/.

Figure 5.78: The FFT Filter Dialog dialog box for a matrix.

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Please note that the input matrix will be modified in order to store the filtered data, but you can revert all the changes by pressingthe Undo button.

5.19 Find Peaks Dialog

This dialog box is opened when you select the Peaks... command from the Analysis menu. By pressing the Find button QtiPlotperforms a search on the selected curve using the first derivative method. This method is based on the fact that the first derivativeof a function at a local extreme point is equal to zero. Only positive peaks are taken into account. The limits of the search rangecan be specified via the From Xmin and To Xmax input boxes.

The Filter Height can be used to specify the minimum height of the found peaks. It is defined as follows: if it is set to zero thestandard deviation of the data is used as a threshold height else it is a percent of the maximum value of the dataset.

It is possible to specify the method to smooth the derivative of the spectrum data. The available methods are:

1. None: Do not use any smoothing method.

2. Savitsky-Golay: Specifies the Savitsky-Golay method to get smooth the derivative.

3. FFT: Specifies the FFT Filter method to smooth the derivative.

4. Moving Window Average: Specifies the Moving Window Average method to smooth the derivative.

Figure 5.79: The Find Peaks dialog box.

In the Display group select the Center check box to mark the center of the peaks. The color of the plotted peaks can also bespecified.

Select the Labels check box to display labels on the data plot for each peak found. It is possible to select the type of center labels:

1. X: Use the X coordinates of the peak centers as center labels.

2. Y: Use the Y coordinates of the peak centers as center labels.

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3. Row Indices: Use the indices of the peaks as center labels.

4. (X,Y): Use the X and Y coordinates of the peak centers as labels.

Use the Rotate -90 check box to specify whether or not to rotate the center labels.

5.20 Frequency Count Dialog

This dialog is activated by selecting the Frequency Count command from the Analysis -> Descriptive Statistics menu. It can beused in order to calculate the frequency distribution of the data values from a table column.

Figure 5.80: The Frequency Count dialog.

Internally QtiPlot sorts the input data and detects the minimum and the maximum values which are displayed in the FromMinimum and To Maximum input boxes. Then it creates a set of bins in this range using the bin size specified in the Step Sizebox. When pressing the Apply button QtiPlot counts the number of times a data value falls within a bin. Data values equal tothe low-edge of a bin are included in the bin while values equal to the upper-edge of the bin are excluded from it, but they arecounted in the next bin (if any).

The results are placed in a newly created table which contains four columns with a row for each bin. The values displayed inthese rows are: the center value of the bin, the upper limit of the bin, the frequency count for the bin and the cumulative frequencyup to that bin, respectively.

5.21 Baseline Dialog

This dialog is activated by selecting the Subtract -> Baseline command from the Analysis menu. With its help it is possible tocreate and subtract a baseline from your data curves.

By pressing the Create Baseline button the number of baseline anchor points specified using the Points box are generated auto-matically or manually and then connected with an interpolation curve or with a custom function. The automatically generatedanchor points equally spaced.

Figure 5.81: The Baseline dialog.

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There are three methods available for the creation of the anchor points of the baseline curve:

1) Interpolation: Curve data points are interpolated using one of the three available methods (Linear, Cubic and Non-roundedAkima).

2) User Defined Equation Y =: The anchor points are calculated using a custom analystical function Y = f(x).

3) Existing Dataset: Finally if you already have the coordinates of the baseline anchor points you can use them by indicatingthe table column where the dataset is stored.

After the creation of the baseline you can modify the position of the anchor points by pressing the Modify button. You can set thenew positions by simple drag-and-drop using the mouse pointer. Precise positioning of the anchor points can be achieved usingthe arrow keys (Left and Right arrows change the point to modify Up and Down arrow keys move vertically the point). It is alsopossible to use the numeric keypad which define a sort of compass rose:

1. 8-key: North

2. 9-key: North-East

3. 6-key: East

4. 3-key: South-East

5. 2-key: South

6. 1-key: South-West

7. 4-key: West

8. 7-key: North-West

Finally by pressing the Subtract button the baseline data is subtracted from your spectrum. This operation can be undone usingthe Undo Subtraction button.

5.22 Integration Options

This dialog box is opened when you select the Integrate... command from the Analysis menu. The dialog displays a different setof controls depending if you are integrating data from a table or from a plot curve.

Figure 5.82: The Integration Options dialog box for curves.

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Figure 5.83: The Integration Options dialog box for tables.

Pressing the Integrate button performs a numerical integration using the trapezoidal method. The result of the integration is listedin the Log Panel.

If the Sort data option is checked the data is sorted before performing the integration with respect to the X values associated tothe input columns or to the abscissas of the curve to be integrated. This option is not available if the input data columns comefrom a table window without any designated X column. In this case the input data is assigned by default with ascending X values.

By checking the Show plot option a new graph window will be created containing a plot of the integrated curve, the data forwhich is stored in a new (hidden) table. QtiPlot stores the integration operation into this output graph window if the Recalculateoption is other than No. By setting this option to Auto any modification of the input data will trigger a recalculation of the valueof the integral.

5.23 Integrate Function Dialog

This dialog box is opened when you select the Integrate Function... command from the Analysis menu Pressing the Integratebutton performs a numerical integration of a user defined analytical function. This function is entered/edited in the Function textbox. A combo box which lists internally defined functions is provided. Clicking the "Add" button will copy the selected functioninto the Function text box at the position of the text cursor. Clicking the "Clear" button will clear the entire contents of theFunction text box. Clicking on the button displaying a pencil icon opens a dialog which contains a combo box that lists recentlyused functions. Selecting one of these and clicking "OK" will replace whatever is in the Function text box with the selectedfunction. The second input field displays the name of the independent variable of the function (i.e., the variable of integration). Itis set to X by default. The third parameter is the maximum number of subintervals that that the integration algorithm may use tointegrate the function. The default value of 1000 should work in almost all circumstances. The fourth parameter is the tolerancelimit. Smaller numbers will result in the algorithm using more subintervals. The default value of 0.01 should work for mostfunctions. The next two fields are the lower and upper limits of integration. Set these to whatever values you need. The final itemis the Plot Area check box. Leave this checked if you want a plot of the integrated function to be drawn on the currently activelayer. A table of the plotted data can be generated by right clicking on the curve and selecting the Worksheet command.

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Figure 5.84: The Integrate Function... dialog box.

The numerical result of the integration will be listed in the Log Panel.

5.24 Polynomial Fit Options

This dialog box is opened when you select the Fit Polynomial... command from the Analysis menu. It allows to choose the curveto fit, the order of the polynomial function to use, the number of points of the resulting curve and the abscissa limits for the fit.

It is also possible to specify how the fit operation responds to modifications of the source data curve using the Recalculate listbox. The available options are:

No - No recalculation when data changes, the fit object is deleted from memory when the operation ends.

Auto - A recalculation is automatically performed when input data changes.

Manual - No recalculation is triggered when data changes, instead you can perform a recalculation at any time by pressing theRecalculate button from the Analysis tab of the plot details dialog.

The recalculation mode can be changed later on via the Analysis tab of the plot details dialog.

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Figure 5.85: The Polynomial Fit Options dialog box.

If the Apparent Fit option is checked, QtiPlot uses the apparent values for fitting, according to the current axis scales. Forexample, select this box to fit exponentially decaying data with a straight line fit when data are plotted on a log scale. When thischeck box is selected and the data has error values associated with it, QtiPlot uses the larger of the positive/negative errors asweight. Apparent Fit is only useful when you fit from a graph and change the plot axis type (from Linear to Log10, for example).If you check this option, QtiPlot will first transform raw data into new data space as specified in the graph axis type, and then fitthe curve with the new data. Otherwise, QtiPlot always fits raw data directly, regardless of the axis type. Apparent fit is equivalentto direct fit if you first transform raw data on the worksheet, and leads to completely different results from direct fit if your graphaxis is non-linear.

The numerical result of the polynomial fit operation will be listed in the Log Panel. If the option Show Formula on Graph? ischecked the result will also be displayed in the output graph window under the form of a new text legend.

5.25 The Fit Wizard

This dialog is activated by selecting the command Fit Wizard... from the Analysis Menu. This command is active if a plot or atable window is selected. In the latter case, this command first creates a new plot window using the list of selected columns inthe table.

This dialog is used to fit discrete data points with a mathematical function. The fitting is done by minimizing the least squaredifference between the data points and the Y values of the function.

Note:

If the data points are modified, the fit is not re-calculated. Then, you need to remove the old fitted curve and to redo the fitwith the same function and the new points.

5.25.1 Select Function Tab

The top of the dialog box is used to select one of 4 Categories of functions: 1) user defined functions which have been previouslysaved, 2) the classical functions provided by QtiPlot in the analysis menu, 3) simple elementary (basic) built-in functions, and 4)external functions provided via plugins.

To choose a function, first select a category and then the desired function from the displayed Function list. Clicking on thecheckbox under the selector will clear the contents of the function entry text pane (see below) and copy the selected function intoit. You can also click the Add expression button to copy the selected function, but this will not clear any previous contents. Ifyou’ve selected one of the "basic" functions, there will be no checkbox and you will need to use the Add expression button.

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The bottom half of the dialog box allows you to define your own function. You can either write you own mathematical expres-sion from scratch or add expressions from the function selector with the Add expression button. Once a custom expression iscompleted, clicking on the Save button will add the function to the list of user defined functions. The Name field will be usedas the name of the function. A copy of the function is saved on disk with the extension ".fit". You can define the folder where".fit" files are saved using either the Choose models folder... button (shown only when "User defined" is selected) or by selectinga new folder in the Save file dialog. Functions can be removed from the User Defined list by selecting them and clicking on theRemove button. You will be asked to confirm the deletion.

This first step is used to define the function which will be used for fitting. When you are ready to perform the fit, click on thebutton to activate the Fitting Session.

Figure 5.86: The first step of the Fit Wizard... dialog box.

5.25.2 Fitting Session Tab

The second step is to define the parameters for the fit. You have to give an initial guess for the fitting parameters.

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This second step is used to define the parameters of the fit.

Figure 5.87: The second step of the Fit Wizard... dialog box.

In this second tab you can also choose a weighting method for your fit (the default is No weighting). The available weightingmethods are:

1. No weight: all weighting coefficients are set to 1 (wi = 1).

2. Instrumental: the values of the associated error bars are used as weighting coefficients wi = 1/eri2, where eri are the error

bar sizes stored in error bar columns. You must add Y-error bars to the analyzed curve before performing the fit.

3. Statistical: the weighting coefficients are calculated as wi = 1/yi, where yi are the y values in the fitted data set.

4. Arbitrary Dataset: allows setting the weighting coefficients using an arbitrary data set wi = 1/ci2, where ci are the values

in the arbitrary data set. The column used for the weighting must have a number of rows equal to the number of points inthe fitted curve.

5. Direct Weighting: allows setting the weighting coefficients using an arbitrary data set wi = ci, where ci are the values inthe arbitrary data set. The column used for the weighting must have a number of rows equal to the number of points in thefitted curve.

After the fit, the log window is opened to show the results of the fitting process.

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5.25.3 Custom Output Tab

Depending on the settings in the Custom Output tab, a function curve (option Uniform X Function) or a new table (if you choosethe option Same X as Fitting Data) will be created for each fit. The new table includes all the X and Y values used to computeand to plot the fitted function and is hidden by default. It can be found in and viewed from the project explorer.

This third step is used to customize the output of a fitting operation.

Figure 5.88: The third step of the Fit Wizard... dialog box.

The controls in the Parameters Output group box can be used in order to define the options for the display of the results from datafit operations. The Format list box allows to choose a default numerical format. The value of the Significant Digits option canbe used to customize the precision of the output and has a different meaning depending on the numeric format. The followingformat and precision options are available:

Default - Decimal or scientific e-notation, whichever is the most concise. The value of the Significant Digits control representsthe maximum number of significant figures in the output (trailing zeroes are omitted).

Decimal: 1000 - Decimal notation. The value of the Significant Digits control represents the number of digits after the decimalpoint.

Scientific: 1E3 - Scientific e-notation where the letter e is used to represent "times ten raised to the power of" and is followedby the value of the exponent. The value of the Significant Digits control represents the number of digits after the decimalpoint.

This dialog tab also provides controls that can be used to evaluate the goodness of fit. The first is the Residuals Plot button whichis used to display the curve of the plot residuals. The Conf. Bands and Pred. Bands buttons can be used to generate confidenceand prediction limits for the current fit, based on the user input confidence value.

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5.25.3.1 Reported errors

By default, reported errors are not automatically scaled by the square root of the reduced chi-squared value. You can choose toenable this option by checking the Scale errors with sqrt(Chiˆ2/doF) box.

5.25.3.2 Goodness-of-Fit Statistics

After the fit, a series of fit statistics are displayed in the log window allowing evaluation of the goodness of fit. These values are:

1. RSS (Residual Sum of Squares):

is the sum of squares of residuals. This statistic measures the total deviation of the response values from the fit to theresponse values. It is also called the Sum of Squares due to Error (SSE). A small RSS indicates a tight fit of the model tothe data.

2. Chiˆ2/doF:

The reduced chi-square is obtained by dividing the residual sum of squares (RSS) by the degrees of freedom (doF), whichis defined as the number of response values minus the number of fitted coefficients estimated from the response values.Although this is the quantity that is minized during the iterative process, it is typically not a good measure for the goodnessof fit. For example, if the y data is multiplied by a scaling factor, the reduced chi-square will be scaled as well.

3. R-square:

is defined as 1 - RSS/SST, where SST is the total sum of squares. This statistic measures how successful the fit is inexplaining the variation of the data. Put another way, R-square is the square of the correlation between the response valuesand the predicted response values. It is also called the square of the multiple correlation coefficient and the coefficient ofmultiple determination.

R-square can take on any value between 0 and 1, with a value closer to 1 indicating that a greater proportion of varianceis accounted for by the model. For example, an R-square value of 0.8234 means that the fit explains 82.34% of the totalvariation in the data about the average.

If you increase the number of fitted coefficients in your model, R-square will increase although the fit may not improvein a practical sense. To avoid this situation, you should use the degrees of freedom adjusted R-square statistic describedbelow.

Note that it is possible to get a negative R-square for equations that do not contain a constant term. Because R-square isdefined as the proportion of variance explained by the fit, if the fit is actually worse than just fitting a horizontal line thenR-square is negative. In this case, R-square cannot be interpreted as the square of a correlation. Such situations indicatethat a constant term should be added to the model.

4. Adjusted R-square:

The adjusted R-square statistic is generally the best indicator of the fit quality when you compare two models that arenested - that is, a series of models each of which adds additional coefficients to the previous model. The adjusted R-squarestatistic can take on any value less than or equal to 1, with a value closer to 1 indicating a better fit. Negative values canoccur when the model contains terms that do not help to predict the response.

5. RMSE (Root Mean Squared Error):

This statistic is also known as the fit standard error and the standard error of the regression. It is an estimate of the standarddeviation of the random component in the data and is defined as the square root of RSS divided by the degrees of freedom.Just as with RSS, an RMSE value closer to 0 indicates a fit that is more useful for prediction.

The detailed explanations about the meaning of this statistical values were taken from:

http://web.maths.unsw.edu.au/~adelle/Garvan/Assays/GoodnessOfFit.html

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5.26 General Plot Options

5.26.1 Scale Tab

The first tab is used to set the general scales used for two or three axis plots.

Figure 5.89: General plot options dialog: The Scale Tab.

In this tab, you can set the number of ticks used for each axis. This can be done in two ways: 1) Set the number of labels to usefor the entire scale. Whatever number you enter, QtiPlot may adjust the value so as to produce a prettier plot (for example, ifyou enter 7 ticks for a 0..100 scale, QtiPlot will use 10 major ticks spaced evenly from 10 to 100). 2) Set the Step Increment andQtiPlot will generate as many ticks as needed to fill the scale range using the indicated increment. This produces tick spacingsand labels which are more like those that are typically done on hand drawn graphs.

Please note that the number of major ticks cannot exceed the Max Number value defined in the 2D Plots -> Ticks tab of thePreferences dialog. In case you need to display more tick labels (or equivalently use a smaller step size) than allowed by thisdefault limit, you must modify it first.

5.26.2 Grid Tab

The grid tab is used to draw grid lines on the plot. The frequency of the lines are related to the number of labels and major ticksset with the Scale tab.

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Figure 5.90: General plot options dialog: The Grid Tab.

5.26.3 Axis Tab

The third tab is used to modify the setting of the different axes. You must select the axis to be customized in the right window.The label of that axis can then be modified in the title window - see the text options dialog section for more details.

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Figure 5.91: General plot options dialog: The Axis Tab.

5.26.4 Special Ticks Tab

The Special Ticks tab is used to customize the major tick labels for the different axes. You must select the axis to be customizedfrom the list on the right side of the dialog window. The positions of the ticks are displayed in the first column of the table. Thesepositions cannot be modified, editing being disabled for all cells in this column.

It is possible to customize the default labels displayed in the second column of the table as <auto>. In order to finish editing atick label you need to press the Return or Enter keys or the Apply button. Editing is also considered finished and the modificationsare applied when you change the active cell of the table, either with the mouse or by pressing the Tab key. Empty tick labels arenot accepted and are automatically replaced with the default value.

You can define custom colors for each tick label by pressing the corresponding push button in the third column of the table. Thiswill pop-up a color selection dialog.

The tick labels can be shown or hidden by checking or unchecking the corresponding box from the last column. Hidden ticklabels cannot be edited. The visibility of the first and last axis tick labels can also be controlled via the Hide Ticks list box inthe Axis tab. If these labels were already hidden by the user - this option was set to At Axis Begin, At Axis End or At Axis Begin& End - the check boxes corresponding to these labels in the ticks table are disabled and the text Automatic is displayed next tothem.

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Figure 5.92: General plot options dialog: The Special Ticks Tab.

5.26.5 General Tab

The General settings tab is used to customize global aspects of the plot. The canvas is the area bounded by the axes. It is possibleto draw a frame around the canvas and define its color and thickness using the controls in the Canvas frame box.

The controls in the Axes group box allow to modify the lengths of the major and minor ticks for all layer axes. You can alsodefine a maximum number of major ticks using the Max Number spin box. The value of this parameter becomes the maximumlimit for the Major Ticks value in the Scale tab of this dialog

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Figure 5.93: General plot options dialog: General Settings.

5.27 The Plot Wizard

This dialog is activated by selecting the command Plot Wizard from the Plot Menu or with the Ctrl-Alt-W key. This command isalways active.

This dialog is used to build a new plot by selecting the columns from the tables available in the current project. First, select thetable you want to use from the Worksheet combo box and click on New curve to create the curve. After that, select at least onecolumn for X and one for Y using the <->X and <->Y buttons. You can also select columns for Z, X-errors and/or Y-errors usingthe buttons provided for these options. The plot will be created using the default style defined using the ’2D Plots -> Curves’ tabin the Preferences dialog.

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In this example, one curve is selected from the first table, and the other from the second table (with X error bars)

Figure 5.94: The plot wizard dialog box.

5.28 Project Explorer Find Dialog

The project explorer find dialog is activated using a right-click on a folder item in the project explorer and selecting Find... orselecting the command Find... from the Windows Menu. It permits searching a window anywhere in the project. It is possible toperform a search in windows or table columns metadata (name, label and comments) or in other specific elements like data cells,text objects on graphs or content of note windows.

Figure 5.95: The project explorer find dialog.

When the Find button is pressed and the search is proceeding, the button becomes Cancel. If the Cancel button is pressed whileperforming a search, the undergoing operation stops, the button becomes Find again and the partial search result is output in thebottom table of this dialog.

If the Case Sensitive box is checked, the search will distinguish between uppercase and lowercase characters when searching thestring typed in the Find... box. When the Whole Word option is selected, the search only looks for words that match completely

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with the content specified in the Find... box. The Allow Wildcards parameter specifies whether or not the wildcards ? and * areused in the Find... edit box: ? matches any single character and * matches zero or more of any characters. Please note that theWhole Word and Allow Wildcards options cannot be checked simultaneously.

When the mouse is hovered over a row of the result table an information tooltip is displayed. If the row is double-clicked thecorresponding folder/window becomes active and the window is maximized.

5.29 Preferences Dialog

The preference dialog is used to customize the default behavior of QtiPlot. There are six pages of options which are selectedusing one of icons from the column on the left hand side of the dialog. The text box at the top of the dialog shows the name ofthe selected page. No matter which page is selected, there are always seven buttons along the bottom edge of the dialog: Help,Default Options, Save As, Load Settings, Apply, OK and Cancel.

Changes must be confirmed using either the Apply or OK buttons. The OK button additionally closes the dialog. Upon confir-mation, changes are saved and stored immediately. The Cancel button will not undo changes which have already been confirmedbut provides a means of exiting the dialog without confirming any changes that are pending. The Default Options button willreset the values of all the settings to the program defaults.

The Help button opens the quick help window corresponding to the selected page.

Finally, the Save As... button opens a file save dialog allowing to export the user settings to a .ini or .txt file. Starting with version0.9.9.6 user settings are saved to a file called QtiPlot.ini that is stored into a hidden subfolder called .qtiplot in the user’s homedirectory. Therefore you can customise QtiPlot on any computer, export the settings file and load it on another computer bypressing the Load Settings button or copy it manually to the .qtiplot subfolder of your home directory in order to get the samebehaviour of QtiPlot.

5.29.1 General Preferences

Selecting the General icon displays the General options page. The controls that control the general options are grouped ontoa set of 6 tabs. Each tab references a set of related options.

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5.29.1.1 Application Tab

Figure 5.96: The preferences dialog: general parameters for the application.

Controls on the Application tab are used to set application wide defaults.

The Language combo-box lists the translations available in QtiPlot. Select a language from this list. Control names, programlabels, etc., will be displayed in this language.

The Style combo-box defines the style used by QtiPlot for the window decorations. These include stylistic aspects of buttons,dialog boxes, window borders and titles, etc. Available styles are those currently available in the Qt library.

The Font chooser selects the font used in the GUI (menus, dialogs, etc). It doesn’t apply to plots.

The Default Scripting Language combo-box is used to set the scripting language. muParser is the default. Python will also beavailable if Python support has been compiled into QtiPlot.

The Undo Stack Size is the number of operations that can be undone/redone. By default it is set to ten operations. A high valuefor this parameter can be very costly in terms of memory consumption, especially for large matrices.

The Endline character combo-box defines the end of line convention used by QtiPlot for copy/paste operations and for exportingmatrices/tables to ASCII files. The end of line convention can be set to any one of the following: Line Feed (LF), CarriageReturn + Line Feed (CRLF) or Carriage Return (CR) only.

The Start New Project combo-box is used to select what type of child window, if any, is created when a new project is started.The default is for new projects to contain an empty Table window.

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The Import Excel files using option allows to specify the method used by QtiPlot when trying to import Excel files. Dependingon the operating system QtiPlot provides four methods. The first one (the ExcelFormat library) can fail for certain files, thereforeQtiPlot provides a second solution which needs LibreOffice installed on your computer. The third solution which uses OpenOfficeis obsolete and users that employed it in older versions of QtiPlot are strongly encouraged to install LibreOffice since it is muchfaster (the path to the soffice executable must be correctly set in the File Locations tab). Finally, on Windows platforms, if youchoose the option Locally installed Excel, QtiPlot uses Microsoft Excel as a server application in order to import the data sheetsand also the plots.

The Clipboard Image Format option allows to specify the method used by QtiPlot when copying plot images to clipboard.When the first method (Bitmap) is chosen QtiPlot stores the plots as raster images, while the other methods use vectorial imageformats: Enhanced Metafile (.emf), the default format on Windows platforms, Encapsulated Postscript (.eps), the default onLinux platforms and Scalable Vector Graphics (.svg).

The Save Every check box is used to turn the auto-save feature on(checked) or off(unchecked). The associated textbox/spinbutton is used to set the autosave interval. The interval is in minutes. The textbox only accepts positive integer numeric input.All other input is ignored.

The Backup project before saving option is used to create a backup copy of the current project before saving a changed projectfile. This option is enabled when checked.

When checked, the Check for new versions at startup option will look for program updates on the internet each time the programis started. The default is disabled.

When checked, the Enable Autocompletion option enables the autocompletion feature of QtiPlot. Autocompletion is enabled bydefault in all QtiPlot editors (Notes, Script Windows, and values dialogs for matrices and tables). Completion suggestions areautomatically popped-up for words that have more than two characters, but you can trigger autocompletion at any time using theshortcut Ctrl+U. Autocompletion can be disabled by unchecking the Enable autocompletion option.

When checked, the Open last project at startup option enables the feature that reloads the last active project when QtiPlot isrestarted. The default is enabled.

5.29.1.2 Confirmations Tab

The General Preferences: Confirmations tab contains a set of 8 check boxes that enable/disable various warning prompts. Thefirst six are warnings given when deleting project windows (Folders, Tables, Matrices, 2D Plots, 3D Plots, and Notes). Theremaining 2 are warnings given when 1) renaming or appending windows with names that are already used in the current project,and, 2) when attempting to overwrite an existing file. All warnings are enabled by default.

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Figure 5.97: The Preferences dialog: Confirmations tab.

5.29.1.3 Colors Tab

In this tab, you can change the default color for the QtiPlot workspace, the panel background color and the panel text color.Panels refer specifically to the Log Window and the Project explorer.

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Figure 5.98: The Preferences dialog: Colors tab.

5.29.1.4 Numeric Format Tab

The Numeric Format tab allows customizing several aspects of numeric formatting used by QtiPlot. The Number of Decimal Dig-its specifies the default precision used for any calculations applied to your data in Tables and Matrices. The Decimal Separatorsfields allow selection of the characters used as the decimal point and the thousands separator. By default, QtiPlot uses the localesettings detected on your system. Separate fields are provided for data in tables/matrices and data copied to the clipboard. Thethousands separator can be eliminated completely from tables and matrices by checking the Omit Thousands Separator option.QtiPlot will convert all the existing data in your project to the new settings when you click the Apply button.

If the option muParser uses C locale settings is checked operations like setting column/matrix values or plotting function curvesrequire that all the data input parameters are written using the standard convention for the C programming language: the decimalpoint is the dot character and the thousands separator is omited. Uncheck this option in order to use the numeric format settingsspecified above.

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Figure 5.99: The Preferences dialog: Numeric Format tab.

5.29.1.5 File Locations Tab

The File Locations tab allows you to define custom locations for the folders containing the translation files, the manual filesand the Python configuration files (qtiplotrc.py and qtiUtil.py) if QtiPlot was built with Python scripting support. Default folderentries are also provided for scripts that are to be loaded at program startup.

The LaTeX Compiler and LaTeX Preamble fields are useful if you want to add TeX formated equations to 2D plots and you preferto generate them using a compiler installed on your computer. The LaTeX Preamble field is optional, you may leave it blank.

In the LaTeX Compiler field you must provide the path to the LaTeX executable. On Linux this path is set by default to /usr/bin/latex. On Windows operating systems you need to choose the location of the latex.exe file. A very popular LaTeXcompiler for Windows is MiKTeX. On macOS you can use the LaTeX distribution provided by the MacPorts project. In this casethe path to the LaTeX executable is probably /opt/local/bin/latex.

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Figure 5.100: The preferences dialog: File Locations Tab.

5.29.1.6 Keyboard Tab

The Keyboard tab makes possible to define custom shortcuts for all actions in the menus and toolbars of QtiPlot.

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Figure 5.101: The preferences dialog: Keyboard Tab.

5.29.1.7 Internet Connections Tab

Settings on the Internet Connection tab are only needed if you connect to the internet via a proxy server. If you don’t now howto set these options, contact your Network Administrator or other suitably knowledgeable person.

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Figure 5.102: The preferences dialog: Internet Connection Tab.

5.29.2 Tables Preferences

Selecting the Tables icon opens the second page of the preferences dialog which allows customizing default aspects of tables:background, text colors, and fonts for tables and labels.

The Alignment selection box can be used to define the default position of the text in the table cells: the text can be aligned withthe left or right edge of the columns or centered horizontally in the available space.

If the Automatically Recalculate Column Values option is checked, all modifications in the values of a column trigger a recalcu-lation of all columns with formulas depending on the modified column.

The controls in the Display group box can be used to select what information is visible in the the table header below the columnnames. Available options are the Long Names, the Units and the column Comments.

The Preview group box can be used to define the size of the picture that is displayed for each table column after a right click onthe colum header. Unchecking this group box disables the display of the preview picture.

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Figure 5.103: The Preferences dialog: table options.

5.29.3 2D Plot Preferences

Selecting the 2D Plots Icon opens the third page of the preferences dialog. This set of options is used to customize defaultaspects of 2D plots.

5.29.3.1 Options Tab

The Options tab may be used to customize the general behavior of the plot layers. Most of the changes made to these optionswill be applied only to newly created plots. Changing a few of these options, such as plot axis Autoscaling, scaling of fonts andthe behavior on resize events will affect existant plots.

The controls in the Data Drawing Options group box can be used in order to set the default drawing options that can be modifiedlater on for each plot layer via the Layer Display tab of the Plot Details dialog.

If the Margins box is checked QtiPlot automatically adds some amount of space before and after the data values along each axisscale. The effect of this option is mainly visible when creating new plots from table columns or when rescaling a plot layer sothat all data on the graph is visible, using the Graph -> Rescale To Show All command.

The names of the other options in this group box should be self explaining.

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Figure 5.104: The preferences dialog: 2D plot options.

5.29.3.2 Curves Tab

The Curves tab contains a large number of controls that define the default style used when creating a new plot. The operation ofthese controls should be self evident.

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Figure 5.105: The Preferences dialog: Curves Tab.

5.29.3.3 Error Bars Tab

The Error Bars tab contains the controls that define the default style used when adding error bars to a 2D plot curve.

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Figure 5.106: The Preferences dialog: Error Bars Tab.

5.29.3.4 Axes Tab

The first panel in this tab allows to specify the dominant stylistic aspects of the plot axes like their Thickness, the visibility of thebackbone line (with the help of the Draw backbones check box) and the space between the axes and their title and between themajor ticks and their corresponding labels.

If you want that the axes intersect in the center of the plot layer you should check the Crossing axes layout box. With the help ofthe controls from this panel it is possible to precisely define the positions of the Horizontal and Vertical axes either in percentagesof the plot canvas dimensions (width and height) or by specifying a custom scale value.

Using the controls in the Arrow group box it is possible to define a default end arrow shape for the Horizontal and Vertical axesonly. The Left, Right, Bottom and Top axes cannot display arrows at their end point.

The Enabled axes panel controls which axes and more precisely which axes elements will be visible in a new plot layer. Withthe use of the Show check box it is possible to enable/disable a plot axis. The display of the major tick labels is controlled withthe Labels check box. If you want to disable the display of an axis title you simply remove the text in the Title edit box.

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Figure 5.107: The Preferences dialog: Axes Tab.

5.29.3.5 Ticks Tab

The Ticks tab defines the default style for axis ticks drawn on newly created plots. The option Max Number can be used in orderto set a limit for the number of major ticks that are displayed on each axis if the plot layer is rescaled automatically, for exampleafter using the Rescale To Show All command.

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Figure 5.108: The Preferences dialog: Ticks Tab.

5.29.3.6 Grid Tab

The Grid tab defines the default aspect of plot layer grids.

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Figure 5.109: The Preferences dialog: Grid Tab.

5.29.3.7 Geometry Tab

The Geometry tab defines the default size for the drawing area of a plot layer and the margins around the layers. When the Keepaspect ratio option is checked, changing either the width or height will proportionally change the other dimension. Also, theaspect of the plot canvas (ratio between width and height) will remain unchanged for all future plot layers when you manuallyresize a graph window.

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Figure 5.110: The Preferences dialog: Geometry Tab.

5.29.3.8 Speed Tab

The Speed tab lets the user enable/disable antialiasing when drawing/redrawing 2D plots. Antialiasing is a major source of slow-down when rendering 2D plots. Unchecking the Antialiasing checkbox disables antialiasing for all curves, which probably willonly be needed in extreme circumstances. Checking the Disable for curves with more than checkbox will disable antialiasingonly for curves having data sets larger than the threshold set with the textbox to the right of the Disable for curves with morethan checkbox. Disabling this option is probably not a good idea. The default is for both of these options to be enabled, with athreshold of 1000 data points. Proper setting of these options is essential to keeping the application responsive.

The option Disable mouse tracking for curves with more than ... data points can be used to stop detecting the position of themouse pointer for curves with a very large number of data points. Data tools like the Data Reader command or the SelectData Range command will no longer work for the curves with more data points than the value defined for this option, but theapplication will be more responsive.

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Figure 5.111: The Preferences dialog: Speed Tab.

5.29.3.9 Fonts Tab

The Fonts tab defines the default fonts used when creating new plots. Options are provided for the plot Title, plot Legend, AxesLabels, and Axes Numbers.

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Figure 5.112: The Preferences dialog: Fonts Tab.

5.29.3.10 Print Tab

The Print tab allows you to control a few default options that are used when printing 2D plots. If you want layers to be printedwith their original dimensions, you must be sure to uncheck the Scale layers to paper size option. Checking the Print Cropmarksoption ensures that some visible marks will be drawn around the borders of the plot.

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Figure 5.113: The Preferences dialog: Print Tab.

5.29.4 3D Plot Preferences

Selecting the 3D Plots Icon opens the fourth page of the preferences dialog. This set of options is used to customize defaultaspects of three dimensional plots. Most of the options are self-explanatory. However, the Resolution option needs clarification.This option is more or less akin to a speed drawing mode, which can be very useful when working with large data sets. Largervalues of the Resolution option result in fewer data points being drawn on 3D plots, and therefore a higher drawing speed. WhenResolution is set to 1, all data points are drawn.

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Figure 5.114: The preferences dialog: 3D plot options.

5.29.5 Notes Preferences

Selecting the Notes Icon opens the fifth page of the preferences dialog. This set of options is used to customize some of thedefault characteristics of the text editors, such as the length of the TAB character and the font. The user can also specify whetheror not line numbers should be displayed. Displaying the line numbers can be particularly helpful when debugging Python scripts.

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Figure 5.115: The preferences dialog: note options.

5.29.6 Fitting Preferences

Selecting the Fitting Icon opens the sixth page of the preferences dialog. This page is used to set default fitting options. Mostof the options are standard and straightforward.

The Generated Fit Curve options may be confusing at first glance. While it may be typical to plot a fit curve as y=f(x) usingthe original X data that was used in the fitting operation, QtiPlot provides the alternative (by selecting the Uniform X Functionoption) of plotting the curve using a user specified number of X data points (default=100) uniformly spaced over the X range ofthe fit. Since linear fits are completely defined by 2 points, you can also have QtiPlot default to simply plotting linear fits using 2data points by checking the 2 points for linear fits option.

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Figure 5.116: The preferences dialog: fitting options.

The controls in the Parameters Output group box can be used in order to define the default options for the display of the resultsfrom data fit operations. The Format list box allows to choose a default numerical format. The value of the Significant Digitsoption can be used to customize the precision of the output and has a different meaning depending on the numeric format. Thefollowing format and precision options are available:

Default - Decimal or scientific e-notation, whichever is the most concise. The value of the Significant Digits control representsthe maximum number of significant figures in the output (trailing zeroes are omitted).

Decimal: 1000 - Decimal notation. The value of the Significant Digits control represents the number of digits after the decimalpoint.

Scientific: 1E3 - Scientific e-notation where the letter e is used to represent "times ten raised to the power of" and is followedby the value of the exponent. The value of the Significant Digits control represents the number of digits after the decimalpoint.

For all data analysis operations, not only fitting, there is a mechanism introduced in release 0.9.9.11 of QtiPlot that allowsto trigger a recalculation when the data source is modified. It is possible to specify the desired recalculation mode using theRecalculate list box. The available options are:

No - No recalculation when data changes.

Auto - A recalculation is automatically performed when input data changes. This is the default option.

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Manual - No recalculation is triggered when data changes, instead the user can perform a recalculation at any time by pressingthe Recalculate button from the Analysis tab of the plot details dialog.

Please note that if the recalculation mode is set to No the fit object is deleted from memory when the operation ends. In theother two cases the fit object is attached to the result plot curve and stored into the memory of the output graph window. Therecalculation mode can be changed later on via the Analysis tab of the plot details dialog.

If the Apparent Fit option is checked, QtiPlot uses the apparent values for fitting, according to the current axis scales. Forexample, select this box to fit exponentially decaying data with a straight line fit when data are plotted on a log scale. When thischeck box is selected and the data has error values associated with it, QtiPlot uses the larger of the positive/negative errors asweight. Apparent Fit is only useful when you fit from a graph and change the plot axis type (from Linear to Log10, for example).If you check this option, QtiPlot will first transform raw data into new data space as specified in the graph axis type, and then fitthe curve with the new data. Otherwise, QtiPlot always fits raw data directly, regardless of the axis type. Apparent fit is equivalentto direct fit if you first transform raw data on the worksheet, and leads to completely different results from direct fit if your graphaxis is non-linear.

5.30 Printer-setup

This dialog box is opened by the Print command from the File menu or by entering the Ctrl-P key. It is used to print the selectedwindow (plot or table) and its exact appearance will depend both upon your operating system and the printers that you haveavailable. The following screenshot shows the dialog on a Linux system with one printer that uses the KDE window manager.

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Figure 5.117: The Print dialog.

5.31 Set Column Values

This dialog is activated with the Set Column Values... command from the Table menu or by entering the shortcut Alt-Q. Itprovides for filling a column with the result of a function evaluation.

The available mathematical functions can be viewed with the help of the function selector button which displays the capital greekletter sigma Σ. By pressing this button a dropdown menu of intrinsic functions grouped by the first letter of their name willbe shown. Selecting a function name will copy it into the function definition pane. Details of these functions and supportedmathematical operators are listed in the muParser section in the chapter on Mathematical Expressions and Scripting. Also atool tip for function syntax is displayed by double-clicking an inserted function name while keeping the left button of the mousepressed.

The special function, col(c), is used to access the values of column c, where c is the column’s number (as in col(2)) or its namein double quotes (as in col("time")). You can also obtain values from other tables using the tablecol(t,c) function, where t is thetable’s name in double quotes and c is the column’s number or its name in double quotes (example: tablecol("Table1","time")).

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The variables i and j can be used to access the current row and column numbers. Similarly, sr and er represent the selectedstarting and ending row, respectively.

Using Python as scripting language gives you even more possibilities. Not only can you use arbitrary Python code in the functionbody, but also access other objects within your project. For details, see the section on Pythonin the chapter on MathematicalExpressions and Scripting. Nevertheless, even though Python allows for a more powerful syntax, it can be quite slow for verylarge tables. Therefore you might want to use muParser instead, even when Python is set as the default script engine for yourcurrent project. Checking the Use built-in muParser option will force the use of muParser as the scripting engine. This greatlyincreases the speed of the evaluation for single line expressions.

Figure 5.118: The Set Column Values... dialog.

Warning: When you make changes to the values in a table which contains "filled" values, the dependent values are not recomputedunless the Automatically Recalculate Column Values option is checked in the Tables tab of the Preferences dialog. If this optionis unchecked, you will have to explicitly tell QtiPlot to recalculate individual cells or whole columns or rows by selecting"Recalculate" from their context menu or by pressing Ctrl-Return.

5.32 Extract Data

This dialog is activated with the Extract Data... command from the Table menu. It opens a dialog which allows you to definea set of conditions that are used to filter the data in the currently active table. When a condition has been defined, Applying thecondition will create a new table into which all rows that meet the condition will be copied. The original table is unchanged. Forexample, the condition col("1") > 0.5 will generate a new table that contains all the rows from the active table which have a valuegreater than 0.5 in column 1.

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Figure 5.119: The Extract Data... dialog.

The available mathematical functions can be viewed with the help of the function selector button which displays the capital greekletter sigma Σ. By pressing this button a dropdown menu of intrinsic functions grouped by the first letter of their name willbe shown. Selecting a function name will copy it into the function definition pane. Details of these functions and supportedmathematical operators are listed in the muParser section in the chapter on Mathematical Expressions and Scripting. muParseris the only scripting language that can be used in this dialog.

The special function, col(c), is used to access the values of column c, where c is the column’s number (as in col(2)) or its namein double quotes (as in col("time")). You can also obtain values from other tables using the tablecol(t,c) function, where t is thetable’s name in double quotes and c is the column’s number or its name in double quotes (example: tablecol("Table1","time")).

The variables i and j can be used to access the current row and column numbers. Similarly, sr and er represent the selectedstarting and ending row, respectively.

The filtering condition is built with the common operators +, -, *, /, %, and ˆ (for addition, subtraction, multiplication, division,modulus operator and exponentiation, respectively) and the logical operators: >, >=, <, <=, !=, ==. These operators can be addedby pressing the + button and choosing the operator needed from the dropdown menu.

5.33 Set Matrix Dimensions

This command appears in the Matrix menu. It allows direct specification of the number of rows and columns of a matrix. In thiswindow, you can also define a range for X-values and Y-values. These X and Y ranges will be used in new plots as the initialscale ranges. They are also available via the x and y variables if you choose to define the contents of the matrix with the SetValues Dialog.

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Figure 5.120: The Set Dimensions... dialog for matrix.

You can also define a Long Name, Units and Comments for X / Y / Z coordinates under the X Labels, Y Labels or Z Labels tab.These labels can be used as X / Y /Z axis labels in 3D graphs.

5.34 Matrix Properties

This command is located in the Matrix menu. It allows setting some global properties of the selected matrix, such as the cellwidth (in pixels) and the format used for numbers.

Figure 5.121: The Set Properties... dialog for matrices.

5.35 Set Matrix Values

This command is located in the Matrix menu. It allows filling in a matrix with the results of evaluating a function, z=f(i,j), inwhich i and j are the row and column numbers.

You can use the X-values and Y-values defined with the Set Dimensions... command, and also define your functions based on thex and y variables.

Functions can span several lines. The available intrinsic functions are listed in the muParser section of the Mathematical Expres-sions and Scripting chapter.

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Figure 5.122: The Set Values... dialog for matrix.

Using Python as scripting engine for the calculation of matrix values has the advantage of a more powerful syntax. The drawbackis that it can be quite slow for large matrices. You can use muParser instead, even if Python is set as the default script engine foryour QtiPlot project, by checking the Use built-in muParser box. Note that muParser is very fast for the evaluation of single lineexpressions only, therefore try to avoid syntax like:

a = cell(1, 1)b = cell(2, 2)a*b*x + b*x*x + a

in preference for something like the following:

cell(1, 1)*cell(2, 2)*x + cell(2, 2)*x*x + cell(1, 1)

which will greatly increase the speed of evaluation!

5.36 Bin Matrix Dialog

Figure 5.123: The Bin Matrix Dialog dialog box.

This dialog is opened when you select the Convert to Matrix -> 2D Binning... command from the Convert to Matrix menu. Itallows to customize the process of generating a new matrix by counting the number the data points falling within a given XYrange and storing the bin counts as Z values in this new matrix.

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The initial coordinates of the output matrix are automatically calculated from the input data range, but of course you can cus-tomize them via the input boxes from the Matrix Coordinates group box. The Columns and Rows input boxes in the MatrixDimensions group allow to specify the number of bins in the X and respectively Y range.

In order to understand how the frequency count process works please consider the following example: the table to be convertedhas two columns (X and Y) both containing random values between 0 and 1. We decide to create a new matrix with 10 rows and10 columns, that is 100 bins. If we represent the input data using a scatter plot we get the graph bellow, where the scale divisionswere changed to have a 0.1 step for both axes. In this graph, each square of the plot grid represents a 2D bin. QtiPlot counts thenumber of scatter points in each square and stores these values in the new matrix.

Figure 5.124: Scatter plot showing the number the data points falling within each 2D bin.

5.37 Random XYZ Gridding Dialog

This dialog is opened when you select the Convert to Matrix -> Random XYZ... command from the Convert to Matrix menu. Itallows to customize the process of generating a new matrix from a collection of randomly distributed XYZ data samples, usingShepard’s method.

This interpolation method, also called the Inverse distance weighting method, is often used to derive estimates of the surfaceheight at the vertices of a regular grid from irregularly spaced samples. Consider N data samples, that is, we have N triples (xi,yi, zi). We want to estimate the height z given a position on the plane (x, y). The general form for estimating z is given by thefollowing formula, where p determines the relative importance of distant samples (see the article Nearest neighbour weightedinterpolation by Paul Bourke for more explanations):

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Figure 5.125: The Shepard’s interpolation method.

The Search Radius input box in the dialog corresponds to the parameter p from the formula above. The initial dimensions ofthe output matrix are automatically set by QtiPlot to be the double of the number of sample data points, but of course you cancustomize them via the Columns and Rows input boxes from the Matrix Dimensions group box. The same remark applies to thecontrols in the Matrix Coordinates group box.

By checking/unchecking the Preview box it is possible to enable/disable the display of the input samples and of the interpolated3D surface. The color map used to draw the input data points as well as the color of the surface line mesh and its smoothenesscan be customized via the 3D Plots tab from the Preferences dialog.

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Figure 5.126: The Random XYZ Gridding dialog box.

5.38 Surface plot options

This dialog box is used to customize 3D function plots created using the New 3D Surface Plot... command from the File menu.It is activated by a double click on a 3D plot.

5.38.1 Scale Tab

The first tab is used to modify the X, Y, and Z ranges. It also allows specification of the number of labels (major ticks) to bedrawn on the axes, as well as the number of minor ticks.

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Figure 5.127: The surface plot options dialog box.

5.38.2 Axis Tab

The second tab defines the main parameters of the three axes: the axis label, its font, and the length of the ticks. Tick length isdefined in the same units as the axis range. If the graph scales are changed, QtiPlot will re-calculate the length of the ticks. Thefont button on this tab only allows modification of the font used for the label. The font used for axis numbers is selected using thefont control on the General Tab. The superscript and subscript buttons allow for easy insertion of LaTeX superscript/subscriptcommands. The superscript/subscript texts will only be rendered as such if you export the plot to a ".tex" file by choosing theLaTeX file text mode in the advanced settings of the export dialog. In order to render the superscripts/subscripts, the exportedLaTex file must be compiled separately, therefore you need a LaTeX environment installed on your computer.

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5.38.3 Grid Tab

The third tab is used to define or modify the properties of the plot grid.

5.38.4 Title Tab

The fourth tab is used to define or modify the title of the plot. You can add LaTex format subscripts, superscripts, bold characters,etc in your title in a manner identical to that described for LaTex formatting in the Axis Tab.

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5.38.5 Data Tab

The fifth tab allows modification of the properties of the 3D curve/surface.

5.38.6 Colors Tab

The sixth tab allows modification of the colors used for the 3D surface.

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The Linear color map group defines the color scheme which is used to show Z-values. If the Scale Colors box is checked, a Zvalue will be represented by a color defined as a linear interpolation between the adjacent values in the color table.

You may also read a colormap from a file. The format of the file is simple: each line defines a color by red, green and blue valuesas integers between 0 and 255. Numbers should be separated by spaces. You can find several examples of colormaps on theQtiPlot web site.

5.38.7 3D Vectors Tab

The 3D Vectors tab is used to enable/disable the display of 3D vectors and to customize their appearance.

Figure 5.128: The 3D Vector options tab.

5.38.8 Legend Tab

The Legend tab is used to enable/disable the display of the plot legend and its appearance.

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Figure 5.129: The legend tab.

5.38.9 General Tab

The General tab is used to define some global parameters and the aspect ratio of the plot. The default behavior is to use perspectiveto compute the 3D plot. If you choose to check the Orthogonal check box, the plot will use a vertical Z axis regardless of theview angle of the plot.

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Figure 5.130: The general plot options tab.

5.38.10 Print Tab

The Print tab is used to define some useful print options, like scaling to the printer’s paper size or showing cropmarks.

Figure 5.131: The 3D plot print options.

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5.39 Sorting Options

This dialog is activated by selecting the Analysis -> Sort Table command. It operates on all columns of the active table. Youhave the option to sort the columns:

• separately: each column will be sorted independently in ascending or descending order

• together: the column selected as the leading column will be sorted into ascending or descending order. The other columns willbe sorted so as to keep the rows unchanged.

Figure 5.132: The Sorting Options Dialog.

5.40 Tex Equation Editor

This dialog is activated by selecting the Add Equation... command from the Graph menu.

Figure 5.133: The Tex Equation Editor.

It can be used in order to add a Tex formatted equation to the plot layer. The equation is rendered under the form of a bitmapimage created by a third party tool. Two image generation methods are available: a web service (which requires a workinginternet connection) or a locally installed LaTeX compiler, the latter method being strongly recommended since it provides moreflexibility.

The web service used by QtiPlot up to release 0.9.9.10 was provided by MathTran (http://mathtran.org/). Since the beggining ofMay 2017 this web service seems to have been discontinued, therefore starting with release 0.9.9.11 QtiPlot uses the services of

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another website: CodeCogs. This server brings the possibility to set a transparent background for the equation by checking theTransparent box.

If you have installed a LaTeX compiler on your computer you don’t need to enter document/equation environment commandssince QtiPlot automatically does it for you: it creates a temporary file which contains either the following hardcoded preamble:

\documentclass{article}\pagestyle{empty}

or a custom preamble that is read from a user defined file path (since one might want to use particular LaTeX packages).

The following code is then appended to the temporary .tex file:

\begin{document}\huge{\\mbox{$text in the editor window$}}\end{document}

The paths for both the LaTeX compiler and the custom preamble file can be set via the File Locations tab of the Preferencesdialog.

The generation method using a local compiler allows for compilation of complete LaTeX documents and not just of equationmarkup, so that you can fully customize the image output in terms of font size, text color and background color. Using thismethod you can also force a transparent background for the equation by checking the Transparent box.

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Figure 5.134: The Tex Equation Editor: compilation of complete LaTeX documents.

5.41 Text options

This dialog can be opened using several different commands, such as the Title... command, or simply by double clicking on anaxis title in your plot. The Color, Font and Alignment commands allow the modification of the general settings of the text label.You can also specify the distance between the label and the corresponding axis, using the Distance to axis box.

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Figure 5.135: The axis title options dialog.

It is worth knowing that all HTML tags and ASCII codes are understood by QtiPlot, therefore you can use them in order todisplay special symbols or get fancy color effects, like in the examples bellow. Please note that the font HTML tag also acceptscolors in the #RRGGBB notation:

<font color = #ff7300>&#9728;</font> Sunshine<font color=red>red</font><font color=#00ff00>green</font><font color=blue>blue</font><span style=’font-family:Symbol’>t</span>_sat

Clicking on the button opens a dialog allowing to add a HTML font tag by selecting the desired custom RGB color from acolor grid.

The following slightly modified dialog is opened when you double click on texts/legends in your plot in order to customize them.It also allows adding text boxes to a plot layer. When the text object is a legend (a listing of the curves plotted on the layer) thecurve symbols and lines are also drawn in the text box, in front of the curve names. In order to display the symbol of a curve andthe name of the data set, the following syntax is used: \l(1.2)%(1.2). In this example the first integer before the dot is the indexof the plot layer and the second value, the number 2, refers to the index of the curve. The index of the layer is optional, if notspecified, the parent layer is used.

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Figure 5.136: The legend/text options dialog.

The % character is an alias for the name of the data set. By adding ",@C" or ",@L" to the number you can alternatively usethe name or comment of the dataset, e.g. \l(2)%(2,@C) will use the column name. Additionally, you can use "@W" to displaythe table name and "@WL" for the table label. To display the contents of a specific cell of the source data table use %(curve#,@L,col,row). If the col parameter is missing the y-column of the dataset is used.

In order to define custom colors for different text strings, like the names of the datasets for example, it is possible to use the \cn()escape sequence, where n is the index of the colors in the Indexed Colors list defined in the Curves tab of the Preferences dialog.

\l(1)\c1(%(1))\l(2)\c2(%(2))

Clicking on the button opens a dialog allowing to add a \cn() escape sequence by selecting the desired color from a indexedcolor list box.

If the curve is an analytical function and you have defined a custom comment for it, by default it is this comment that will bedisplayed. In order to change this behavior you can use either "@D" to display the function title or "@X" for the analyticalexpression of the function.

If the Auto-update box is checked, the legend is updated each time a curve is added or removed from the plot layer.

The TeX Output option specifies if LaTeX special characters should be escaped or not when exporting to .tex files. If the textcontains LaTeX syntax (like superscripts, subscripts, etc...) and you want them to be interpreted by the LaTeX compiler, youshould check this option.

By pressing the Set As Default button, all text format options will be saved to the user preferences and will be applied to new textobjects. The Apply to... button can be used to apply these format options to all text objects in the active plot layer, the current plotwindow, or all plot windows in the project. The scope of application of the new format can be chosen from the list box below theApply to... button.

The Opacity of the Background color can have a value between 0 (transparent background) and 255 (completely opaque back-ground).

The text item can be modified in the text window. Several enhancements can be added to text:

• _text will draw the text as subscripts. You can insert this sequence by clicking on the button.

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• ^text will draw the text as superscripts. You can insert this sequence by clicking on the button.

• Clicking on the button, opens a dialog for selecting lower case Greek characters:

• Clicking on the button opens a dialog for selecting upper case Greek characters:

• Clicking on the integral symbol opens a dialog which allows selecting various mathematical symbols:

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• Clicking on the arrow icon opens a dialog which allows selecting various arrow symbols:

• <b>text</b> will draw the text with bold characters. You can insert this sequence by clicking on the button.

• <i>text</i> will draw the text with italic characters. You can insert this sequence by clicking on the button.

• <u>text</u> will draw the text with underlined characters. You can insert this sequence by clicking on the button.

5.42 Export ASCII Dialog

This dialog is activated by selecting the Export ASCII command from the File Menu. It is active if there is at least one tablewindow in the project.

This command is used to export all or a part of the data of a project to an ASCII file. Alternatively, you can also choose to exportthe tables/matrices to one of the following formats: TeX (.tex), Open Document Format (.odf) or as web pages (.html).

The file Name as well as the Path where the data will be saved can be chosen by pressing the file system browsing buttons at theright. They can also be edited manually. Please note that QtiPlot provides an auto-completion mechanism when editing the filepath.

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In the screenshot bellow, the names of the selected columns will be exported as the first line of the file. If the Include ColumnComments option were also checked then the comments displayed in the table header would also be exported as the second lineof the file. A TAB character will be used as a separator between columns values. Since the Export Selection option is checked,only the selected columns will be exported.

Figure 5.137: Export of a selection from a table to an ASCII file.

When the "Include Column Names" option is not checked, any column names will be ignored and the names "C1", "C2",... willbe used in the exported file. The formatting of the numbers in each table column is preserved during the export. Make surethat adequate precision has been set before exporting to insure that the ASCII representation of the numbers in the output file issufficiently accurate.

5.43 Import ASCII files

This dialog is activated by selecting the Import -> Import ASCII... command from the File Menu. The files are imported using aset of default options. All your changes to the default import parameters will be saved.

The file Name as well as the Path of the files to be imported can be chosen by pressing the file system browsing buttons at theright. They can also be edited manually. Please note that QtiPlot provides an auto-completion mechanism when editing the filepath.

This dialog can be used to import one or several ASCII files at the same time (their names must be separated by commas). Ifmultiple files are imported simultaneously and any of the names in the list contain the comma character, the file names must beenclosed in double quotes in order to be able to correctly perform the parsing of the file names. QtiPlot automatically adds thedouble quotes when you select the files to be imported using the file system browsing button.

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Figure 5.138: The dialog box.

You can define a custom file filter in the Format field in order to preselect files. For example, typing *.mydata will set a filter thatwill show only files of the form "XXX.mydata" in the file selection dialog.

Concerning the character which is used to separate column values, you must bear in mind that there is no grouping of separators,so if you use "SPACE", you must use only one separator between each column or check the Simplify white spaces option.

If your data files have a particular structure, for example if they begin with several lines describing your experiment, you mayskip the first n lines of the file. You can also skip all lines starting with a comment character/string. The comment string can becustomized using the Ignore lines starting with text edit box.

If you choose to use the first line to define column names and/or the second line as comments to be displayed in the table header,you must use the same separator between column names as that used between data columns.

If the files you want to import were created using a different convention for the decimal and thousands separator charactersthan the current setting, then the Decimal Separators option can be used to configure QtiPlot to use a matching convention.For example, when a comma character is used for the decimal point instead of the dot character, simply change the DecimalSeparators option to match. You can have QtiPlot ignore the Thousands separator altogether with the Omit thousands separatoroption.

Finally, you can specify the kind of data to be imported in each column by pressing the Column Types... button or by double-clicking on the column header in the preview table. A dialog will pop-up allowing you to choose a data type (the default datatype for each column is Text & Numeric) and a column format in the case of date/time columns.

The format string may be chosen from the list of predefined formats or may be edited in order to fit your particular data format.In this format string the following placeholders are recognized, all other input characters being treated as text:

d the day as number without a leading zero (1 to 31)

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dd the day as number with a leading zero (01 to 31)

ddd the abbreviated localized day name (e.g. ’Mon’ to ’Sun’)

dddd the long localized day name (e.g. ’Monday’ to ’Sunday’)

M the month as number without a leading zero (1-12)

MM the month as number with a leading zero (01-12)

MMM the abbreviated localized month name (e.g. ’Jan’ to ’Dec’)

MMMM the long localized month name (e.g. ’January’ to ’December’)

yy the year as two digit number (00-99)

yyyy the year as four digit number

h the hour without a leading zero (0 to 23 or 1 to 12 if AM/PM display)

hh the hour with a leading zero (00 to 23 or 01 to 12 if AM/PM display)

H the hour without a leading zero (0 to 23, even with AM/PM display)

HH the hour with a leading zero (00 to 23, even with AM/PM display)

m the minute without a leading zero (0 to 59)

mm the minute with a leading zero (00 to 59)

s the second without a leading zero (0 to 59)

ss the second with a leading zero (00 to 59)

z the milliseconds without leading zeroes (0 to 999)

zzz the milliseconds with leading zeroes (000 to 999)

AP or A interpret as an AM/PM time. AP must be either "AM" or "PM".

ap or a interpret as an AM/PM time. ap must be either "am" or "pm".

5.44 Import database

This dialog is activated by selecting the File -> Import -> Database... command. The dialog allows to choose the tables/views tobe imported from a database. You have the possibility to import individual tables or all tables at once by checking the box All. Ifthe New Folder option is checked the imported tables are moved into a subfolder inside the current folder of your project. Thename of this subfolder is generated automatically based on the name of the database.

If you choose to import an SQL database (MySQL, PostgreSQL or SQLite) or a Microsoft Access database on a Windowssystem, it is also possible to perform an SQL query on the database, prior to the import operation:

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Figure 5.139: SQL database table/view selection with query dialog.

On Linux or macOS systems it is not possible to perform an SQL query when importing Microsoft Access databases (.mdb).

Figure 5.140: Database table/view selection dialog on Linux and macOS systems.

5.45 Open TDMS File

This dialog is opened by selecting the Import -> NI (TDMS)... command from the File -> Import submenu and allows totalcontrol over the process of importing NI TDMS format files (*.tdms).

The controls in the upper side of the dialog provide basic information about the file being imported: its location (displayed in thePath label) and its size (displayed in the corresponding Size label).

The dialog also displays the structure of the TDMS file in a tree widget allowing the selection of the groups and channels to beimported. It is possible to enable/disable the import of an entire group or of individual channels by checking/unchecking thecorresponding box situated on the right side of the selection tree. The same result can be achieved by right-clicking on the nameof a group or channel and selecting the Import option from the pop-up menu.

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A double-click on the name of a channel opens an information message box displaing the number of data values in this channeltoghether with the list of its properties. The list of properties can also be displayed by right-clicking on the name of a channeland selecting the Properties option from the pop-up menu.

If the Preview box is checked QtiPlot displays a plot of the raw data values stored in the currently selected channel. The selectionof the channels can be done either with the mouse or using the up and down arrow keys. The preview image is not available forchannels containing strings or time stamps. If the raw data values have a complex type only the real part of the data is displayedby the preview plot.

Checking the Preview box also enables an input box that allows to limit the number of raw data values visible in the preview plot.By default this limit is set to one million. Choosing a limit lower than two automatically displays all data.

QtiPlot creates a new table for each group imported from the TDMS file. By checking the New Folder box these tables are movedinto a subfolder inside the current folder of your project. The name of the new subfolder is generated automatically based on thename of the TDMS file.

Figure 5.141: The Open TDMS File dialog box.

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Figure 5.142: The TDMS channel properties dialog.

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Chapter 6

Analysis of data and curves

6.1 Fast Fourier Transform

This function is accessed with the FFT... command, which is located in the Analysis Menu whenever a table or a plot is selected.The Fourier transform decomposes a signal into its elementary components by assuming that the signal x(t) can be described asa sum:

EQUATION 6.1: Fourier equation

in which are the frequencies, an are the amplitudes of each frequency and are the phases of each frequency. QtiPlot willcompute these parameters and build a new plot of the amplitude as a function of frequency.

This FFT was performed on a curve to extract it’s characteristic frequency components. The original signal is on the bottomplot, while the amplitude-frequency plot is on the top layer. In this example, the amplitude curve has been normalized, and the

frequencies have been shifted to obtain a centered x-scale.

Figure 6.1: An example of the FFT.

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The important parameters of the FFT can be modified using the FFT dialog, including the selection of an inverse FFT. An inverseFFT performed on the results of a forward FFT should result in the original signal. Frequently, it is useful to remove or modifysome of the frequency components before the inverse FFT is performed. This may be particularly useful when it is desirable toremove some known interference. A common example would be the removal of power-line interference (usually 50 or 60 Hz,depending upon where you live). You should remember that this will also remove any real portions of the signal that happen tobe at that same frequency. Care should be used when doing this.

6.2 Correlation

This function is accessed with the Correlate command. It is located in the Analysis Menu whenever a table is selected. Thecorrelation function, also known as the covariance function, is used to test the similarity of two signals x(t) and y(t). It iscomputed as:

EQUATION 6.2: Covariance function of two signals x(t) and y(t)

in which and are the mean values of the signals x(t) and y(t), respectively.

If the number of points is N, the function will be computed between -N/2 and N/2. The abscissae are therefore point indexes andnot t values.

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The first plot shows the two signals, the second one is the correlation function between the two signal which shows that there arecorrelations, and the third one is the Fourier transform which is done to extract the characteristic frequencies of the correlation

function.

Figure 6.2: An example of a correlation between two sine functions.

The correlation of a signal with itself can also be performed and is frequently used in spectral analysis (it is then called autocor-relation or autocovariance function).

6.3 Convolution

.

6.4 Deconvolution

.

6.5 The Fit Wizard

This function is accessed with the Fit Wizard... command. It is located in the Analysis Menu whenever a table is selected.

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The results are shown in the log window, the curve is plotted in the active window, and a table is created to store the fit.

Figure 6.3: The results of the Fit Wizard....

6.6 Fitting to specific curves

QtiPlot includes quick access to the most useful functions for fitting.

6.6.1 Fitting to a line

This command is used to fit a curve which has a linear shape.

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Figure 6.4: The results of a Fit Linear.

The results will be given in the Log panel:

6.6.2 Fitting to a polynomial

This command is used to fit a polynomial function to data which has a curvilinear shape. It opens the Polynomial Fit Optionsdialog, allowing you to choose the curve to fit, the order of the polynomial function to use, the number of points of the resultingcurve and the abscissa limits for the fit.

The results of the fit are displayed in the Log panel

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Figure 6.5: The results of a Fit Polynomial..., showing the initial data, the curve added to the plot, and the results in the log panel.

6.6.3 Fitting to a Boltzmann function

This command is used to fit a curve which has a sigmoidal shape. The function used is:

EQUATION 6.3: Boltzmann equation

in which A1 is the low Y limit, A2 is the high Y limit, x0 is the inflexion (half amplitude) point and dx is the width.

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Figure 6.6: The results of a Fit Boltzmann (sigmoidal).

When the X axis is using a logarithmic scale, the Fit Boltzmann (sigmoidal) command uses the Logistical equation for fitting:

EQUATION 6.4: Logistic dose response equation

where A1 is the initial Y value, A2 is the final Y value, x0 is the inflexion point (center) and p is the power.

6.6.4 Fitting to a Gauss function

This command is used to fit a curve which has a bell shape. The function used is:

EQUATION 6.5: Gauss equation

in which A is the height, w is the width, xc is the center and y0 is the Y-values offset.

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Figure 6.7: The results of a Fit Gaussian.

6.6.5 Fitting to a Lorentz function

This command is used to fit a curve which has a bell shape. The function used is:

EQUATION 6.6: Lorentz equation

in which A is the area, w is the width, xc is the center and y0 is the Y-values offset.

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Figure 6.8: The results of a Fit Lorentzian.

6.6.6 Fitting to a PsdVoigt1 function

This command is used to fit a curve with a Pseudo-Voigt function which is a linear combination of Gaussian and Lorentzianfunctions:

EQUATION 6.7: PsdVoigt1 equation

The parameters of the PsdVoigt1 function have the following meaning: y0 is the Y-values offset, A is the area, w is the width(FWHM), xc is the center and mu is a profile shape factor.

6.6.7 Fitting to a PsdVoigt2 function

This command is used to fit a curve with a Pseudo-Voigt function which is a linear combination of Gaussian and Lorentzianfunctions with different FWHM:

EQUATION 6.8: PsdVoigt2 equation

The parameters of the PsdVoigt2 function have the following meaning: y0 is the Y-values offset, A is the area, wG is the GaussianFWHM, wL is the Lorentzian FWHM, xc is the center and mu is a profile shape factor.

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6.7 Multi-Peaks fitting

This kind of fitting allows to fit your data points to a sum of N Gaussian, Lorentzian or Pseudo-Voigt functions.

The first step is to specify the number of peaks. Then you must define the position of each peak on the curve. This is done byclicking on the plot, then validate your choice for each peak with the ENTER key.

Figure 6.9: The results of a Fit Multi-peak -> Gaussian....

6.8 Filtering of data curves

In this section, it will be assumed that you have the following data curve:

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This signal has a power spectrum which contains both high and low frequencies. We can analyze this by doing a FFT on the datacurve, this leads to the following figure:

The next sections will show the influence of the different filters on this data curve.

6.8.1 FFT low pass filter

This filter cuts high frequencies from a signal. You just have to select the cut-off frequency of the filter. Let us assume that wewant to keep the frequencies below 1 Hz, we will obtain:

Figure 6.10: Signal after a FFT low pass filter

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The power spectrum of this new signal shows that the frequencies below 1 Hz.

6.8.2 FFT high pass filter

This filter cuts low frequencies from a signal. You just have to select the cut-off frequency of the filter. Let us assume that wewant to keep the frequencies above 1 Hz, we will obtain:

Figure 6.11: Signal after a FFT high pass filter

The power spectrum of this new signal shows that the frequencies above 1 Hz remain.

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6.8.3 FFT band pass filter

This filter cuts both low and high frequencies from a signal while leaving frequencies in the pass band. You just have to selectthe high and low cut-off frequencies of the filter. Let us assume that we want to keep the frequencies between 1.5 and 3.5 Hz, wewill obtain:

Figure 6.12: Signal after a FFT band pass filter

The power spectrum of this new signal shows that only frequencies in the pass band remain (2 and 3 Hz).

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6.8.4 FFT block band filter

This filter keeps the low and high frequencies in a signal while cutting frequencies in the stop band. You just have to select thehigh and low cut-off frequencies of the filter. Let us assume that we want to remove the frequencies between 1.5 and 3.5 Hz, wewill obtain:

Figure 6.13: Signal after a FFT block band filter

The power spectrum of this new signal shows that only the frequencies below 1.5 Hz and above 3.5 Hz remain.

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6.9 Interpolation

The interpolation command will create a new data curve with a high number of points generated by interpolation of your data.The dialog box allows you to define the number of points (default value = 1000), the method used for interpolation, the intervalof X-values to interpolate over and the color of the interpolated curve. In addition to the new curve in the active plot, a new tablewill be created containing the data for the curve.

Three interpolation methods are available. The first is a linear method. In this case, interpolated data points are placed along thestraight between every two adjacent values of your data. The second is the method of cubic splines, in which case at least 4 pointsare needed. The last method, Akima, is a polynomial interpolation. Refer to the corresponding sections of the GNU ScientificLibrary for more details.

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Figure 6.14: Comparison of the three methods of interpolation

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Chapter 7

Mathematical Expressions and Scripting

QtiPlot supports two different interpreters for evaluating mathematical expressions and for executing scripts: muParser andPython. muParser can be only used for the evaluation of mathematical expressions, whereas Python can be used to execute scrips.The default interpreter is muParser therefore if you want to execute scripts you should first enable the Python scripting enginevia the Scripting language dialog. Also, you can define the default scripting interpreter via the General tab of the Preferencesdialog.

7.1 muParser

The constants _e=e=E and _pi=pi=PI=Pi are defined, as well as the following fundamental physical constants, operators andfunctions. Please note that the fundamental constants cannot be redefined. Doing so will raise an error message. The values ofthe physical constants listed bellow are defined using the standard MKSA unit system (meters, kilograms, seconds, amperes):

Name Descriptionc The speed of light in vacuumeV The energy of 1 electron voltg The standard gravitational acceleration on EarthG The gravitational constanth Planck’s constanthbar Planck’s constant divided by 2 pik The Boltzmann constantNa Avogadro’s numberR0 The molar gas constantV0 The standard gas volumeRy The Rydberg constant, in units of energy

Table 7.1: muParser: Predefined Fundamental Physical Constants in the standard MKSA unit system

7.2 Python

This module provides bindings to the Python programming language. Basic usage in the context of QtiPlot will be discussedbelow, but for more in-depth information on the language itself, please refer to its excellent documentation.

7.2.1 The Initialization File

The qtiplotrc.py file allows you to customize the Python environment, import modules and define functions and classes thatwill be available in all of your projects. If QtiPlot was built using Qt 4 library, the name of the default initialization file is

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Name Description+ Addition- Subtraction* Multiplication/ Division% Modulus operator (returns the remainder of a when divided by b)ˆ Exponentiation (raise a to the power of b)< less than (returns 0 or 1)<= less than or equal (returns 0 or 1)== equal (returns 0 or 1)>= greater than or equal (returns 0 or 1)> greater than (returns 0 or 1)!= not equal (returns 0 or 1)

Table 7.2: muParser: Supported Mathematical Operators

qtiplotrc_qt4.py.

The default initialization file shipped with QtiPlot imports Python’s standard math functions as well as (if available) specialfunctions from SciPy, the symbolic mathematics library SymPy and helper functions for RPy2. Also, it creates some handyshortcuts, like table("table1") for qti.app.table("table1").

When activating Python support, QtiPlot searches the initialization file in a default folder, which can be customized via the FileLocations tab of the Preferences dialog. If the initialization file is not found, QtiPlot will issue a warning and muParser will bekept as the default interpreter.

Files ending in .pyc are compiled versions of the .py source files and therefore load a bit faster. The compiled version will be usedif the source file is older or nonexistent. Otherwise, QtiPlot will try to compile the source file (if you’ve got write permissionsfor the output file).

7.2.2 Python Basics

Mathematical expressions work largely as expected. However, there’s one caveat, especially when switching from muParser(which has been used exclusively in previous versions of QtiPlot): aˆb does not mean "raise a to the power of b" but rather"bitwise exclusive or of a and b"; Python’s power operator is **. Thus:

2^3 # read: 10 xor 11 = 01#> 12**3#> 8

One thing you have to know when working with Python is that indentation is very important. It is used for grouping (most otherlanguages use either braces or keywords like do...end for this). For example,

x=23for i in (1,4,5):

x=i**2print(x)

will do what you would expect: it prints out the numbers 1, 16 and 25; each on a line of its own. Deleting just a bit of space willchange the functionality of your program:

x=23for i in (1,4,5):

x=i**2print(x)

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Name Descriptionabs(x) absolute value of xacos(x) inverse cosineacosh(x) inverse hyperbolic cosineasin(x) inverse sineasinh(x) inverse hyperbolic sineatan(x) inverse tangentatanh(x) inverse hyperbolic tangentavg(x1,x2,x3,...) average value, this command accept a list of arguments separated by commasbessel_j0(x) Regular cylindrical Bessel function of zeroth order, J0(x).bessel_j1(x) Regular cylindrical Bessel function of first order, J1(x).bessel_jn(x,n) Regular cylindrical Bessel function of nth order, Jn(x).bessel_y0(x) Irregular cylindrical Bessel function of zeroth order, Y0(x) for x>0.bessel_y1(x) Irregular cylindrical Bessel function of first order, Y1(x) for x>0.bessel_yn(x,n) Irregular cylindrical Bessel function of nth order, Yn(x) for x>0.beta (a,b) Computes the Beta Function, B(a,b) = Gamma(a)*Gamma(b)/Gamma(a+b) for a > 0 and b > 0.cos(x) cosine of xcosh(x) hyperbolic cosine of xerf(x) error function of xerfc(x) Complementary error function erfc(x) = 1 - erf(x).erfz(x) The Gaussian probability density function Z(x).erfq(x) The upper tail of the Gaussian probability function Q(x).exp(x) Exponential function: e raised to the power of x.gamma(x) Computes the Gamma function, subject to x not being a negative integer

gammaln(x) Computes the logarithm of the Gamma function, subject to x not a being negative integer. For x<0,log(|Gamma(x)|) is returned.

hazard(x) Computes the hazard function for the normal distribution h(x) = erfz(x)/erfq(x).ln(x) natural (base e) logarithm of xlog(x) natural (base e) logarithm of xlog10(x) decimal (base 10) logarithm of xlog2(x) base 2 logarithm of xmin(x1,x2,x3,...) Minimum of the list of argumentsmax(x1,x2,x3,...) Maximum of the list of argumentsrint(x) Round to nearest integer.sign(x) Sign function: -1 if x<0; 1 if x>0.sin(x) sine of xsinh(x) hyperbolic sine of xsqrt(x) square root of xtan(x) tangent of xtanh(x) hyperbolic tangent of x

Table 7.3: muParser: Mathematical Functions

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Name Description

cell(a,b) In the context of a matrix, returns the value at row a and column b. In the context of a table, returns the valueat column a and row b (remember that tables use column logic). Everywhere else, this function is undefined.

col(c) Only works in the context of a table. Returns the value at column c and row i (the current row) in the contexttable. c can either be the column’s number, or its name in doublequotes.

if(e1,e2,e3) if e1 is true, e2 is executed else e3 is executed.

tablecol(t,c) Only works in the context of a table. Returns the value at column c and row i (the current row) in the table t.t is the table’s name in doublequotes, c is either the column’s number or its name in doublequotes.

interp(y,i,x)Takes a column name y, in doublequotes, and the corresponding abscissae stored in the column with index ifrom the same data table and linearly interpolates an ordinate at a given abscissa x. Only works in the contextof a table.

AVG(n,i,j) The average of all cells from row i to j in column with name n (in doublequotes). A negative value of the endrow j means the last table row. Only works in the context of a table.

MIN(n,i,j) The minimum value of all cells from row i to j in column with name n (in doublequotes). A negative valueof the end row j means the last table row. Only works in the context of a table.

MAX(n,i,j) The maximum value of all cells from row i to j in column with name n (in doublequotes). A negative valueof the end row j means the last table row. Only works in the context of a table.

SD(n,i,j) The standard deviation of all cells from row i to j in column with name n (in doublequotes). A negative valueof the end row j means the last table row. Only works in the context of a table.

SUM(n,i,j) The sum of all cells from row i to j in column with name n (in doublequotes). A negative value of the endrow j means the last table row. Only works in the context of a table.

rms(n,i,j) The root mean square of all cells from row i to j in column with name n (in doublequotes). A negative valueof the end row j means the last table row. Only works in the context of a table.

Table 7.4: muParser: Other functions

will print out only one number - no, not 23, but rather 25. This example was designed to also teach you something about variablescoping: There are no block-local variables in Python. All statements outside of any function use module scope; that is, variablesattached to one column script or script window. All statements inside a function use that function’s "local" scope, but they canalso read module variables. System-wide globals are stored in the special variable globals. To store your own:

globals.mydata = 5print globals.mydata

Global scope rules recently changed In older versions, write this instead:

global mydatamydata = 5print mydata

7.2.3 Defining Functions and Control Flow

The basic syntax for defining a function (for use within one particular note, for example) is

def answer():return 42

If you want your function to be accessible from other modules, you have to add it to the globals:

def answer():return 42

globals.answer = answer

If you have an older versions of QtiPlot, you have to declare it global before the definition:

global answerdef answer():

return 42

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You can add your own function to QtiPlot’s function list. We’ll also provide a documentation string that will show up, forexample, in the "set column values" dialog:

def answer():"Return the answer to the ultimate question about life, the universe and everything."return 42

qti.mathFunctions["answer"] = answer

If you want to remove a function from the list, do:

del qti.mathFunctions["answer"]

Global scope rules recently changed In older versions, a function’s local scope hid the module scope. That means that if youentered a function definition in a Note, you would not be able to access (neither reading nor writing) Note-local variables fromwithin the function. However, you could access global variables as usual.

If-then-else decisions are entered as follows:

if x>23:print(x)

else:print("The value is too small.")

You can do loops, too:

for i in range(1, 11):print(i)

This will print out the numbers between 1 and 10 inclusively (the upper limit does not belong to the range, while the lower limitdoes).

7.2.4 Mathematical Functions

Python comes with some basic mathematical functions that are automatically imported (if you use the initialization file shippedwith QtiPlot). Along with them, the constants e (Euler’s number) and pi (the one and only) are defined.

7.2.5 Accessing QtiPlot’s objects from Python

We will assume that you are using the initialization file shipped with QtiPlot. Accessing the objects in your project is straight-forward,

t = table("Table1")m = matrix("Matrix1")g = graph("Graph1")p = plot3D("Graph2")n = note("Notes1")# get a pointer to the QTextEdit object used to display information in the results log ←↩

window:log = resultsLog()# display some information in the data display toolbar:displayInfo(text)# get a pointer to the QLineEdit object in the data display toolbar and access the ←↩

information displayed:info = infoLineEdit()text = info.text()

as is creating new objects:

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Name Descriptionacos(x) inverse cosineasin(x) inverse sineatan(x) inverse tangentatan2(y,x) equivalent to atan(y/x), but more efficientceil(x) ceiling; smallest integer greater or equal to xcos(x) cosine of xcosh(x) hyperbolic cosine of xdegrees(x) convert angle from radians to degreesexp(x) Exponential function: e raised to the power of x.fabs(x) absolute value of xfloor(x) largest integer smaller or equal to xfmod(x,y) remainder of integer division x/y

frexp(x) Returns the tuple (mantissa,exponent) such that x=mantissa*(2**exponent) where exponent is an integer and0.5 <=abs(m)<1.0

hypot(x,y) equivalent to sqrt(x*x+y*y)ldexp(x,y) equivalent to x*(2**y)log(x) natural (base e) logarithm of xlog10(x) decimal (base 10) logarithm of xmodf(x) return fractional and integer part of x as a tuplepow(x,y) x to the power of y; equivalent to x**yradians(x) convert angle from degrees to radianssin(x) sine of xsinh(x) hyperbolic sine of xsqrt(x) square root of xtan(x) tangent of xtanh(x) hyperbolic tangent of x

Table 7.5: Python: Supported Mathematical Functions

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# create an empty table named "tony" with 5 rows and 2 columns:t = newTable("tony", 5, 2)# use defaultst = newTable()# create an empty matrix named "gina" with 42 rows and 23 columns:m = newMatrix("gina", 42, 23)# use defaultsm = newMatrix()# create an empty graph windowg = newGraph()# create a graph window named "test" with two layers disposed on a 2 rows x 1 column gridg = newGraph("test", 2, 2, 1)# create an empty 3D plot window with default titlep = newPlot3D()# create an empty note named "momo"n = newNote("momo")# use defaultsn = newNote()

The currently selected Table/Matrix etc. can be accessed with the following commands:

t = currentTable()m = currentMatrix()g = currentGraph()n = currentNote()

The functions will only return a valid object if a window of the wanted type is actually selected. You can check if the object isvalid with a simple if clause:

if isinstance(t,qti.Table): print "t is a table"

Every piece of code is executed in the context of an object which you can access via the self variable. For example, enteringself.cell("t",i) as a column formula is equivalent to the convenience function col("t"). Once you have establishedcontact with a MDI window, you can modify some of its properties, like the name, the window label, the geometry, etc.. Forexample, here’s how to rename a window, change its label and the way they are displayed in the window title bar, the so calledcaption policy:

t = table("Table1")setWindowName(t, "toto")t.setWindowLabel("tutu")t.setCaptionPolicy(MDIWindow.Both)

The caption policy can have one of the following values:

1. Name -> the window caption is determined by the window name

2. Label -> the caption is determined by the window label

3. Both -> caption = "name - label"

It is also possible to add comments to a project window. The comments may include line breaks, contrary to the window label:

t = table("Table1")t.setWindowComment("Experiment name: ...\nDate: ...\nProcedure: ...\n")print t.windowComment()

Here’s how you can access and modify the geometry of a window in the project:

t = table("Table1")t.setGeometry(10, 10, 800, 600)print t.x(), t.y(), t.width(), t.height()

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It is possible to modify the status (minimized, maximized, normal) of a window in the project:

t = table("Table1")t.showMinimized()t.showMaximized()t.showNormal()

It is also possible to hide a window:

hideWindow(table("Table1"))

...and to restore its visibility:

table("Table1").setVisible(True)

For a fast editing process, you can create template files from existing tables, matrices or plots. The templates can be used lateron in order to create customized windows very easily:

saveAsTemplate(graph("Graph1"), "my_plot.qpt")g = openTemplate("my_plot.qpt")

Also, you can easily clone a MDI window:

g1 = clone(graph("Graph1"))

If you want to delete a project window, you can use the close() method. You might want to deactivate the confirmationmessage, first:

w.confirmClose(False)w.close()

All QtiPlot subwindows are displayed in a QMdiArea. You can get a pointer to this object via the workspace() method. Thiscan be particularly usefull if you need to customize the behavior of the workspace via your scripts. Here follows a small examplescript that pops-up a message displaying the name of the active MDI subwindow each time a new window is activated:

def showMessage():QtGui.QMessageBox.about(qti.app, "", workspace().activeSubWindow().objectName())

QtCore.QObject.connect(workspace(), QtCore.SIGNAL("subWindowActivated(QMdiSubWindow *)"), ←↩showMessage)

If you want to automatically arrange all the subwindows in the workspace you can use the following methods:

tileWindows()cascadeWindows()

It is possible to access the list of all MDI window objects in a QtiPlot project:

for w in qti.app.windows():print w.objectName()

...or the list of selected MDI windows in the project explorer:

for w in qti.app.selectedExplorerWindows():print w.objectName()

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7.2.6 User settings

It is worth knowing that it is possible to export and store the custom application settings to an *.ini file:

qti.app.saveSettingsAs("/Users/ion/Desktop/myPrefs.ini")

Of course, it is possible to load custom application settings from such an *.ini file or from an *.ini file that has been previouselycreated via the preferences dialog, using the Save As... button:

qti.app.readSettings("/Users/ion/Desktop/myPrefs.ini")

7.2.7 Project Folders

Storing your data tables/matrices and your plots in folders can be very convenient and helpful when you’re analyzing loads ofdata files in the same project. New objects will always be added to the active folder. You can get a pointer to it via:

f = activeFolder()

The functions table, matrix, graph and note will start searching in the active folder and, failing this, will continue with a depth-firstrecursive search of the project’s root folder, given by:

f = rootFolder()

In order to access subfolders and windows, the following functions are provided:

f1 = folder("folder1")f2 = f.folder("folder2", caseSensitive=True, partialMatch=False)f3 = f.folders()[2] # f3 is the 3rd subfolder of parent folder ft = f.table(name, recursive=False)m = f.matrix(name, recursive=False)g = f.graph(name, recursive=False)n = f.note(name, recursive=False)lst = f.windows()for w in lst:

print w.objectName()

If you supply True for the recursive argument, a depth-first recursive search of all subfolders will be performed and the firstmatch returned.

New folders can be created using:

newFolder = addFolder("New Folder", parentFolder = 0)

If the parentFolder is not specified, the new folder will be added as a subfolder of the project’s root folder. When youcreate a new folder via a Python script, it doesn’t automatically become the active folder of the project. You have to set thisprogramatically, using:

changeFolder(newFolder, bool force=False)

Folders can be deleted using:

deleteFolder(folder)

It is possible to copy folders within a project:

copyFolder(folder("source"), folder("destination"))

Project windows can be moved between existing folders using:

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table("Table1").moveTo(folder("folder1"))graph("Graph1").moveTo(addFolder("folder2"))

You can save a window or a folder as a project file, and of course, you can also save the whole project:

saveWindow(table("Table1"), "Table1.qti", compress=False)saveFolder(folder, "new_file.qti", compress=False)saveProjectAs("new_file_2.qti", compress=False)saveProject()print projectName()

If compress is set to True, the project file will be archived to the .gz format, using zlib.

Also, you can load a QtiPlot or an Origin project file into a new folder. The new folder will have the base name of the project fileand will be added as a subfolder to the parentFolder or to the current folder if no parent folder is specified.

newFolder = appendProject("projectName", parentFolder = 0)

If you don’t want to be asked for confirmation when a table/matrix is renamed during this operation, or when deleting a foldervia a Python script, you must change your preferences concerning prompting of warning messages, using the Preferences dialog("Confirmations" tab).

Folders store their own log information containing the results of the analysis operations performed on the child windows. Thisinformation is updated in the result log window each time you change the active folder in the project. You can access andmanipulate these log strings via the following functions:

text = folder.logInfo()folder.appendLogInfo("Hello!")folder.clearLogInfo()

Finally, it is worth mentioning that it is possible to access the list of all selected folder items in the project explorer:

for folder in qti.app.selectedFolders():print folder.name()

7.2.8 Working with Tables

We’ll assume that you have assigned some table to the variable t. You can access its numeric cell values with

t.cell(col, row)# andt.setCell(col, row, value)

Whenever you have to specify a column, you can use either the column name (as a string) or the consecutive column number(starting with 1). Row numbers also start with 1, just as they are displayed. In many places there is an alternative API whichrepresents a table as a Python sequence is provided. Here rows are addressed by Python indices or slices which start at 0. Theseplaces are marked as such.

If you want to work with arbitrary texts or the textual representations of numeric values, you can use:

t.text(col, row)# andt.setText(col, row, string)

An alternative way to get/set the value of a cell is using the getter/setter functions bellow. Assigning a None value will clear thecell:

t.cellData(col, row)# andt.setCellData(col, row, value)

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Based on the type of the column, QtiPlot handles all the casting under the hood and throws an TypeError if setting the datafor a cell isn’t possible. The type of a column can be one of the following:

Table.Numeric: returns/accepts only numerical values.

Table.Text: returns/accepts only text strings.

Table.Date: returns/accepts Python datetime.datetime objects and also accepts a QDateTime.

import timefrom datetime import datetimet = newTable("datetime", 2, 1)t.setColDateFormat(1, "dd/MM/yyyy")t.setCellData(1, 1, datetime.utcnow()) # from Python datetime objectt.setCellData(1, 2, QDateTime.currentDateTime()) # from QDateTime object

Table.Time: returns/accepts datetime.time objects and also accepts a QTime.

import timefrom datetime import datetimet = newTable("time", 2, 1)t.setColTimeFormat(1, "hh:mm:ss")t.setCellData(1, 1, datetime.now().time()) # from Python time objectt.setCellData(1, 2, QTime.currentTime()) # from QTime object

Table.Month: accepts any numerical values, including floating point values and internally transforms them to integer valuescorresponding to the months of the year: 1 (January) to 12 (December, for which also 0 is accepted).

Table.Day: accepts any numerical values, including floating point values and internally transforms them to integer values cor-responding to the days of the week: 1 (monday) to 7 (sunday, for which also 0 is accepted).

Table.TextAndNumeric: returns/accepts both numerical values and text strings. It is the default type.

You can set the format of a column to text using:

t.setColTextFormat(col)

Or you can adjust the numeric format:

t.setColNumericFormat(col, format, precision)

were col is the number of the column to adjust and precision states the number of digits. The format can be one of thefollowing:

Table.Default (0) standard format

Table.Decimal (1) decimal format with precision digits

Table.Scientific (2) scientific format

You can reset the Table.TextAndNumeric type for a column if it was modified previously using the following function:

t.setColTextNumericFormat(col, format, precision)

In the same way you can set a column to hold a date. Here the text of a cell is interpreted using a format string:

t.setColDateFormat(col, format)t.setColDateFormat("col1", "yyyy-MM-dd HH:mm")

were col is the name/number of a column and format the format string. In the format string the following placeholders arerecognized, all other input characters being treated as text:

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d the day as number without a leading zero (1 to 31)

dd the day as number with a leading zero (01 to 31)

ddd the abbreviated localized day name (e.g. ’Mon’ to ’Sun’)

dddd the long localized day name (e.g. ’Monday’ to ’Sunday’)

M the month as number without a leading zero (1-12)

MM the month as number with a leading zero (01-12)

MMM the abbreviated localized month name (e.g. ’Jan’ to ’Dec’)

MMMM the long localized month name (e.g. ’January’ to ’December’)

yy the year as two digit number (00-99)

yyyy the year as four digit number

h the hour without a leading zero (0 to 23 or 1 to 12 if AM/PM display)

hh the hour with a leading zero (00 to 23 or 01 to 12 if AM/PM display)

H the hour without a leading zero (0 to 23, even with AM/PM display)

HH the hour with a leading zero (00 to 23, even with AM/PM display)

m the minute without a leading zero (0 to 59)

mm the minute with a leading zero (00 to 59)

s the second without a leading zero (0 to 59)

ss the second with a leading zero (00 to 59)

z the milliseconds without leading zeroes (0 to 999)

zzz the milliseconds with leading zeroes (000 to 999)

AP or A interpret as an AM/PM time. AP must be either "AM" or "PM".

ap or a interpret as an AM/PM time. ap must be either "am" or "pm".

Analog you can say that a text column should hold a time only...

t.setColTimeFormat(col, format)t.setColTimeFormat(1, "HH:mm:ss")

... a month ...

t.setColMonthFormat(col, format)t.setColMonthFormat(1, "M")

Here the format is the following:

M Only the first letter of the month, i.e. "J"

MMM The short form, like "Jan"

MMMM The full name, "January"

... or the day of week:

t.setColDayFormat(col, format)t.setColDayFormat(1, "ddd")

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Here the format is the following:

d Only the first letter of the day, i.e. "M"

ddd The short form, like "Mon"

dddd The full name, "Monday"

If you need all the data of a row or column you can use the rowData() and colData() methods. This is much faster theniterating manually over the cells. Alternatively you can use the [] operator in combination with Python indices or slices, whichstart at 0.

valueList = t.colData(col) # col may be a string or a number starting at 1rowTuple = t.rowData(row) # row number starting at 1rowTuple = t[idx] # row index starts at 0rowTupleList = t[slice]

A Table is iterable. The data is returned row wise as tuple.

for c1, c2, c3 in t:# do stuff, assuming t has three columns

It is possible to assign row, random or normal random values to a complete column or to a subset of rows in a column:

t.setRowValues(1, 1, 15)#startRow = 1, endRow = 15t.setRandomValues(col, startRow = 1, endRow = -1)t.setNormalRandomValues(col, startRow = 1, endRow = -1, standardDeviation = 1.0)

Assigning values to a complete row or column is also possible. While the new row data has to be a tuple which length mustmatch the column number, column data just has to be iteratable. If the iterator stops before the end of the table is reached, aStopIteration exception is raised. In combination with the offset this allows to fill a column chunk wise. A positiveoffset starts filling the column after this row number. A negative offset ignores the first values of the iterator.

t.setColData(col, iterableValueSequence, offset=0)# just fill the first column with a list of values, staring at row 6t.setColData(1, [12,23,34,56,67], 5)# fill the second column with Fibonacci numbers, omitting the first three.def FibonacciGenerator():

a, b = 1, 1while True:a, b = b, a+byield a

t.setColData(2, FibonacciGenerator(), -3)t.setRowData(row, rowTuple) # row starts at 1# assuming t has exactly two columns...t.setRowData(2, (23, 5)) # fill the second rowt[1] = 23, 5 # using a Python index, starting at 0# adding a new row and set it’s valuest.appendRowData(rowTuple)

The number of columns and rows of a table can be accessed or modified using:

t.numRows() # same as len(t)t.numCols()t.setNumRows(number)t.setNumCols(number)

You can add a new column at the end of the table using the addColumn() function. This function returns a reference to thenew column object.

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c1 = t.addColumn()c1.setName("A")

c2 = addColumn(Table.X)c2.setName("X")

It is possible to insert new columns before a startColumn using the functions below:

t.insertColumns(startColumn, count)

Adding an empty row at the end of the table is done with the addRow() method. It returns the new row number.

newRowIndex = t.addRow()

It is also possible to swap two columns using:

t.swapColumns(column1, column2)

You can delete a column or a range of rows using the functions below:

t.removeCol(number)t.deleteRows(startRowNumber, endRowNumber)

It is also possible to use Python’s del statement to remove rows. Note that in this case a Python index or slice (instead of rownumbers) is used, which start at 0.

del t[5] # deletes row 6del t[0:4] # deletes row 1 to 5

Column names can be read and written with:

t.colName(number)t.colNames()t.setColName(col, newName, enumerateRight=False)t.setColNames(newNamesList)

When setting a column name, please note that, for internal consistency reasons, the underscore character is not allowed and isautomatically replaced with a minus sign.

If enumerateRight is set to True, all the table columns starting from index col will have their names modified to acombination of the newName and a numerical increasing index. If this parameter is not specified, by default it is set to False.The plural forms get/set all headers at once.

Other column properties like the long name, the unit and the comment can be read/modified using the following methods:

t.setColLongName(1, "Distance")print t.colLongName(1)t.setColUnit(1, "nm")print t.colUnit(1)t.setColComment(1, "Experiment no. 10")print t.colComment(1)

You can enable/disable the display of these header label rows via the following functions:

t.showLongName(True)t.showUnits(False)t.showComments(True)

You can change the plot role (abscissae, ordinates, error bars, etc...) of a table column col using:

t.setColumnRole(col, role)print t.columnRole(col)

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where role specifies the desired column role:

0. Table.None

1. Table.X

2. Table.Y

3. Table.Z

4. Table.xErr

5. Table.yErr

6. Table.Label

You can normalize a single column or all columns in a table:

t.normalize(col)t.normalize()

Sort a single or all columns:

t.sortColumn(col, order = Qt.AscendingOrder)t.sort(type = Table.IndependentSort, order = Qt.AscendingOrder, leadingColumnName = "")

where the variable type can take one of the following values:

0. Table.IndependentSort

1. Table.DependentSort

and the order argument can be:

0. Qt.AscendingOrder

1. Qt.DescendingOrder

The small script bellow demonstrates how to use the sort method in order to perform a dependent sort in descending order on anentire table using a leading column:

t = newTable()t.setColName(1, "LeadCol")t.setRowValues(1)t.setRowValues(2)t.sort(Table.DependentSort, Qt.DescendingOrder, "LeadCol")

It is possible to customize the alignment of the text from the table cells which by default is set to Qt.AlignCenter:

t.setAlignment(Qt.AlignLeft) # for all table columnst.setAlignment(Qt.AlignRight, True) # for selected columns only

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7.2.8.1 Columns

It is also possible to manipulate individual table columns using their index. Column indices start at 1:

t = newTable("test", 10, 2)c1 = t.column(1)c1.setName("A")c2 = t.column(2)c2.setName("Date")

Column objects can also be accessed by their name. For example using the test table created with the script above, one gets areferrence to the column objects as follows:

c1 = t.column("A")c2 = t.column("Date")

Please beware that the column method used above returns a null reference if the table doesn’t contain a column with the nameyou indicated. Once you have a valid reference to a column object, c, you can access all its properties using the following getterfunctions:

c.name() # column short namec.longName() # column long namec.fullName() # returns tableName_shortNamec.unit()c.comment()c.command() # the formula set for the columnc.formatInfo() # the format string in case the column type is date/timec.numericPrecision() # the number of significant digitsc.numericFormat()c.alignment() # alignment of the text: Qt.AlignLeft, Qt.AlignCenter or Qt.AlignRightc.type()c.plotRole()c.isReadOnly()c.width()c.size() # returns the number of rowsc.isEmpty() # returns True if all cells in the column are emptyc.lastValidRow() # index of the last non empty cell starting from the bottomc.hasOnlyTextValues() # returns True if all cells have string valuesc.index() # column index in the parent table (leftmost column has index 1)

It is of course possible to modify the above properties using the corresponding setter functions:

c.setName("A")c.setLongName("test long name")c.setUnit("cm")c.setComment("column comment")c.updateHeaderView() # makes the changes visible in the table headerc.setCommand("sin(0.1*i)")c.setDateFormat("dd/MM/yyyy") # set format to Table.Date and format string to "dd/MM/yyyy"c.setTimeFormat("hh:mm:ss")# set format to Table.Time and format string to "hh:mm:ss"c.setMonthFormat("MMMM") # set Table.Month format; other format strings: "M" and "MMM"c.setDayFormat("dddd") # set Table.Day format; other format strings: "d" and "ddd"c.setNumericPrecision(10)c.setNumericFormat(Table.Decimal, 7) # set decimal format with 7 precision digitsc.setType(Table.Text) # set text formatc.setPlotRole(Table.X)c.setReadOnly()c.setReadOnly(False) # reenable column modificationsc.setWidth(90)c.setAlignment(Qt.AlignRight)c.setHidden() # hides columnc.setHidden(False) # makes column visible

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When setting a column name, please note that, for internal consistency reasons, the underscore character is not allowed and isautomatically replaced with a minus sign.

Please note that after setting a new column formula you need to trigger a recalculation of the cell values:

t = newTable("test", 30, 2)c = t.column(2)c.setCommand("sin(0.1*i)")t.recalculate(c.index())

It is straightforward to access cell values using their index, but you must be aware of the fact that for all column functions therow indices start at zero, contrary to table functions where indices start at 1:

val = c.value(0) # returns the value of the 1st cell as a doublestring = c.text(0) # returns the text string displayed in the 1st cell

It is also possible to get a Python list with the values from a range of cells or from the entire column:

print c.values(1) # all cells starting with 2nd rowprint c.values(1, 2) # values in 2nd and 3rd rowprint c.values() # all column values

The value of a column cell can be modified using the following setter functions:

c.setValue(0, 1178.14)c.setText(0, "text string")

It is also possible to fill a range of cells or the whole column with values from a Python list:

t = newTable("test", 10, 3)list1 = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]t.column(1).setValues(list1, 0, 9) # fill cells from 1st to 10thlist2 = [1.1, 2.2, 3.3, 4.4, 5.5, 6.6, 7.7]t.column(2).setValues(list2)list3 = [’a’, ’b’, ’c’, ’d’, "test"]t.column(3).setValues(list3, 1) # fill cells starting with 2nd row

QtiPlot stores column cell values either as floating point numerical values (doubles) or as text strings, depending on the columntype. If the column type is Table.Date or Table.Time QtiPlot converts internaly the numerical values to a QDateTime objectusing the Table.dateTime() function and displays them using the format string specified for the column. QtiPlot alsoprovides two methods that allow to perform the reverse conversion from a QDateTime or QTime object to a double floating pointnumerical value:

val1 = Table.fromDateTime(QDateTime.currentDateTime())val2 = Table.fromTime(QTime.currentTime())print val1print val2

The following script shows how you can fill a table column with date values:

t = newTable("test", 10, 2)c = t.column(1)c.setName("Date")c.setDateFormat("dd/MM/yyyy")

date = QDateTime.currentDateTime()for i in range(0, c.size()):

c.setValue(i, Table.fromDateTime(date.addDays(i)))

You can delete the content of a single cell or a range of cells using the functions bellow. Please note that after these operationsyou need to refresh the table view in order to be able to observe the changes:

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c.clearCell(1) # clear 2nd cellc.clear(0, 9) # clear range from 1st to 10th cellc.deleteCells(0, 9) # delete/remove range from 1st to 10th cellc.updateView()

For all column operations that involve a cell range if you don’t specify the index of th start row it is by default considered to bezero and if you omit the end row index (or you set it to -1) it is considered to be index of the last/bottom cell:

c.clear(10) # keeps the first 10 cells from top and clears the rest# it is equivalent to:c.clear(10, -1)c.clear() # clears the whole columnc.updateView()

The following functions provide automatic filling of a column with data values:

c.setRowValues(0, 7) # fill cell range with row indicesc.setRandomValues(0, 9) # fill cell range with random valuesc.setNormalRandomValues(0, -1, 1.0) # fill column with a Gaussian distribution with ←↩

standard deviation sigma = 1.0

It is possible to normalize a column to 1 or to sort its values in ascending or descending order:

c.normalize()c.sort() # sort column in ascending orderc.sort(Qt.DescendingOrder) # sort column in descending order

Finally, it is worth mentioning that you can copy a column (with or without its cell values) from one table to another:

t1 = newTable("test", 10, 3)t2 = table("Table1")c1 = t1.column(1)c1.copy(t2.column(1))c2 = t1.column(2)c2.copy(t2.column(2), False) # don’t copy data valuesc3 = t1.column(3)c3.copyData(t2.column(3)) # copy only the data values

7.2.8.2 Statistics on columns

There are a number of predefined statistical functions that can be used for columns having a numerical (not Text) type:

c.rms(0, 9) # returns the root mean square, also known as the quadratic meanc.sd(0, 10) # returns the standard deviation of a cell rangec.sum(0, 10) # returns the sum of all cells in the rangec.avg(0, 20) # returns the average of a cell rangec.avg() # returns the average of the whole columnc.minValue(0, 9) # returns the minimum value in a cell rangec.minValue() # returns the minimum value in columnc.maxValue(0, 100) # returns the maximum value in a cell range

7.2.8.3 Data searching

It is possible to search for a text string in a column. The search operation returns the row index of the first occurence of theresearched string. If the text string can not be found the function returns -1. Please note that by default the search operation iscase insensitive and wildcard characters are allowed.

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row = c.find("qti")print rowrow = c.find("Qti", QTextDocument.FindCaseSensitively) # case sensitive searchprint rowrow = c.find("Tuesday", QTextDocument.FindWholeWords) # find whole wordsprint row

7.2.8.4 Data mask

It is possible to mask a data cell or a range of cells in a column using:

c.mask(1, 10)c.updateView()print c.isMasked(1) # returns Trueprint c.hasMaskedCells(11, -1) # returns False

c.swapMask() # set a complementary maskc.updateView()

7.2.8.5 Import ASCII files

The function importASCII can be used to import values from an ASCII file filePath, using sep as separator character,ignoring ignoreLines lines at the beginning of the file and all lines starting with a comment string. Please note that thedefault values for the arguments of this function are given after the equality sign.

t.importASCII(filePath, sep="\t", ignoreLines=0, renameCols=False, stripSpaces=True, ←↩simplifySpace=False, importComments=False, comment="#", readOnly=False, importAs=Table. ←↩Overwrite, locale=QLocale(), endLine=0, maxRows=-1)

The names of the function arguments should be self explaining. For example, if the renameCols argument is given the valueTrue, QtiPlot will try to rename the table columns using the text strings from the first line in the imported file. Same for theimportComments argument, but in this case the second imported line is used to set the comments for the table columns.

If the simplifySpace argument is given the value True all whitespace is removed from the start and the end of each line of thefile and each sequence of internal whitespace is replaced with a single space. This can of course affect the number of importedcolumns if the column separator sep contains whitespace characters.

As you see from the above list of import options, you have the possibility to set the new columns as read-only. This will preventthe imported data from being modified. You have the possibility to remove this protection at any time, by using:

t.setReadOnlyColumn(col, False)

The importAs argument can have the following values:

0. Table.NewColumns: data values are added as new columns.

1. Table.NewRows: data values are added as new rows.

2. Table.Overwrite: all existing values are overwritten (default value).

If the number format in the imported ASCII file does not match the currently used decimal separators convention, you can specifythe correct format via the locale argument, like in the example bellow:

t.importASCII("test.txt", ’;’, 5, True, False, False, True, "", False, Table.Overwrite, ←↩QLocale(QLocale.German))

The endLine argument specifies the end line character convention used in the ascii file. Possible values are: 0 for line feed (LF),which is the default value, 1 for carriage return + line feed (CRLF) and 2 for carriage return only (usually on Mac computers).

The last parameter maxRows allows you to specify a maximum number of imported lines. Negative values mean that all datalines should be imported.

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7.2.8.6 Importing Excel sheets

It is possible to import a sheet from an Excel .xls file file to a table, using:

t = importExcel(file, sheet)

Please note that the integer variable sheet starts at 0 and must be lower than the number of sheets in the Excel workbook. Ifthe sheet index is not specified, all non-empty sheets in the Excel workbook are imported into separate tables and a reference tothe table containing the data from the last sheet is returned.

7.2.8.7 Importing ODF spreadsheets

It is possible to import a sheet from an ODF spreadsheet .ods file to a table, using:

t = importOdfSpreadsheet(file, sheet)

Please note that the integer variable sheet starts at 0 and must be lower than the number of sheets in the file. If the sheet indexis not specified, all non-empty sheets in the spreadsheet are imported into separate tables and a reference to the table containingthe data from the last sheet is returned.

7.2.8.8 Export Tables

You can export values from a table to an ASCII file, using sep as separator character. The ColumnLabels option allowsyou to export or ignore the column labels, ColumnComments does the same for the comments displayed in the table headerand the SelectionOnly option makes possible to export only the selected cells of the table.

t.exportASCII(file,sep="\t",ColumnLabels=False,ColumnComments=False,SelectionOnly=False)

Other settings that you can modify are the text displayed as a comment in the header of a column...

t.setComment(col, newComment)

... or the expression used to calculate the column values. Please beware that changing the command doesn’t automatically updatethe values of the column; you have to call recalculate explicitly. Calling it with just the column as argument will recalculateevery row. Forcing muParser can speed things up.

t.setCommand(col, newExpression)t.recalculate(col, startRow=1, endRow=-1, forceMuParser=False, notifyChanges=True)

You can also modify the width of a column (in pixels) or hide/show table columns:

t.setColumnWidth(col, width)t.hideColumn(col, True)

If one or several table columns are hidden you can make them visible again using:

t.showAllColumns()

You can ensure the visibility of a cell with:

t.scrollToCell(col, row)

After having changed some table values from a script, you will likely want to update dependent Graphs:

t.notifyChanges()

As a simple example, let’s set some column values without using the dialog.

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t = table("table1")for i in range(1, t.numRows()+1):

t.setCell(1, i, i**2)t.notifyChanges()

While the above is easy to understand, there is a faster and more pythonic way of doing the same:

t = table("table1")t.setColData(1, [i*i for i in range(len(t))])t.notifyChanges()

You can check if a column or row of a table is selected by using the following functions:

t.isColSelected(col)t.isRowSelected(row)

7.2.8.9 R interface

If RPy2 is available, the default initialization file sets up the helper functions qti.Table.toRDataFrame and qti.app.newTableFromRDataFrameto convert back and forth between R data frames and QtiPlot tables. Here is a little example of an R session...

df <- read.table("/some/path/data.csv", header=TRUE)m <- mean(df)v <- var(df)source("/some/path/my_func.r")new_df <- my_func(df, foo=bar)

... and now the same from within QtiPlot:

df = table("Table1").toRDataFrame()print R.mean(df), R.var(df)R.source("/some/path/my_func.r")new_df = R.my_func(df, foo=bar)newTableFromRDataFrame(new_df, "my result table")

7.2.9 Working with Matrices

Matrix objects have a dual view mode: either as images or as data tables. Assuming that you have assigned some matrix to thevariable m, you can change its display mode via the following function:

m.setViewType(Matrix.TableView)m.setViewType(Matrix.ImageView)

If a matrix is viewed as an image, you have the choice to display it either as gray scale or using a predefined color map:

m.setGrayScale()m.setRainbowColorMap()m.setDefaultColorMap() # default color map defined via the 3D plots tab of the preferences ←↩

dialog

You can also define custom color maps:

map = LinearColorMap(QtCore.Qt.yellow, QtCore.Qt.blue)map.setMode(LinearColorMap.FixedColors) # default mode is LinearColorMap.ScaledColorsmap.addColorStop(0.2, QtCore.Qt.magenta)map.addColorStop(0.7, QtCore.Qt.cyan)m.setColorMap(map)

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You have direct access to the color map used for a matrix via the following functions:

map = m.colorMap()col1 = map.color1()print col1.green()col2 = map.color2()print col2.blue()

Accessing cell values is very similar to Table, but since Matrix doesn’t use column logic, row arguments are specified beforecolumns and obviously you can’t use column name.

m.cell(row, col)m.setCell(row, col, value)m.text(row, col)m.setText(row, col, string)

An alternative solution to assign values to a Matrix, would be to define a formula and to calculate the values using this formula,like in the following example:

m.setFormula("x*y*sin(x*y)")m.calculate()

You can also specify a column/row range in the calculate() function, like this:

m.calculate(startRow, endRow, startColumn, endColumn)

Before setting the values in a matrix you might want to define the numeric precision, that is the number of significant digits usedfor the computations:

m.setNumericPrecision(prec)

You can change the dimensions of a matrix:

m.setDimensions(rows, columns)m.setNumRows(rows)m.setNumCols(columns)

Also, like with tables, you can access the number of rows/columns in a matrix:

rows = m.numRows()columns = m.numCols()

If QtiPlot has been built with support for ALGLIB, you can also change the dimensions of a matrix by resampling it, usingbilinear or bicubic interpolation:

m.resample(rows, cols)# bilinear interpolation by defaultm.resample(rows, cols, 1) # bicubic interpolation

If ALGLIB is available you can also smooth the matrix data using:

m.smooth()

Matrix objects allow you to define a system of x/y coordinates that will be used when plotting color/contour maps or 3D heightmaps. You can manipulate these coordinates using the following functions:

xs = m.xStart()xe = m.xEnd()ys = m.yStart()ye = m.yEnd()m.setCoordinates(xs + 2.5, xe, ys - 1, ye + 1)

You can also define labels, units and comments for the X, Y or Z axis that can be used in plots:

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m.setXLabel("Width")print m.xLabel()m.setXUnit("cm")print m.xUnit()m.setXComment("X axis comment")print m.xComment()

m.setYLabel("Height")print m.yLabel()m.setYUnit("mm")print m.yUnit()m.setYComment("Y axis comment")print m.yComment()

m.setZLabel("Intensity")print m.zLabel()m.setZUnit("a.u.")print m.zUnit()m.setZComment("Z axis comment")print m.zComment()

The horizontal and vertical headers of a matrix can display either the x/y coordinates or the column/row indexes:

m.setHeaderViewType(Matrix.ColumnRow)m.setHeaderViewType(Matrix.XY)

There are several built-in transformations that you can apply to a matrix object. You can transpose or invert a matrix and calculateits determinant, provided, of course, that the conditions on the matrix dimensions, required by these operations, are matched:

m.transpose()m.invert()d = m.determinant()

Some other operations, very useful when working with images, like 90 degrees rotations and mirroring, can also be performed.By default rotations are performed clockwise. For a counterclockwise rotation you must set the clockwise parameter toFalse.

m.flipVertically()m.flipHorizontally()m.rotate90(clockwise = True)

It is possible to perform a Fast Fourier Transform on a matrix:

m.fft() # forward FFTm.fft(True) # inverse FFT

It is also possible to apply a FFT filter to a matrix:

m.fftFilter(FFTFilter.LowPass, 0.5)m.fftFilter(FFTFilter.HighPass, 0.5)m.fftFilter(FFTFilter.BandPass, 0.5, 1.5)m.fftFilter(FFTFilter.BandBlock, 0.75, 0.9)

Please note that sometimes, after a change in the matrix settings, you need to use the following function in order to update thedisplay:

m.resetView()

Also, it’s worth knowing that you can easily import image files to matrices, that can be used afterwards for plotting (see the nextsection for more details about 2D plots):

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m1 = importImage("C:/poze/adi/PIC00074.jpg")m2 = newMatrix()m2.importImage("C:/poze/adi/PIC00075.jpg")

The algorithm used to import the image returns a gray value between 0 and 255 from the (r, g, b) triplet corresponding to eachpixel. The gray value is calculated using the formula: (r * 11 + g * 16 + b * 5)/32

For custom image analysis operations, you can get a copy of the matrix image view, as a QImage object, via:

image = m.image()

You can export matrices to all raster image formats supported by Qt or to any of the following vectorial image format: EPS, PS,PDF or SVG using:

m.export(fileName)

This is a shortcut function which uses some default parameters in order to generate the output image. If you need more controlover the export parameters you must use one of the following functions:

m1.exportRasterImage(fileName, quality = 100, dpi = 0, compression = 0)m2.exportVector(fileName, color = True)

where the quality parameter influences the size of the output file. The higher this value (maximum is 100), the higher thequality of the image, but the larger the size of the resulting files. The dpi parameter represents the export resolution in pixelsper inch (the default is screen resolution). The compression parameter can be 0 (no compression) or 1 (LZW) and is onlyeffectif for .tif/.tiff images. It is neglected for all other raster image formats.

You can also import an ASCII data file, using sep as separator characters, ignoring ignore lines at the head of the file andall lines starting with a comment string:

m.importASCII(file, sep="\t", ignore=0, stripSpaces=True, simplifySpace=False, comment="#",importAs=Matrix.Overwrite, locale=QLocale(), endLine=0, maxRows=-1)

The importAs flag can have the following values:

0. Matrix.NewColumns: data values are added as new columns.

1. Matrix.NewRows: data values are added as new rows.

2. Matrix.Overwrite: all existing values are overwritten (default value).

The locale parameter can be used to specify the convention for decimal separators used in your ASCII file.

The endLine flag specifies the end line character convention used in the ascii file. Possible values are: 0 for line feed (LF),which is the default value, 1 for carriage return + line feed (CRLF) and 2 for carriage return only (usually on Mac computers).

The last parameter maxRows allows you to specify a maximum number of imported lines. Negative values mean that all datalines must be imported.

Also, you can export values from a matrix to an ASCII file, using sep as separator characters. The SelectionOnly optionmakes possible to export only the selected cells of the matrix.

m.exportASCII(file, sep="\t", SelectionOnly=False)

7.2.10 Table/Matrix conversion

If you need to get data from a table, in order to use it in a matrix (or vice-versa), you can avoid time consuming copy/pasteoperations and speed up the whole process by simply converting the table into a matrix:

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m = tableToMatrix(table("Table1"))t = matrixToTable(m)

For the production of contour or surface plots, you can convert a regular XYZ data table ("regular" meaning that cells in the Xand Y columns of the table define a regular 2D grid) into a matrix. A tolerance of 15% is used for the X and Y positions whenparsing the 2D grid.

m1 = table("Table1").convertToMatrixRegularXYZ("Data")

In the example above "Data" is the name of the Z column. You can also specify the Z column by its number and choose a limitedcell range for the conversion like in the example bellow where 0 is the index of the start row and 15 the index of the end row. Ifno cell range is specified the whole column is used for the conversion.

m2 = table("Table1").convertToMatrixRegularXYZ(2, 0, 15)

You can also convert a random XYZ data table into a matrix ("random" meaning that cells in the X and Y columns of the tabledo not define a regular 2D grid). In the example bellow "Data" is the name of the Z column, 0 is the number of the start rowand 100 is the index of the end row. The resulting matrix will be 400 rows by 500 columns. The last parameter (the radius) isused by the modified Shepard interpolation algorithm to select data points: only the closest 3D nodes whithin the user-specifiedradius will be used.

m1 = table("Table1").convertToMatrixRandomXYZ("Data", 0, 100, 400, 500, 2.5)

The last five arguments of this method are optional and have "reasonable" default values. You only need to specify the name orthe number of the Z column like in the examples bellow:

t = table("Table1")m1 = t.convertToMatrixRandomXYZ("Data")m2 = t.convertToMatrixRandomXYZ(2)

7.2.11 Stem Plots

A stem-plot (or stem-and-leaf plot), in statistics, is a device for presenting quantitative data in a graphical format, similar to ahistogram, to assist in visualizing the shape of a distribution. A basic stem-plot contains two columns separated by a verticalline. The left column contains the stems and the right column contains the leaves. See Wikipedia for more details.

QtiPlot provides a text representation of a stem-plot. The following function returns a string of characters representing thestatistical analysis of the data:

text = stemPlot(Table *t, columnName, power = 1001, startRow = 0, endRow = -1)

where the power variable is used to specify the stem unit as a power of 10. If this parameter is greater than 1000 (the defaultbehavior), than QtiPlot will try to guess the stem unit from the input data and will pop-up a dialog asking you to confirm theautomatically detected stem unit.

Once you have created the string representation of the stem-plot, you can display it in any text editor you like: in a note withinthe project or even in the results log:

resultsLog().append(stemPlot(table("Table1"), "Table1_2", 1, 2, 15))

7.2.12 2D Plots

Graph windows usually display several plot layers. It is possible to get a reference to the active layer:

l = g.activeLayer()

but you can also select a layer by its number:

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l = g.layer(num)

The default background color of a graph is white, but it is possible to fill it with a different background color or with a lineargradient brush, using:

g = graph("Graph1")g.setBackgroundColor(QtGui.QColor(Qt.gray))g.setGradientBrush(2, 100) # one color gradientg.setGradientBrush(3, QtGui.QColor(Qt.blue)) # two colors gradient

7.2.12.1 The plot title

l.setTitle("My beautiful plot")l.setTitleFont(QtGui.QFont("Arial", 12))l.setTitleColor(Qt.red)l.setTitleAlignment(QtCore.Qt.AlignLeft)

The alignment parameter can be any combination of the Qt alignment flags (see the Qt documentation for more details).

If you want you can remove the plot title using:

l.removeTitle()

You can access the plot title properties using the following getter functions:

print l.titleString()font = l.titleFont()color = l.titleColor()alignment = l.titleAlignment()

Here’s how you can add greek symbols in the plot title or in any other text in the plot layer: axis labels, legends:

l.setTitle("normal text <font face=\"Symbol\">greek text</font>")

Using the font specifications, you can also change the color of some parts of the title only:

l=newGraph().activeLayer()l.setTitle("<font color = red>red</font> <font color = yellow>yellow</font> <font color = ←↩

blue>blue</font>")

7.2.12.2 Customizing the axes

Layer axes can be shown/hidden using the following function:

l.enableAxis(int axis, on = True)

where axis can be any integer value between 0 and 3 or the equivalent reserved word:

0. Layer.Left

1. Layer.Right

2. Layer.Bottom

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3. Layer.Top

The X-Y axes of a plot layer can be exchanged using the following function:

l.exchangeXYAxes()

If an axis is enabled, you can fully customize it via a Python script. For example you can set its title:

l.setAxisTitle(Layer.Bottom, "time (ms)")l.setAxisTitleFont(Layer.Bottom, QtGui.QFont("Arial", 11))l.setAxisTitleColor(Layer.Bottom, Qt.blue)l.setAxisTitleAlignment(Layer.Bottom, Qt.AlignRight)l.setAxisTitleDistance(Layer.Bottom, 20)

its color and the font used for the tick labels:

l.setAxisColor(Layer.Left, Qt.green)l.setAxisFont(Layer.Left, QtGui.QFont("Arial", 10))

You can access the axis title properties using the following getter functions:

print l.axisTitleString(Layer.Bottom)font = l.axisTitleFont(Layer.Top)color = l.axisTitleColor(Layer.Right)alignment = l.axisTitleAlignment(Layer.Left)dist = l.axisTitleDistance(Layer.Left)

The other axis properties can be retrieved using the following methods:

font = l.axisFont(Layer.Top)color = l.axisColor(Layer.Right)formula = l.axisFormula(Layer.Bottom)

The tick labels of an axis can be enabled or disabled, you can set their color and their rotation angle:

l.enableAxisLabels(axis, on = True)l.setAxisLabelsColor(Layer.Bottom, Qt.red)l.setAxisLabelRotation(Layer.Bottom, 90)

angle can be any integer value between -90 and 90 degrees.

The properties of the axis labels can be retrieved using:

color = l.axisLabelsColor(Layer.Left)angle = l.axisLabelsRotation(Layer.Left)

The numerical format of the labels can be set using:

l.setAxisNumericFormat(axis, format, precision = 6, formula)

where format can have the following values:

0. Automatic: the most compact numeric representation is chosen

1. Decimal: numbers are displayed in floating point form

2. Scientific: numbers are displayed using the exponential notation

3. Superscripts: like Scientific, but the exponential part is displayed as a power of 10

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precision is the number of significant digits and formula is a mathematical expression that can be used to link oppositescales. It’s argument must be x for horizontal axes and y for vertical axes. For example, assuming that the bottom axis displaysa range of wavelengths in nanometers and that the top axis represents the equivalent energies in eV, with the help of the codebelow all the wavelengths will be automatically converted to electron-volts and the result will be displayed in floating point formwith two significant digits after the decimal dot sign:

l.setAxisNumericFormat(Layer.Top, 1, 2, "1239.8419/x")print l.axisFormula(Layer.Top)

The axis ticks can be customized via the following functions:

l.setTicksLength(minLength, majLength)print l.minorTickLength()print l.majorTickLength()

l.setMajorTicksType(axis, majTicksType)l.setMinorTicksType(axis, minTicksType)l.setAxisTicksLength(axis, majTicksType, minTicksType, minLength, majLength)

where the majTicksType and minTicksType parameters specify the desired orientation for the major and minor ticks,respectively:

0. Layer.NoTicks

1. Layer.Out: outward orientation for ticks, with respect to the plot canvas

2. Layer.InOut: both inward and outward ticks

3. Layer.In: inward ticks

minLength specifies the length of the minor ticks, in pixels and majLength the length of the major ticks.

You can also customize the scales of the different axes using:

l.setScale(int axis, double start, double end, double step=0.0, int majorTicks=5, int ←↩minorTicks=5, int type=0, bool inverted=False)

where type specifies the desired scale type:

0. Layer.Linear

1. Layer.Log10

2. Layer.Ln

3. Layer.Log2

4. Layer.Reciprocal

5. Layer.Probability

6. Layer.Logit

and step defines the size of the interval between the major scale ticks. If not specified (default value is 0.0), the step size iscalculated automatically. The other flags should be self-explanatory.

It is possible to access the scale type of an axis via the following "getter" function:

print l.axisScaleType(Layer.Bottom)

The type of an axis (Numerical, Day, Month, Date/Time, etc...) can be obtained using:

print l.axisType(Layer.Bottom)

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It is possible to get information about the scale division of an axis via the following functions:

div = graph("Graph1").activeLayer().axisScaleDiv(Layer.Left)print div.lowerBound()print div.upperBound()print div.range()

Defining a scale range for an axis doesn’t automatically disable autoscaling. This means that if a curve is added or removed fromthe layer, the axes will still automatically adapt to the new data interval. This can be avoided by disabling the autoscaling mode,thus making sure that your scale settings will always be taken into account:

l.enableAutoscaling(False)l.setSynchronizedScaleDivisions(False)

If you want to rescale the plot layer so that all the data points are visible, you can use the following utility function:

l.setAutoScale()

The same setScale function above, with a longer list of arguments, can be used to define an axis break region:

l.setScale(axis, start, end, step=0.0, majorTicks=5, minorTicks=5, type=0, inverted=False,left=-DBL_MAX, right=DBL_MAX, breakPosition=50, stepBeforeBreak=0.0, stepAfterBreak=0.0,minTicksBeforeBreak=4, minTicksAfterBreak=4, log10AfterBreak=False, breakWidth=4, ←↩

breakDecoration=True)

where left specifies the left limit of the break region, right the right limit, breakPosition is the position of the breakexpressed as a percentage of the axis length and breakWidth is the width of the break region in pixels. The names of the otherparameters should be self-explanatory.

You can also invert the scale of an axis using the following direct method:

l.invertScale(Layer.Bottom)print l.hasInvertedScale(Layer.Bottom)

Finally, you can specify the width of all axes and enable/disable the drawing of their backbone line, using:

l.setAxesLinewidth(2)l.drawAxesBackbones(True)

7.2.12.3 The canvas

You can display a rectangular frame around the drawing area of the plot (the canvas) and fill it with a background color, a lineargradient brush or with an image, using:

l.setCanvasFrame(2, QtGui.QColor("red"))l.setCanvasColor(QtGui.QColor("lightGrey"))l.setCanvasGradientBrush(3, QtGui.QColor(Qt.blue))l.setCanvasBackgroundImage("C:/qtiplot/qtiplot/qtiplot_logo.png")

As you have seen above it is possible to fill the canvas with a linear gradient brush. There are sixteen predefined gradient types.The first argument of the "setter" functions is the gradient type and must be a value between 0 and 15. The second argumentcan be either a color or an integer value. If the second argument is a color the linear gradient interpolates between the canvasbackground color and the specified color. If you specify an integer value (the lightness) the second color of the linear gradientis a lighter/darker color with respect to the background color. The lightness must be an integer value between 0 (black) and 100(white).

l.setCanvasGradientBrush(3, QtGui.QColor(Qt.blue))l.setCanvasGradientBrush(3, 90)

The following access methods are available for the canvas background image:

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pic = l.backgroundPixmap() # QPixmappath = l.canvasBackgroundFileName()

Drawing the canvas frame and disabling the axes backbone lines is the only possible solution for the issue of axes not touchingthemselves at their ends.

7.2.12.4 The layer frame

You can display a rectangular frame around the whole layer and fill it with a background color or with a linear gradient brush,using:

l.setFrame(2, QtGui.QColor("blue"))l.setBackgroundColor(QtGui.QColor("grey"))l.setGradientBrush(3, QtGui.QColor(Qt.blue))

The default spacing between the layer frame and the other layer elements (axes, title) can be changed via:

l.setMargin(10)

7.2.12.5 Customizing the grid

You can display or hide the grid associated to a layer axis or the whole grid using the functions bellow:

l.showGrid()l.hideGrid()l.showGrid(axis)l.hideGrid(axis)l.setGridOnTop(on = True, update = True) # draw grid on top of data

This will display the grid with the default color, width and pen style settings. If you need to change these settings, as well as toenable/disable certain grid lines, you can use the following functions:

grid = l.grid()grid.setMajPenX(QtGui.QPen(QtCore.Qt.red, 1))grid.setMinPenX(QtGui.QPen(QtCore.Qt.yellow, 1, QtCore.Qt.DotLine))grid.setMajPenY(QtGui.QPen(QtCore.Qt.green, 1))grid.setMinPenY(QtGui.QPen(QtCore.Qt.blue, 1, QtCore.Qt.DashDotLine))grid.enableXMaj()grid.enableXMin()grid.enableYMaj(False)grid.enableYMin(False)grid.enableZeroLineX(True)grid.enableZeroLineY(False)grid.setXZeroLinePen(QtGui.QPen(QtCore.Qt.black, 2))grid.setYZeroLinePen(QtGui.QPen(QtCore.Qt.black, 2))l.replot()

All the grid functions containing an X refer to the vertical grid lines, whereas the Y letter indicates the horizontal ones. Also, theMaj word refers to the main grid lines and Min to the secondary grid.

7.2.12.6 The plot legend

Plot legends can be accessed as shown in the script bellow. You should be aware of the fact that not all plot layers have legends.If the legend object was deleted, the instance returned by the legend() function might be null:

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layer = graph("Graph1").activeLayer()legend = layer.legend()if legend: # the current legend might be NULL

legend.setOrigin(100, 80)else:

print "This layer doesn’t have a legend!"

You can add a new legend to a plot using:

legend = l.newLegend()#orlegend = l.newLegend("enter your text here")

Plot legends are special text objects which are updated each time you add or remove a curve from the layer. They have a specialauto-update flag which is enabled by default. The following function returns True for a legend object:

legend.isAutoUpdateEnabled()

You can disable/enable the auto-update behavior of a legend/text object using:

legend.setAutoUpdate(False/True)

You can add common texts like this:

text = l.addText(legend)text.setOrigin(legend.x(), legend.y()+50)

Please notice that the addText function returns a different reference to the new text object. You can use this new reference lateron in order to remove the text:

l.remove(text)

Once you have created a legend/text, it’s very easy to customize it. If you want to modify the text you can use:

legend.setText("Enter your text here")

All other properties of the legend: rotation angle, text color, background color, frame style, font and position of the top-left cornercan be modified via the following functions:

legend.setAngle(90)legend.setTextColor(QtGui.QColor("red"))legend.setBackgroundColor(QtGui.QColor("yellow"))legend.setFrameStyle(Frame.Shadow)legend.setFrameColor(QtCore.Qt.red)legend.setFrameWidth(3)legend.setFrameLineStyle(QtCore.Qt.DotLine)legend.setFont(QtGui.QFont("Arial", 14, QtGui.QFont.Bold, True))# set top-left position using scale coordinates:legend.setOriginCoord(200.5, 600.32)# or set top-left position using pixel coordinates:legend.setOrigin(5, 10)legend.repaint()

Some of the properties of the legend can be accessed via the following "getter" functions:

angle = legend.angle()color = legend.textColor()font = legend.font()x = legend.xValue()# top position in scale coordinatesy = legend.yValue()# left position in scale coordinates

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Other frame styles available for legends are: Legend.Line, which draws a rectangle around the text and Legend.None (noframe at all). There is also a function allowing you to add an automatically built time stamp:

timeStamp = l.addTimeStamp()

Finally, it is possible to iterate over the list of all texts/legends in a plot layer:

layer = graph("Graph1").activeLayer()for legend in layer.textsList():

print legend.text()

7.2.12.7 Antialiasing

Antialiasing can be enabled/disabled for the drawing of the curves and other layer objects, but it is a very resources consumingfeature:

l.setAntialiasing(True, bool update = True)

7.2.12.8 Resizing layers

A layer can be resized using the methods below, where the first argument is the new width, the second is the new height and sizesare defined in pixels:

l.resize(200, 200);l.resize(QSize(w, h))

If you also need to reposition the layer, you can use the following functions, where the first two arguments specify the newposition of the top left corner of the canvas:

l.setGeometry(100, 100, 200, 200);l.setGeometry(QRect(x, y, w, h));

By default, when resizing 2D plot windows, QtiPlot adapts the sizes and aspect of the layers to the new size of the plot window.You can override this behavior and keep the aspect and size of the graph layers unchanged:

g = newGraph("test", 2, 1, 2)g.arrangeLayers()g.setScaleLayersOnResize(False)

Also, the default behavior of 2D plot layers with respect to the resizing of the graph window is to adapt the sizes of the fonts usedfor the various texts, to the new size of the plot window. You can override this behavior and keep the size of the fonts unchanged:

l.setAutoscaleFonts(False)

7.2.12.9 Resizing the drawing area

The drawing area of a layer (the canvas) can be resized using the methods below, where the first argument is the new width, thesecond is the new height and sizes are defined in pixels:

l.setCanvasSize(200, 200);l.setCanvasSize(QSize(w, h))

If you also need to reposition the canvas, you can use the following functions, where the first two arguments specify the newposition of the top left corner of the canvas:

l.setCanvasGeometry(100, 100, 200, 200);l.setCanvasGeometry(QRect(x, y, w, h));

Please keep in mind that the fonts of the layer are not rescaled when you resize the layer canvas using the above methods.

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7.2.12.10 Working with 2D curves

If you want to create a new Graph window for some data in table Table1, you can use the plot command:

t = table("Table1")g = plot(t, column, type)

column can be either the name of the column (string value) or the column index (integer value) and type specifies the desiredplot type and can be one of the following numbers or the equivalent reserved word:

0 Layer.Line

1 Layer.Scatter

2 Layer.LineSymbols

3 Layer.VerticalBars

4 Layer.Area

5 Layer.Pie

6 Layer.VerticalDropLines

7 Layer.Spline

8 Layer.HorizontalSteps

9 Layer.Histogram

10 Layer.HorizontalBars

13 Layer.Box

15 Layer.VerticalSteps

23 Layer.BSpline

24 Layer.Bezier

You can plot more than one column at once by giving a Python tuple (see the Python Tutorial) as an argument:

g1 = plot(table("Table1"), (2,4,7), 2)g2 = plot(table("Table1"), ("Table1_2","Table1_3"), Layer.LineSymbols)

There are some curve types that specifically request at least two Y columns, the first column in the tuple being used as baseline:

26 Layer.FloatingColumn

27 Layer.FloatingBar

29 Layer.FillArea

l.addCurves(table("Table1"), (2, 3), Layer.FloatingColumn)l.addCurves(table("Table1"), (2, 3), Layer.FillArea)

Some predefined plot types that can be used to stack the plot curves by adding an offset to their Y values:

21 Layer.StackBar

22 Layer.StackColumn

25 Layer.StackArea

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28 Layer.StackLine

30 Layer.StackBarPercent

31 Layer.StackColumnPercent

32 Layer.StackAreaPercent

l.addCurves(table("Table1"), (2, 3), Layer.StackColumn)

The stack offset can be customized using one of the following modes:

0 Layer.NoOffset

1 Layer.CumulativeOffset

2 Layer.ConstantOffset

3 Layer.AutoOffset

4 Layer.IndividualOffset

l.addCurves(table("Table1"), (2, 3), Layer.StackLine)l.stackCurves(Layer.AutoOffset, 0.1)

In the example above the relative gap between the plot curves was set to 10% (0.1). The offset can be set to a constant value ifthe stack mode is set to Layer.ConstantOffset:

l.addCurves(table("Table1"), (2, 3), Layer.Line)l.stackCurves(Layer.ConstantOffset, 1000)

or you can specify a different offset for each plot curve:

l.addCurves(table("Book1"), ("B", "C"), Layer.Area)l.stackCurves(Layer.IndividualOffset)c = l.dataCurve(1)c.setOffset(2, 500)print c.xOffset(), c.yOffset()

In the case of the following plot types: StackAreaPercent, StackBarPercent and StackColumnPercent the stackmode is set to CumulativeOffset and the data values are percent normalized. A special hasPercentNormalizedStack flag is set for these plot types:

print l.hasPercentNormalizedStack()

which of course can be disabled:

l.setPercentNormalizedStack(False)l.stackCurves(Layer.CumulativeOffset)

You can add or remove curves to or from a plot layer:

l.insertCurve(table, Ycolumn, type=Layer.Scatter, int startRow = 0, int endRow = -1)# ←↩returns a reference to the inserted curve

l.insertCurve(table, Xcolumn, Ycolumn, type=Layer.Scatter, int startRow = 0, int endRow = ←↩-1)# returns a reference to the inserted curve

l.addCurve(table, column, type=Layer.Line, lineWidth = 1, symbolSize = 3, startRow = 0, ←↩endRow = -1)# returns True on success

l.addCurves(table, (2,4), type=Layer.Line, lineWidth = 1, symbolSize = 3, startRow = 0, ←↩endRow = -1)# returns True on success

l.removeCurve(curveName)l.removeCurve(curveIndex)l.removeCurve(curveReference)l.deleteFitCurves()

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It is possible to copy all the curves from a source plot layer lSrc to a destination layer lDest:

lSrc = graph("Graph1").activeLayer()lDest = newGraph().activeLayer()lDest.copyCurves(lSrc)

Of course, you can also clone an entire plot layer:

lDest.copy(lSrc)

It is possible to change the order of the curves inserted in a layer using the following functions:

l.changeCurveIndex(int oldIndex, int newIndex)l.reverseCurveOrder()

You can also change the Z order of the curves:

l.switchCurveZ(int oldIndex, int newIndex);l.reverseCurveZOrder()

If the table column used to create a plot curve has empty cells, you can choose whether the curve line is drawn connected acrossthe missing data or not. This behavior can be specified using:

l.showMissingDataGap(on = True, replot = True)

Sometimes, when performing data analysis, one might need the curve title. It is possible to obtain it using the method below:

title = l.curveTitle(curveIndex)

It is possible to get a reference to a curve on the layer l using it’s index or it’s title, like shown below:

c = l.curve(curveIndex)c = l.curve(curveTitle)dc = l.dataCurve(curveIndex)

Please, keep in mind the fact that the above methods might return an invalid reference if the curve with the specified index/title isnot a PlotCurve or a DataCurve object, respectively. For example, an analytical function curve is a PlotCurve but not aDataCurve and spectrograms are a completely different type of plot items which are neither PlotCurves nor DataCurves.Once you have a reference to a PlotCurve c it is possible to get its type and title using the methods bellow:

c = graph("Graph1").activeLayer().curve(0)print c.type()print c.name()

Use the following functions to change the axis attachment of a curve:

l.setCurveAxes(index, xAxis, yAxis)c.setXAxis(xAxis)c.setYAxis(yAxis)

where index is the index of the curve (starting at zero), xAxis can be either Layer.Bottom or Layer.Top and yAxiscan be either Layer.Left or Layer.Right:

l.setCurveAxes(0, Layer.Top, Layer.Right)# modify the first curve in the layerc.setXAxis(Layer.Bottom)c.setYAxis(Layer.Right)#attach curve c to the right Y axis

The following functions give information about the axes to which a curve is attached:

print c.xAxis()print c.yAxis()

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In case you need the number of curves on a layer, you can get it with

l.numCurves()

It is possible to change the number of symbols to be displayed for a curve using the function below. This option can be veryusefull for very large data sets:

c.setSkipSymbolsCount(3)print c.skipSymbolsCount()

Once you have added a curve to a plot layer you can fully customize it’s appearance:

l = newGraph().activeLayer()l.setAntialiasing()c = l.insertCurve(table("Table1"), "Table1_2", Layer.LineSymbols)c.setPen(QPen(Qt.red, 3))c.setBrush(QBrush(Qt.darkYellow))c.setFillAreaColor(Qt.green)c.setGradientBrush(3, QColor(Qt.blue))c.setSymbol(PlotSymbol(PlotSymbol.Hexagon,QBrush(Qt.cyan),QPen(Qt.blue,1.5),QSize(15,15)))c.setLineStyle(PlotCurve.AkimaSpline)

A curve can be customized using one of the following line styles:

0 PlotCurve.NoCurve: the line is not drawn

1 PlotCurve.Lines: a simple line

2 PlotCurve.Sticks: vertical drop lines

3 PlotCurve.HorizontalSteps: a horizontal stepped line

4 PlotCurve.Dots: the line is drawn as a series of dots

5 PlotCurve.Spline: a normal spline

6 PlotCurve.VerticalSteps: a vertical stepped line

7 PlotCurve.BSpline:a B-spline (or basis spline)

8 PlotCurve.Bezier: Bezier spline

9 PlotCurve.AkimaSpline: the line is drawn as an Akima interpolation

An alternative way of customizing a curve in terms of color, line width and line style is by using the functions below, where thefirst argument is the curve index:

l.setCurveLineColor(0, QtGui.QColor(Qt.red))# or set color by its index in the default color list: 0=black, 1=red, 2=green,...:l.setCurveLineColor(0, 1)l.setCurveLineStyle(0, Qt.DashLine)l.setCurveLineWidth(0, 0.5) # set the linewidth to 0.5

Here’s a short script showing these functions at work:

t = newTable("test", 30, 4)for i in range(1, t.numRows()+1):

t.setCell(1, i, i)t.setCell(2, i, i)t.setCell(3, i, i+2)t.setCell(4, i, i+4)

l = qti.app.plot(t, (2,3,4), Layer.Line).activeLayer() # plot columns 2, 3 and 4

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for i in range(0, l.numCurves()):l.setCurveLineColor(i, 1 + i)l.setCurveLineWidth(i, 0.5 + i)l.setCurveLineStyle(1, 1 + i)

It is possible to define a global color policy for the plot layer using the following convenience functions:

l.setGrayScale()l.setGradientColorScale(Qt.yellow, Qt.cyan)# use colors from the default color list: 0 = black, 1 = red, 2 = green, etc...:l.setIndexedColors()

Other useful functions allowing to edit the style of all the curves in a plot layer with a single call are:

l.incrementLineStyle()l.incrementFillPattern()

If you need to change the range of data points displayed in a DataCurve you can use the following methods:

c.setRowRange(int startRow, int endRow)c.setFullRange()

Also, you can hide/show a plot curve via:

c.setVisible(bool on)

7.2.12.11 Curve baseline

When you define a filling brush for the area beneath a plot curve the baseline of the filling area is by default the line y = 0.Nevertheless you can specify a different y value to be the baseline reference:

c = newGraph().activeLayer().addFunction("sin(x)", 0, 2*pi, 100)c.setBrush(QColor(255, 0, 0, 100))c.setBaseline(0.5)print c.baseline()

You can also specify a different plot curve to act as a custom baseline:

l = newGraph().activeLayer()c1 = l.addFunction("sin(x)", 0, 2*pi, 100)c2 = l.addFunction("cos(x)", 0, 2*pi, 100)c2.setBrush(QBrush(Qt.darkYellow))c2.setBaselineCurve(c1)print c2.baselineCurve().name()

In the case of DataCurves you can also specify a data column as the custom baseline:

c.setBaselineColumn("Table1_2") # the data source of curve c is table "Table1"print c.baselineColumnName()

7.2.12.12 Curve values

In case you need information about the data stored in a plot curve, the functions bellow return Python lists containing the abscissasand the ordinates of all the data points:

abscissaList = c.xValues()ordinateList = c.yValues()

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Or you have at your disposal functions that give access to the values of the individual data points:

points = c.dataSize()for i in range (0, points):

print i, "x = ", c.x(i), "y = ", c.y(i)

You can also get information about the range (minimum and maximum values) of the data stored in a 2D plot curve:

print c.minXValue()print c.maxXValue()print c.minYValue()print c.maxYValue()

It is also possible to get references to the data table and data column objects used to create a DataCurve. Please note that thereference to the column containing the abscissas may be null for some data curves:

dc = graph("Graph1").activeLayer().dataCurve(0)t = dc.table()xCol = dc.xColumn() # abscissas columnyCol = dc.yColumn() # ordinates columnprint xCol.index(), xCol.fullName(), yCol.index(), yCol.fullName()print t.objectName()

7.2.12.13 Curve symbols

Here’s how you can customize the plot symbol used for a 2D plot curve c:

s = c.symbol()s.setSize(QtCore.QSize(7, 7))# or s.setSize(7)s.setBrush(QtGui.QBrush(Qt.darkYellow))s.setPen(QtGui.QPen(Qt.blue, 3))s.setStyle(PlotSymbol.Diamond)l.replot() # redraw the plot layer object

The symbol styles available in QtiPlot are:

-1 PlotSymbol.NoSymbol

0 PlotSymbol.Ellipse

1 PlotSymbol.Rect

2 PlotSymbol.Diamond

3 PlotSymbol.Triangle

4 PlotSymbol.DTriangle

5 PlotSymbol.UTriangle

6 PlotSymbol.LTriangle

7 PlotSymbol.RTriangle

8 PlotSymbol.Cross

9 PlotSymbol.XCross

10 PlotSymbol.HLine

11 PlotSymbol.VLine

12 PlotSymbol.Star1

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13 PlotSymbol.Star2

14 PlotSymbol.Hexagon

15 PlotSymbol.Pentagon

16 PlotSymbol.Star3

If the the shape of the symbol is an ellipse (a circle in fact), the setCircleSizeType method lets you choose how the areaof the symbols is determined from their defined size. Three options are available:

0 PlotCurve.BasedOnSquare: The area is calculated as the area of the square enclosing the circle (A = Size*Size).

1 PlotCurve.BasedOnDiameter: The diameter of the circle equals the value defined for Size (A = Pi*Size*Size/4).

2 PlotCurve.BasedOnArea: The area of the circle equals the value defined for the Size (A = Size).

g = graph("Graph1").activeLayer()c = g.curve(0)c.setCircleSizeType(PlotCurve.BasedOnArea)g.replot()

It is worth knowing that you can define a custom image as the plot symbol for a curve:

g = newGraph().activeLayer()c = g.addFunction("cos(x)", 0, 10, 20)c.setSymbol(ImageSymbol("qtiplot/manual/html/icons/help.png"))

Here’s a short script showing how to draw a custom plot symbol and assign it to a curve:

pix = QtGui.QPixmap(QtCore.QSize(11, 11))pix.fill(Qt.transparent)p = QtGui.QPainter(pix)r = QtCore.QRect(0, 0, 10, 10)p.drawEllipse(r)p.setPen(QtGui.QPen(Qt.red))p.drawLine(5, 0, 5, 10)p.drawLine(0, 5, 10, 5)p.end()

g = newGraph().activeLayer()c = g.addFunction("sin(x)", 0, 10, 20)c.setSymbol(ImageSymbol(pix))

You can also use Unicode characters as plot symbols for a curve:

g = newGraph().activeLayer()c = g.addFunction("sin(x)", 0, 10, 20)symbol = UnicodeSymbol(0x273D)symbol.setFontSize(22)symbol.setPen(Qt.red)c.setSymbol(symbol)

It is also possible to define variable sizes for the symbols of a plot curve by indexing the cell values from a table column. Thisspecial column can be specified via the setSymbolSizeColumn method. Additionally you may set a scaling factor for thesymbol size like in the small script bellow:

t = table("Table1")g = qti.app.plot(t, "Table1_2", Layer.Scatter).activeLayer()c = g.curve(0)c.setSymbolSizeColumn(t.column(3))c.setSymbolScalingFactor(15)print c.symbolSizeColumn().fullName(), c.symbolScalingFactor()

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An equivalent way of obtaining the same result as with the script above is to use the specialized function plotBubbles. Youneed to specify two Y columns as argument of this function. The first Y column in the tuple is used for the positions of the plotsymbols and the next one determines their sizes, see the example bellow:

c = newGraph().activeLayer().plotBubbles(table("Table1"), ["2", "3"])print c.symbolSizeColumn().fullName(), c.symbolScalingFactor()

It is also possible to define a default color map for the plot symbols using the values from a table column. Both the filling colorand the edge color can be customized, using the functions bellow:

g = graph("Graph1").activeLayer()c = g.curve(0)t = table("Table1")c.setSymbolEdgeColorColumn(t.column(2))c.setSymbolFillColorColumn(t.column(3))g.replot()

print c.symbolEdgeColorColumn().fullName(), c.symbolFillColorColumn().fullName()

The default color map of a plot curve can be modified like shown in the script bellow:

g = graph("Graph1").activeLayer()c = g.curve(0)map = c.colorMap()map.setColorInterval(Qt.blue, Qt.yellow)map.addColorStop(0.5, Qt.red)c.setColorMap(map)g.replot()

The convenience function setColorMapIntensityRangeFromColumn can be used in order to modify the intensity rangeof the color map. This function finds the minimum and maximum values in the specified column and confines the intensity rangebetween this interval:

g = graph("Graph1").activeLayer()c = g.curve(0)c.setColorMapIntensityRangeFromColumn(table("Table1").column(3))g.replot()

The specialized functions plotColorMappedSymbols and plotColorMappedBubbles can also be used in order to geta 2D plot curve displaying color mapped symbols. You need to specify at least two Y columns for these functions: the firstis used for the positions of the plot symbols and the second determines their color. QtiPlot finds the minimum and maximumvalues in the second Y column, creates eight evenly sized ranges of values between the minimum and maximum values, and thenassociates a color with each range of values. The color of each data point is determined by finding the color associated with thesecond Y column value in the color map.

g = newGraph().activeLayer()c = g.plotColorMappedSymbols(table("Table1"), ["2", "3"])c.symbol().setSize(10)

The plotColorMappedBubbles function also accepts a tuple of three columns: the first is used for the positions of the plotsymbols, the second determines their sizes and the third the color of their edges. This function automatically sets the filling colorof the plot symbols to white.

g = newGraph().activeLayer()c = g.plotColorMappedBubbles(table("Table1"), ["2", "3", "4"])print c.symbolScalingFactor()

Alternatively, in order to get the same graphs, you can use the addCurves function and the following curve types:

34 Layer.Bubble

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34 Layer.ColorMappedSymbols

36 Layer.ColorMappedBubbles

But instead of a direct reference to the newly created plot curve this function returns a boolean result:

g = newGraph().activeLayer()ok = g.addCurves(table("Table1"), (2, 3, 4), Layer.ColorMappedSymbols, 0, 10)print ok # prints True on success

7.2.12.14 Curve labels

It is possible to display labels for each data point in a DataCurve. The labels can be set using the method bellow:

c.setLabelsForm(DataCurve.YValues)

and may have one of the following predefined forms:

0 DataCurve.XValues

1 DataCurve.YValues

2 DataCurve.RowIndices

3 DataCurve.XYValues

You may also specify the labels using the texts in a table column:

c.setLabelsColumnName("Table1_2")

If the labels have numerical values, you can change their display format and precision:

c.setLabelsNumericFormat(2, 3)# display labels with scientific format and three significant ←↩digits

c.setLabelsNumericPrecision(2)

The available formats are:

0. Automatic: the most compact numeric representation is chosen

1. Decimal: numbers are displayed in floating point form (10.000)

2. Scientific: numbers are displayed using the exponential notation (1e4)

The position of the labels can be set using the method bellow:

c.setLabelsAlignment(DataCurve.Right)

The following predefined positions can be used:

0 DataCurve.Center

1 DataCurve.Left

2 DataCurve.Right

3 DataCurve.Above

4 DataCurve.Bellow

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If the data curve is a column/bar/histogram curve the following predefined positions should be used instead:

0 DataCurve.Center

1 DataCurve.InsideEnd

2 DataCurve.InsideBase

3 DataCurve.OutsideEnd

Other properties of the labels can be customized using the functions bellow:

c.setLabelsOffset(50, 50)c.setLabelsColor(Qt.red)c.setLabelsFont(QtGui.QFont("Arial", 14))c.setLabelsRotation(45)

You can disable the labels of a data curve using:

c.clearLabels()l.replot() # redraw the plot layer object

7.2.12.15 Curve drop shadow

It is possible to enable/disable the display of drop shadows for all curves in a plot layer at once:

g = graph("Graph1").activeLayer()# set shadow color to light gray, offset to 5 pixels and blur radius to 8g.setDropShadowProperties(Qt.lightGray, 5, 8.0)g.enableCurveDropShadows(True)

It is equally possible to enable/disable the drop shadow effect for each curve individually:

g = graph("Graph1").activeLayer()c = g.curve(0)if (c.hasDropShadow()):

c.enableDropShadow(False)g.replot()

7.2.12.16 Selecting a data range

You can activate the "Select Data Range" tool for a plot layer and select the active curve using the following method:

g = graph("Graph1").activeLayer()g.enableRangeSelectors()g.setSelectedCurve(g.curve(0))g.setActivePoint(20)g.switchActiveMarker()g.setActivePoint(90)g.replot()

If a plot curve is selected you can get the coordinates of the selected data points like shown bellow:

c = g.selectedDataCurve()ap = g.selectionActivePoint()ip = g.selectionInactivePoint()print c.x(ap), c.y(ap), c.x(ip), c.y(ip)

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If the selected plot curve is also a DataCurve, meaning that it has a valid data source table, unlike analytical function curves, youcan have access to the row indices of the selected data points from the source table, using the tableRow method, like shown inthe script bellow. Please note that if the selected curve is an analytical function curve and you call the tableRow method thiswill result in a crash.

c = g.selectedDataCurve()print c.tableRow(g.selectionActivePoint()) + 1print c.tableRow(g.selectionInactivePoint()) + 1

All 2D plot tools can be disabled using:

g.disableTools()

7.2.12.17 2D Analytical Functions

You can also add analytical function curves to a plot layer:

f = l.addFunction("x*sin(x)", 0, 3*pi, points = 100)f.setTitle("x*sin(x)")f.setPen(Qt.green)f.setBrush(QtGui.QColor(0, 255, 0, 100))

l.addParametricFunction("cos(m)", "sin(m)", 0, 2*pi, points = 100, variableName = "m")l.addPolarFunction("t", "t", 0, 2*pi, points = 100, variableName = "t")

It is possible to get a reference to an analytical function curve on the layer l using it’s index, like shown below:

f = l.functionCurve(curveIndex)

When dealing with analytical function curves, you can customize them using the following methods:

f.setRange(0, 2*pi)f.setVariable("t")f.setComment("My function")f.setFormulas("sin(t)", "cos(t)")f.setFunctionType(FunctionCurve.Polar) # or c.setFunctionType(FunctionCurve.Parametric)f.loadData(1000, xLog10Scale = False)

f.setFunctionType(FunctionCurve.Normal)f.setFormula("cos(x)")f.loadData()

If you need to access the values and names of a function’s parameters, you have at your disposal the following methods:

i = f.parametersCount() # the number of parameters in your function formulaname = f.parameterName(index) # the name of the parameter of rang index as a QStringp1 = f.parameterValue(index) # the value of the parameter of rang index as a doublep2 = f.parameterValue(name) # the value of a parameter using its name string

The abscissae range for which the function is calculated/displayed, can be obtained/modified via the methods below:

x1 = f.startRange()x2 = f.endRange()f.setRange(0.5, 15.2)

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7.2.12.18 Error Bars

Having a plot layer l, you can add error bars to a data curve c, named curveName, using the following methods:

err1 = l.addErrorBars(c, Table *t, QString errColName, int type = 1, double width = 1, int ←↩capLength = 8, color = Qt.black, throughSymbol = True, minusSide = True, plusSide = True ←↩)

err2 = l.addErrorBars(curveName, Table *t, QString errColName, int type = 1, double width = ←↩1, int capLength = 8, color = Qt.black, throughSymbol = True, minusSide = True, ←↩

plusSide = True)

Each data curve, c, can have attached a list of error bars:

errors = c.errorBarsList()

The properties of an error bar curve can be accesses, via the following methods:

err = c.errorBarsList()[0]for i in range(0, err.dataSize()):

print err.errorValue(i)

err.capLength()err.width()err.color()err.direction()err.xErrors()err.throughSymbol()err.plusSide()err.minusSide()c = err.masterCurve() # reference to the master curve to which the error bars curve is ←↩

attached.err.detachFromMasterCurve() # equivalent to c.removeErrorBars(err)

... and can be modified, via the following methods:

err.setCapLength(12)err.setWidth(3)err.setColor(Qt.red)err.setDirection(ErrorBarsCurve.Vertical)err.setXErrors(True) # equivalent to err.setDirection(ErrorBarsCurve.Horizontal)err.drawThroughSymbol(True)err.drawPlusSide(True)err.drawMinusSide(False)err.setMasterCurve(c)

You can remove all error bars attached to a curve using:

c.clearErrorBars()

7.2.12.19 Image and Contour Line Plots (Spectrograms)

As you have seen in the previous section, it is possible create 2D plots from matrices. Here’s how you can do it in practice:

m = importImage("C:/poze/adi/PIC00074.jpg")g1 = plot(m, Layer.ColorMap)g2 = plot(m, Layer.Contour)g3 = plot(m, Layer.GrayScale)

The plot functions above return a reference to the multilayer plot window. If you need a reference to the spectrogram objectitself, you can get it as shown in the example below:

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m = newMatrix("TestMatrix", 1000, 800)m.setFormula("x*y")m.calculate()g = plot(m, Layer.ColorMap)s = g.activeLayer().spectrogram(m)s.setColorBarWidth(20)

It is possible to fine tune the plots created from a matrix:

m = newMatrix("TestMatrix", 1000, 800)m.setFormula("x*y")m.calculate()

s = newGraph().activeLayer().plotSpectrogram(m, Layer.ColorMap)s.setContourLevels((20.0, 30.0, 60.0, 80.0))s.setDefaultContourPen(QtGui.QPen(Qt.yellow)) # set global pen for the contour liness.setLabelsWhiteOut(True)s.setLabelsColor(Qt.red)s.setLabelsFont(QtGui.QFont("Arial", 14))s.setLabelsRotation(45)s.showColorScale(Layer.Top)s.setColorBarWidth(20)

As you have seen earlier, you can set a global pen for the contour lines, using:

s.setDefaultContourPen(QtGui.QPen(Qt.yellow))

You can also assign a specific pen for each contour line, using the function below:

s.setContourLinePen(index, QPen)

or you can automatically set pen colors defined by the color map of the spectrogram:

s.setColorMapPen(bool on = True)

You can also use any of the following functions:

s.setMatrix(Matrix *, bool useFormula = False)s.setUseMatrixFormula(bool useFormula = True)# calculate data to be drawn using matrix ←↩

formula (if any)s.setLevelsNumber(int)s.showColorScale(int axis, bool on = True)s.setGrayScale()s.setDefaultColorMap()s.setCustomColorMap(LinearColorMap map)s.showContourLineLabels(bool show = True) # enable/disable contour line labelss.setLabelsOffset(int x, int y) # offset values for all labels in % of the text sizes.updateData()

7.2.12.20 Histograms

As you have seen in the previous section, it is possible to create 2D histograms from matrices or tables. The script bellow showsa straightforward way of plotting a histogram from a table column:

h = newGraph().activeLayer().addHistogram(table("Table1"), "Table1_2")h.setBinCount(5, 1, 30)# the number of bins is set to 5, data range is set to [1, 30]

or from a matrix:

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g = plotHistogram(matrix("Matrix1")).activeLayer()

A more complex plot type that displays a histogram together with the corresponding cumulative probabilities can be created:

g1 = plotHistogramProbabilities(table("Table1"), "Table1_2").activeLayer()g2 = plotHistogramProbabilities(matrix("Matrix1")).activeLayer()

It is also possible to get a reference to a previously created histogram and to modify it according to your needs:

g = graph("Graph1").activeLayer()h = g.histogram(0)# g is a plot containing one histogramh.setBinCount(8, 1, 30)g.replot()

Here’s a small script showing how to customize a histogram and how to get access to the statistical information in the histogram(bin positions, counts, mean, standard deviation, etc...):

m = newMatrix("TestHistogram", 1000, 800)m.setFormula("x*y")m.calculate()

g = newGraph().activeLayer()h = g.addHistogram(m)h.setBinSize(10, 1, 90) # the bin size is set to 10, data range is set to [1, 90]

# print histogram values:for i in range (0, h.dataSize()):

print ’Bin {0}: start = {1}, counts = {2}’.format(i + 1, h.x(i), h.y(i))

# print statistic information:print "Standard deviation = ", h.standardDeviation()print "Mean = ", h.mean()print "Maximum = ", h.maximum()print "Minimum = ", h.minimum()print "Number of bins = ", h.binCount()print "Bin size = ", h.binSize()

You can also enable autobinning (a default number of ten bins will be used):

h.setAutoBinning()

7.2.12.21 Box and whiskers plots

The following script shows how to create and customize a box and whiskers plot:

g = newGraph().activeLayer()g.plotBox(table("Table1"), ["2", "3", "4"])for i in range (0, g.numCurves()):

box = g.boxCurve(i)if (box):

box.setBrush(QtGui.QBrush(Qt.red, Qt.BDiagPattern))s = PlotSymbol()s.setPen(QtGui.QPen(Qt.blue, 2))s.setSize(QtCore.QSize(10, 10))box.setSymbol(s)box.setMeanStyle(PlotSymbol.Cross)box.setBoxStyle(BoxCurve.WindBox)box.setBoxWidth(80)box.setWhiskersRange(BoxCurve.SD) # standard deviation

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The following functions give access to the statistics information for the data series displayed with a box and whiskers plot:

s = box.statistics() # returns information as a stringm = box.median()q = box.quantile(f) # f must be a fraction between 0 and 1

For an exhaustive review of the methods giving access to the properties of a box plot, please consult the QtiPlot/Python API.

7.2.12.22 Distribution Curves

For histograms and box and whiskers plots it is also possible to overlay a distribution curve on the binned data. These curves arenot "fitted" to your data. Instead, QtiPlot determines the data mean, then overlays the curve so that means coincide. If it is a twoparameter curve, QtiPlot takes into account the standard deviation of your data. The following distribution types can be used:

0 DataCurve.NoCurve

1 DataCurve.Normal

2 DataCurve.Lognormal

3 DataCurve.Poisson

4 DataCurve.Exponential

5 DataCurve.Laplace

6 DataCurve.Lorentz

7 DataCurve.Weibull

h = newGraph().activeLayer().addHistogram(table("Table1"), "Table1_2")h.setDistributionCurve(DataCurve.Normal, 50)# the distribution curve is scaled to 50% of ←↩

the maximum bin valueh.loadData()

The following functions give access to the distribution curve and its properties:

dc = h.distributionCurve()dc.setPen(Qt.red)print h.distributionScaleFactor()

When working with box and whiskers plots you can enable the distribution curve in the same way:

g = newGraph().activeLayer()g.plotBox(table("Table1"), "2")box = g.boxCurve(0)box.setDataDisplayMode(BoxCurve.BoxData)box.setSnapDataToBin()g.replot()box.setDistributionCurve(DataCurve.Poisson)box.updateHistogram()box.distributionCurve().setPen(Qt.blue)

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7.2.12.23 Pie Plots

The following script shows how to create and customize a 3D pie plot:

g = newGraph().activeLayer()pie = g.plotPie(table("Table1"), "2")pie.setRadius(70)pie.setViewAngle(40)pie.setThickness(20)pie.setStartAzimuth(45)pie.setLabelsEdgeDistance(50)pie.setCounterClockwise(True)pie.setBrushStyle(Qt.Dense3Pattern)pie.setIncrementPattern(True)pie.setFirstColor(3)pie.setPen(QtGui.QPen(Qt.red, 2))pie.setLabelValuesFormat(True)

Here’s how you can create a 2D black and white pie chart:

pie2D = newGraph().activeLayer().plotPie(table("Table1"), "2")pie2D.setViewAngle(90.0);pie2D.setFirstColor(-1);pie2D.setIncrementPattern();

For an exhaustive review of the methods giving access to the properties of a pie plot, please consult the QtiPlot/Python API.

7.2.12.24 Vector Plots

You can create a vector plot by giving four columns in a Python tuple as an argument and the plot type as Layer.VectXYXY(11) or Layer.VectXYAM (14), depending on how you want to define the end point of your vectors: using (X, Y) coordinates or(Angle, Magnitude) coordinates.

g = qti.app.plot(table("Table1"), (2,3,4,5), Layer.VectXYXY)

In the case of XYAM vector plots you can set a constant angle and/or magnitude, but you still need to specify at least two columnnames in order to define the origin of the vectors. The following script shows how to create and customize XYAM vector curves:

g = newGraph().activeLayer()t = table("Table1")

v = g.plotVectors(t, ["Table1_1", "Table1_2"], Layer.VectXYAM)v.setConstantAngle(135)v.setConstantMagnitude(15)v.setPosition(VectorCurve.Head)

v = g.plotVectors(t, ["Table1_1", "Table1_2", "Table1_3"], Layer.VectXYAM)v.setConstantMagnitude(10)v.setMagnitudeInPixels()v.setVectorPen(Qt.red)

v = g.plotVectors(t, ["Table1_1", "Table1_2", "", "Table1_3"], Layer.VectXYAM)v.setConstantAngle(90)v.setVectorPen(Qt.blue)

v = g.plotVectors(t, ["Table1_1", "Table1_2", "Table1_3", "Table1_4"], Layer.VectXYAM)v.setVectorPen(Qt.green)v.fillArrowHead(False)v.setHeadAngle(15)v.setHeadLength(20)v.setMagnitudeMultiplier(10)v.setPosition(VectorCurve.Middle)

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By default the magnitudes are interpreted in real world coordinates and are used to compute the x, y values of the end point ofthe vector. The magnitudes displayed in the graph will change when the X or Y axes scales are changed, but they will remainconstant in real world coordinates. By using the method setMagnitudeInPixels with the default True argument, themagnitudes will be calculated in pixels and will remain constant when the X or Y axes scales are changed. The same effect canbe obtained by using the setRealWorldMagnitude(False) method.

For an exhaustive review of the methods giving access to the properties of a vector curve, please consult the QtiPlot/Python API.

7.2.12.25 Adding arrows/lines to a plot layer

arrow = ArrowMarker()arrow.setStart(210.5, 212.5)arrow.setEnd(400, 400.51)

#customize linearrow.setStyle(QtCore.Qt.DashLine)arrow.setColor(Qt.red)arrow.setWidth(1)

#customize start arrow headarrow.setStartArrowShape(Layer.VerticalLine)arrow.setStartHeadLength(15)arrow.setStartHeadAngle(25)

#customize end arrow headarrow.setEndArrowShape(Layer.FilledAngle)arrow.setEndHeadLength(20)arrow.setEndHeadAngle(15)

l = newGraph().activeLayer()arrow1 = l.addArrow(arrow)

arrow.setStart(120.5, 320.5)arrow.setColor(Qt.blue)arrow2 = l.addArrow(arrow)

l.remove(arrow1)

As you might notice from the sample code above, the addArrow function returns a reference to a new arrow object that can beused later on to modify this new arrow or to delete it with the remove function.

The shape of an arrow head can take one of the following values:

0. Layer.NoArrow

1. Layer.FilledTriangle

2. Layer.Angle

3. Layer.FilledAngle

4. Layer.EmptyTriangle

5. Layer.Diamond

6. Layer.VerticalLine

7. Layer.HalfLineDown

8. Layer.HalfLineUp

9. Layer.XCross

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10. Layer.Rectangle

11. Layer.Ellipse

It is possible to modify the properties of all the lines/arrows in a plot layer, see the short example below:

l = graph("Graph1").activeLayer()for arrow in l.arrowsList():

arrow.setColor(Qt.green)l.replot()

The number of lines/arrows in a plot layer can be retrieved using the function numArrows:

l = graph("Graph1").activeLayer()print l.numArrows()

Starting with version 0.9.9.3 the functions bellow are deprecated. These methods are still provided in order to keep old sourcecode working but they are no longer maintained. We strongly advise against using them in new code.

drawStartArrow(bool)drawEndArrow(bool)fillArrowHead(bool)setHeadLength(int)setHeadAngle(int)

7.2.12.26 Adding images to a layer

l = newGraph().activeLayer()image = l.addImage("C:/poze/adi/PIC00074.jpg")image.setCoordinates(200, 800, 800, 200)image.setFrameStyle(Frame.Shadow)image.setFrameColor(QtCore.Qt.green)image.setFrameWidth(3)l.replot()

The setCoordinates function above can be used to set the geometry of the image using scale coordinates. If you need tospecify the image geometry in pixel coordinates, independently of the plot axes values, you may use the following functions:

image.setOrigin(x, y)image.setSize(width, height)image.setRect(x, y, width, height)l.replot()

You can remove an image using its reference:

l.remove(image)

7.2.12.27 Rectangles

l = newGraph().activeLayer()

r = Rectangle(l)r.setSize(100, 100)r.setOrigin(100, 200)r.setBackgroundColor(QtCore.Qt.yellow)r.setFrameColor(QtCore.Qt.red)r.setFrameWidth(3)r.setFrameLineStyle(QtCore.Qt.DotLine)r.setBrush(QtGui.QBrush(QtCore.Qt.green, QtCore.Qt.FDiagPattern))

r1 = l.add(r)

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You can remove a rectangle using its reference:

r2 = l.add(r)r2.setOrigin(200, 200)l.remove(r1)

7.2.12.28 Circles/Ellipses

l = newGraph().activeLayer()

e = Ellipse(l)e.setSize(100, 100)e.setOrigin(100, 200)e.setBackgroundColor(QtCore.Qt.yellow)e.setFrameColor(QtCore.Qt.red)e.setFrameWidth(0.8)e.setFrameLineStyle(QtCore.Qt.DotLine)e.setBrush(QtGui.QBrush(QtCore.Qt.green, QtCore.Qt.FDiagPattern))

l.add(e)

7.2.12.29 Color Scale Legends

You can add a color scale legend like in the example bellow:

cs = graph("Graph1").activeLayer().addColorScaleLegend()cs.setOrigin(500, 20)cs.setSize(100, 200)

By default a new color scale is attached to the first plot curve/matrix available in the plot layer, meaning that the color mapdisplayed by the legend is the color map of this plot item. It is possible to change the plot item to which the color scale isattached using the index of the item (starting at zero), like shown bellow:

cs = graph("Graph1").activeLayer().addColorScaleLegend()cs.setPlotItem(1)cs.setOrigin(500, 20)

Please note that if the index argument of the setPlotItem function has a negative value (no plot item attached), than the colorscale legend displays a default color map, that can be customized via the setDefaultColorMap function:

map = LinearColorMap(Qt.yellow, Qt.blue)map.addColorStop(0.2, Qt.magenta)map.addColorStop(0.5, Qt.red)map.addColorStop(0.7, Qt.cyan)

cs = graph("Graph1").activeLayer().colorScaleList()[0]cs.setPlotItem(-1)cs.setDefaultColorMap(map)

The colorScaleList() function provides a list containing the references of all color scale legends available in a plot layer.You can use it in order to get a reference to an already existing color scale legend and to customize it according to your needs.You can change for example its default layout, like shown in the script bellow:

cs = graph("Graph1").activeLayer().colorScaleList()[0]cs.setColorBarWidth(30)# Align the tick labels to the left and vertically centeredcs.setLabelAlignment(Qt.AlignLeft | Qt.AlignVCenter)cs.setAlignment(2) # left scale layout

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# Set the distance between the legend frame and the color bar ends to 15 pixelscs.setBorderDist(15)# Set the distance between the ticks and the tick labels to 10 pixelscs.setLabelSpace(10)cs.setInvertedScale(True)

The alignment of a color scale legend can take one of the following values:

0. Bottom scale

1. Top scale

2. Left scale

3. Right scale. This is the default layout.

By default the color bar of the legend has a black frame. It is possible to remove it:

cs = graph("Graph1").activeLayer().colorScaleList()[0]cs.setDrawColorBarFrame(False)cs.repaint()

or to customize its appearance:

cs = graph("Graph1").activeLayer().colorScaleList()[0]# reenable the drawing of the color bar framecs.setDrawColorBarFrame()# modify the color and line width of the framecs.setColorBarFramePen(QPen(Qt.blue, 2.5))cs.repaint()

The main line ("backbone") of the axis of a color scale legend is hidden by default (the getter function hasBackbone() returnsFalse). It is possible to enable it and customize its appearance, using the functions bellow:

cs = graph("Graph1").activeLayer().colorScaleList()[0]cs.enableBackbone(True)cs.setAxisColor(Qt.blue)cs.setAxisLineWidth(1)# Set the distance between the axis and the color bar to 2 pixelscs.setAxisMargin(2)

By default the title of a color scale legend (returned by the function axisTitle()) is an empty string, but it is possible todefine a custom title:

cs = graph("Graph1").activeLayer().colorScaleList()[0]cs.setAxisTitle("My color scale lagend!")cs.setAxisTitleColor(Qt.blue)cs.setAxisTitleFont(QFont("Courier", 12))cs.setAxisTitleAlignment(Qt.AlignRight)

The layout of the major tick labels can be completely customized using the following functions:

cs = graph("Graph1").activeLayer().colorScaleList()[0]cs.setLabelAlignment(Qt.AlignHCenter| Qt.AlignVCenter)# Set the distance between the ticks and the tick labels to 12 pixelscs.setLabelSpace(12)cs.setLabelRotation(-45)cs.repaint()# makes the changes visible

The font and color of the major tick labels can be also customized using the following functions:

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cs = graph("Graph1").activeLayer().colorScaleList()[0]cs.setLabelFont(QFont("Courier", 12))cs.setLabelColor(Qt.red)

The numerical format of the labels can be set using the function setLabelsNumericFormat(format, precision),where format can have the following values:

0. Automatic: the most compact numeric representation is chosen

1. Decimal: numbers are displayed in floating point form.

2. Scientific: numbers are displayed using the exponential notation.

3. Superscripts: like Scientific, but the exponential part is displayed as a power of 10.

4. Engineering: numbers are displayed using the engineering format.

5. Superscripts: like Superscripts above, but the multiplication sign is replaced by a dot sign.

and precision is the number of significant digits (the default value is 6):

cs = graph("Graph1").activeLayer().colorScaleList()[0]cs.setLabelsNumericFormat(3, 1)cs.updateScale()

Additionally it is possible to define a prefix and/or a suffix for the major tick labels using the functions bellow:

cs = graph("Graph1").activeLayer().colorScaleList()[0]cs.setLabelPrefix("Value: ")cs.setLabelSuffix(" mm")cs.repaint()

Finally it is possible to disable the display of the major tick labels using the function enableLables():

cs = graph("Graph1").activeLayer().colorScaleList()[0]cs.enableLables(False)

The default policy for color scale legends is to display a major tick for each level in the color map. This can be changed usingthe setLevelsDisplayMode function. Its argument can take one of the following values:

0 or ColorScale.AllMajorLevels: A major tick is displayed for each level in the color map.

1 or ColorScale.PartialTotalLevels: A major tick is displayed for every n-th color level, where n can be defined using thesetSkipMajorTicksCount function.

cs = graph("Graph1").activeLayer().colorScaleList()[0]cs.setLevelsDisplayMode(ColorScale.PartialTotalLevels)cs.setSkipMajorTicksCount(1)cs.updateScale()

2 or ColorScale.CustomStepLevels: A major tick is displayed at regular intervals starting with the lowest color level in themap. The step can be defined using the setAxisStep function.

cs = graph("Graph1").activeLayer().colorScaleList()[0]cs.setLevelsDisplayMode(ColorScale.CustomStepLevels)cs.setAxisStep(4.5)cs.updateScale()

3 or ColorScale.CustomCountLevels: The total number of major tick can be defined using the setMajorTicksCountfunction.

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cs = graph("Graph1").activeLayer().colorScaleList()[0]cs.setLevelsDisplayMode(ColorScale.CustomCountLevels)cs.setMajorTicksCount(10)cs.updateScale()

By default a color scale legend has no minor ticks (the getter function minorTicksCount returns zero), but it is possible tomodify their number using the function setMinorTicksCount:

cs = graph("Graph1").activeLayer().colorScaleList()[0]cs.setMinorTicksCount(4)cs.updateScale()

The length of the ticks (both minor and major) can be customized using the function setTicksLength:

cs = graph("Graph1").activeLayer().colorScaleList()[0]cs.setTicksLength(5, 10) # minor ticks have 5 pixels, major ticks 10

Finally, it is possible to disable the display of the ticks:

cs = graph("Graph1").activeLayer().colorScaleList()[0]cs.enableTicks(False)

7.2.12.30 Exporting graphs

Layers and whole graph windows can be printed and exported from within Python. The fastest way to export a graph window orsingle layers is the following:

l.export(fileName)

This function uses some default parameters for the properties of the image. If you need more control over the exported imagesyou can use one of the following specialized functions:

l.exportVector(fileName, size = QtCore.QSizeF(), unit = Frame.Pixel, fontsFactor = 1.0, ←↩color = True)

l.exportImage(fileName, quality = 100, transparent = False, dpi = 0, size = QtCore.QSizeF() ←↩, unit = Frame.Pixel, fontsFactor = 1.0, compression = 0)

l.exportTex(fileName, color = True, escapeStrings = True, fontSizes = True, size = QtCore. ←↩QSizeF(), unit = Frame.Pixel, fontsFactor = 1.0)

When exporting graph windows there is an extra boolean parameter that can be used in order to clip the space around plot layers.This last parameter has no effect if used in conjunction with a custom export size. An example of how you should call thesefunctions can be found bellow:

g = graph("Graph1")g.exportVector("test.pdf", QtCore.QSizeF(), Frame.Pixel, 1.0, True, True)g.exportImage("test.png", 100, True, 0, QtCore.QSizeF(), Frame.Pixel, 1.0, 0, True)g.exportTex("test.tex", True, True, True, QtCore.QSizeF(), Frame.Pixel, 1.0, True)

The function exportVector can export the plot/layer to the following vector formats: .eps, .emf, .ps, .pdf, .svg and .wmf (thislast format is only supported on Windows platforms). The use of the color parameter only makes sense when exporting to .eps,.pdf and .ps formats. For all other formats it is ignored.

The function exportImage can be used if you need to export to one of the Qt supported raster image formats (.bmp, .png,.jpg, etc...). The transparent option can only be used in conjunction with the file formats supporting transprency: .png and.tif (.tiff). The quality parameter influences the size of the output file. The higher this value (maximum is 100), the higher thequality of the image, but the larger the size of the resulting files. The dpi parameter represents the export resolution in pixelsper inch (the default is screen resolution), size is the printed size of the image (the default is the size on screen) and unit isthe length unit used to express the custom size and can take one of the following values:

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0. Inch

1. Millimeter

2. Centimeter

3. Point: 1/72th of an inch

4. Pixel

The fontsFactor parameter represents a scaling factor for the font sizes of all texts in the plot (the default is 1.0, meaningno scaling). If you set this parameter to 0, the program will automatically try to calculate a scale factor. The compressionparameter can be 0 (no compression) or 1 (LZW) and is only effectif for .tif/.tiff images. It is neglected for all other raster imageformats.

The function exportTex can be used if you need to export to a TeX file. The escapeStrings parameter enables/disablesthe escaping of special TeX characters like: $, {, }, ˆ, etc... If True, the fontSizes parameter triggers the export of theoriginal font sizes in the plot layer. Otherwise all exported text strings will use the font size specified in the preamble of the TeXdocument.

All the export functions rely on the file name suffix in order to choose the image format.

7.2.12.31 Arranging Layers

When you are working with many layers in a 2D plot window, setting the layout of these layers manually can be a very tedioustask. With the help of a simple Python script you can make this task very easy and automatically manage the layout of the plotwindow. For example, here’s how you can create a two rows by two columns matrix of layers, each plot layer having a canvassize (the drawing area) of 400 pixels wide and 300 pixels in height:

g = newGraph("Test", 4, 2, 2)g.setLayerCanvasSize(400, 300)g.arrangeLayers(False, True)

The arrangeLayers() function takes two parameters. The first one specifies if the layers should be arranged automatically,using a best-layout algorithm, or if the numbers of rows and columns is fixed by the user. If the value of the second parameter isTrue, the size of the canvas is fixed by the user and the plot window will be enlarged or shrunken, according to the user settings.Otherwise the size of the plot window will be kept and the canvas area of each layer will be automatically adapted to fit this size.Here’s how you can modify the graph created in the previous example, in order to display a row of three layers, while keepingthe size of the plot window unchanged:

g.setNumLayers(3)g.setRows(1)g.setCols(3)g.arrangeLayers(False, False)

By default, the space between two neighboring layers as well as the distance between the layers and the borders of the plotwindow is set to five pixels. You can change the spacing between the layers and the margins using the following functions:

g.setSpacing(x, y)g.setMargins(left, right, top, bottom)

Another aspect of the layout management is the alignment of the layers. There are three alignment flags that you can use for thehorizontal alignment (HCenter, Left, Right) and another three for the vertical alignment (VCenter, Top, Bottom) of the layers.The following code line aligns the layers with the right edge of the window and centers them vertically in the available space:

g.setAlignment(Graph.Right, Graph.VCenter)

The alignment of the layers can be done with respect to the drawing area between the axes (Graph.AlignCanvases) or with respectto the whole layer widget (Graph.AlignLayers) and you can specify the alignment policy to use via the following method:

g.setAlignPolicy(Graph.AlignCanvases)

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A very often needed layout is the one with shared layer axes having linked abscissae (modifying the x scale for one layer willautomatically adjust the scales for all plot layers). Here’s how you can simply create such a 2x2 layers grid, with only a few linesof code:

g = newGraph("", 4, 2, 2)g.setSpacing(0, 0)g.setAlignPolicy(Graph.AlignCanvases)g.setCommonLayerAxes()g.arrangeLayers()g.linkXLayerAxes(True)

All the examples above suppose that the layers are arranged on a grid, but of course you can add layers at any position in the plotwindow. In the examples below the x, y coordinates, in pixels, refer to the position of the top-left corner of the layer. The originof the coordinates system coincides with the top-left corner of the plot window, the y coordinate increasing towards the bottomof the window. If the width and height of the layer are not specified they will be set to the default values. The last argumentspecifies if the default preferences, specified via the Preferences dialog, will be used to customize the new layer (default value isFalse):

g = newGraph()l1 = g.addLayer()l2 = g.addLayer(215, 20)l3 = g.addLayer(10, 20, 200, 200)l4 = g.addLayer(10, 20, 200, 200, True)

You can remove a plot layer using:

l = g.layer(num)g.removeLayer(l)g.removeActiveLayer()

As you have already seen, in a plot window the active layer is, by default, the last layer added to the plot, but you can change itprogramatically:

l = g.layer(num)g.setActiveLayer(l)

In case you need to perform a repetitive task on all the layers in a plot window, you need to use a for loop and of course you needto know the number of layers existing on the plot. Here’s a small example showing how to custom the titles of all the layers inthe plot window:

g = graph("Graph1")layers = g.numLayers()for i in range (1, layers+1):

l = g.layer(i)l.setTitle("Layer"+QtCore.QString.number(i))l.setTitleColor(QtGui.QColor("red"))l.setTitleFont(QtGui.QFont("Arial", 14, QtGui.QFont.Bold, True))l.setTitleAlignment(QtCore.Qt.AlignLeft)

Finally, sometimes it might be useful to be able to swap two layers. This can be done with the help of the following function:

g.swapLayers(layerNum1, layerNum2)

7.2.12.32 Waterfall Plots

Waterfall plots are ideal for comparing variations between multiple data sets created under similar conditions. A pseudo 3Deffect is generated by applying an offset to all the data curves in a 2D plot layer, enabling you to see variations in the Z direction.You can create and customize them using the functions below:

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g = waterfallPlot(table("Table1"), (2, 3, 4))l = g.activeLayer()l.setWaterfallOffset(50, 20)# x/y offsets as % of the layer drawing area width/heightl.setWaterfallSideLines(True) # draw side lines for all the data curvesl.setWaterfallFillColor(Qt.lightGray)g.reverseWaterfallOrder() # reverse the order of the displayed curves

7.2.13 3D Plots

7.2.13.1 Creating a 3D plot

You can plot 3D analytical functions or parametric surfaces. For the 3D functions, the only parameters allowed are x for the theabscissae values and y for the ordinates:

g = plot3D("sin(x*y)", -10.0, 10.0, -10.0, 10.0, -2.0, 2.0)

For the parametric surfaces the only parameters allowed are the latitude and the longitude: u and v. Here’s, for example, howyou can plot a sphere:

g = plot3D("cos(u)*cos(v)", "sin(u)*cos(v)", "sin(v)", -3.14, 3.14, -2, 2)

You can also create 3D height maps using data from matrices and, of course, you can plot table columns:

g = plot3D(matrix("Matrix1"), style = 5)g = plot3D(table("Table1"), "3", style)

In the case of 3D plots created from matrix data sources the style parameter can take any integer value from 1 to 5, with thefollowing signification:

1. Wireframe style

2. Hidden Line style

3. Color filled polygons without edges

4. Color filled polygons with separately colored edges

5. Scattered points (the default style)

For 3D plots created from tables the style parameter can take any integer value from 0 to 3 or the equivalent style values fromthe following list:

0. Graph3D.Scatter

1. Graph3D.Trajectory

2. Graph3D.Bars

3. Graph3D.Ribbon

An alternative method to create a 3D plot is to create an empty plot window and to assign a data source to it. As you have alreadyseen a data source can be an analytical function, a matrix or a table. For large data sets you can increase the drawing speed byreducing the number of points taken into account. The lower the resolution parameter, the higher the number of points used: foran integer value of 1, all the data points are drawn.

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g = newPlot3D("test3D")g.setTitle("My 3D Plot", QtGui.QColor("blue"), QtGui.QFont("Arial",14))g.setResolution(2)g.setFunction("sin(x*y)", -10.0, 10.0, -10.0, 10.0, -2.0, 2.0)#org.setData(table("Table1"), "3")#org.setMatrix(matrix("Matrix1"))

Once a plot is created, you can modify the scales and set the data range to display, using, for example:

g.setScales(-1.0, 1.0, -10.0, 11.0, -2.0, 3.0)

7.2.13.2 Customizing the view

When a new 3D plot is created, the scene view parameters are set to default values. Of course, QtiPlot provides functions tocustomize each aspect of the view. For example, you can set rotation angles, in degrees, around the X, Y and Z axes, respectively,using:

g.setRotation(45, 15, 35)

The following function allows you to shift the plot along the world X, Y and Z axes, respectively:

g.setShift(3.0, 7.0, -4.0)

You can also zoom in/out the entire plot as a whole, or you can zoom along a particular axis:

g.setZoom(10)g.setScale(0.1, 0.05, 0.3)

Also, you can automatically detect the zoom values that fit best with the size of the plot window:

g.findBestLayout()

You can enable/disable the perspective view mode or animate the view using:

g.setOrthogonal(False)g.animate(True)

7.2.13.3 Plot Styles

The style of the 3D plot can be set using the following functions:

g.setPolygonStyle()g.setFilledMeshStyle()g.showLegend(True)g.setHiddenLineStyle()g.setWireframeStyle()g.setAntialiasing(True)g.setMeshLineWidth(0.7)

For scatter plots using points you can specify the radius of the points and their shape: circles if smooth is True, rectanglesotherwise.

g.setDotOptions(10, smooth = True)g.setDotStyle()

Other symbols available for scatter plots are: bars

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g.setBarRadius(0.01)g.setBarLines(False)g.setFilledBars(True)g.setBarStyle()

cones

g.setConeOptions(radius, quality)g.setConeStyle()

and crosses (surrounded by a box frame, if boxed is set to True):

g.setCrossOptions(radius, width, smooth, boxed)g.setCrossStyle()

7.2.13.4 3D Vectors

It is possible to plot 3D vectors using as data source a table that has at least six columns. The code bellow creates a 3D curvewith vector type XYZ dXdYdZ and returns a reference to this curve:

t = table("Table1")c = newPlot3D().addVectors(t, t.colNames(), True)

The second argument of the addVectors function is a string list that must contain six column names. If the third argument isnot specified the type of the 3D vectors is by default set to XYZ XYZ.

Once created the type and the names of the data columns defining the end point of the 3D vector may be changed as shownbellow. The second argument of the setVectorEndZColName function is true in order to reload the data only once (thedefault value is False):

c.setDxDyDz(False)c.setVectorEndXColName("Table1_A")c.setVectorEndYColName("Table1_B")c.setVectorEndZColName("Table1_C", True)

print c.isDxDyDz()print c.vectorEndXColName()print c.vectorEndYColName()print c.vectorEndZColName()

The appearance of a 3D vectors curve c can be customized using the following functions:

c.setVectorColor(Qt.red)c.setVectorLineWidth(2.0)c.setVectorScalingFactor(0.75)

print c.vectorLineWidth()print c.vectorScalingFactor()

The style of the arrow can be customized using the setArrowStyle function. The first argument of this function is the headlength, the second specifies the value in degrees of the head angle, the third is the quality, that is the number of facets usedto draw the arrow head, the forth specifies weather the head is filled or not and the last argument sets the scaling policy for thearrow head. The value of the last argument may be: 0 - no scaling, 1 - logarithmic scaling or 2 - linear scaling.

c.setArrowStyle(0.5, 30, 4, False, 1)

print c.vectorHeadLength()print c.vectorHeadAngle()print c.arrowQuality()print c.hasFilledArrowHead()print c.vectorScaleHeadPolicy()

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7.2.13.5 The 2D Projection

By default the floor projection of the 3D surface plot is disabled. You can enable a full 2D projection or only display the isolinesusing the following functions:

g.showFloorProjection()g.showFloorIsolines()g.setEmptyFloor()

7.2.13.6 The Coordinates System

The coordinates system around the surface plot can be customized to display all the twelve axes, only three of them or none,respectively, with the help of the following functions:

g.setBoxed()g.setFramed()g.setNoAxes()

If the axes are enabled, you can set their legends and the distance between the legend and the axes via:

g.setXAxisLabel("X axis legend")g.setYAxisLabel("Y axis legend")g.setZAxisLabel("Z axis legend")g.setLabelsDistance(30)

It is possible to set the numerical format and precision of the axes using the function below:

g.setAxisNumericFormat(axis, format, precision)

where the first parameter is the index of the axis: 0 for X, 1 for Y and 2 for Z, the second one is the numerical format:

0. Graph3D.Default: decimal or scientific, depending which is most compact

1. Graph3D.Decimal: 10000.0

2. Graph3D.Scientific: 1e4

3. Graph3D.Engineering: 10k

and the last parameter is the precision (the number of significant digits). The following convenience functions are also provided,where you don’t have to specify the index of the axis anymore:

g.setXAxisNumericFormat(1, 3)g.setYAxisNumericFormat(1, 3)g.setZAxisNumericFormat(1, 3)

Also, you can fix the length of the major and minor ticks of an axis:

g.setXAxisTickLength(2.5, 1.5)g.setYAxisTickLength(2.5, 1.5)g.setZAxisTickLength(2.5, 1.5)

7.2.13.7 Grid

If the coordinate system is displayed, you can also display a grid around the surface plot. Each side of the grid can be shown/hid-den:

g.setLeftGrid(True)g.setRightGrid()g.setCeilGrid()g.setFloorGrid()g.setFrontGrid()g.setBackGrid(False)

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7.2.13.8 Customizing the Plot Colors

The default color map of the plot is defined using two colors: red for the maximum data values and blue for the minimum datavalues. You can change these default colors:

g.setDataColors(QtCore.Qt.black, QtCore.Qt.green)g.update()

Of course, you can define more complex color maps, using LinearColorMap objects:

map = LinearColorMap(QtCore.Qt.yellow, QtCore.Qt.blue)map.setMode(LinearColorMap.FixedColors) # default mode is LinearColorMap.ScaledColorsmap.addColorStop(0.2, QtCore.Qt.magenta)map.addColorStop(0.7, QtCore.Qt.cyan)g.setDataColorMap(map)g.update()

Also, you can use predefined color maps stored in .map files. A .map file consists of a of 255 lines, each line defining a colorcoded as RGB values. A set of predefined color map files can be downloaded from QtiPlot web site, in the "Miscellaneous"section.

g.setDataColorMap(fileName)g.update()

The colors of all the other plot elements can be customized as shown below. Don’t forget to update the plot in order to displaythe new colors:

g.setMeshColor(QtGui.QColor("blue"))g.setAxesColor(QtGui.QColor("green"))g.setNumbersColor(QtGui.QColor("black"))g.setLabelsColor(QtGui.QColor("darkRed"))g.setBackgroundColor(QtGui.QColor("lightYellow"))g.setGridColor(QtGui.QColor("grey"))g.setDataColors(QtGui.QColor("red"), QtGui.QColor("orange"))g.setOpacity(0.75)g.update()

7.2.13.9 Exporting

In order to export a 3D plot you need to specify a file name containing a valid file format extension:

g.export(fileName)

This function uses some default export options. If you want to customize the exported image, you should use the followingfunction in order to export to raster image formats:

g.exportImage(fileName, int quality = 100, bool transparent = False, dpi = 0, size = QSizeF ←↩(), unit = Frame.Pixel, fontsFactor = 1.0, compression = 0)

where quality is a compression factor: the larger its value, the better the quality of the exported image, but also the larger thefile size. The dpi parameter represents the export resolution in pixels per inch (the default is screen resolution), size is theprinted size of the image (the default is the size on screen) and unit is the length unit used to express the custom size and cantake one of the following values:

0. Inch

1. Millimeter

2. Centimeter

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3. Point: 1/72th of an inch

4. Pixel

The fontsFactor parameter represents a scaling factor for the font sizes of all texts in the plot (the default is 1.0, meaningno scaling). If you set this parameter to 0, the program will automatically try to calculate a scale factor. The compressionparameter can be 0 (no compression) or 1 (LZW) and is only effectif for .tif/.tiff images. It is neglected for all other raster imageformats.

3D plots can be exported to any of the following vector formats: .eps, .ps, .pdf, .pgf and .svg, using the function below:

g.exportVector(fileName, textMode = 0, sortMode = 1, size = QSizeF(), unit = Frame.Pixel, ←↩fontsFactor = 1.0)

where textMode is an integer value, specifying how texts are handled. It can take one of the following values:

0. All text will be converted to bitmap images (default).

1. Text output in the native output format.

2. Text output in additional LaTeX file as an overlay.

The sortMode parameter is also an integer value and can take one of the following values:

0. No sorting at all.

1. A simple, quick sort algorithm (default).

2. BSP sort: best algorithm, but slow.

The other parameters have the same meaning as for the export of 2D plots.

7.2.14 Data Analysis

7.2.14.1 Introduction

As you will see in the following subsections, the data analysis operations available in QtiPlot are: convolution/deconvolution,correlation, differentiation, FFT, filtering, smoothing, fitting and numerical integration of data sets. Generally, you can de-clare/initialize an analysis operation using one of the following methods, depending on the data source, which can be a 2D plotcurve or a table:

op = LogisticFit(graph("Graph1").activeLayer().curve(0), 15.2, 30.9)op = FFTFilter(graph("Graph1").activeLayer(), "Table1_2", 1.5, 3.9)op = LinearFit(table("Table1"), "colX", "colY", 10, 100)

In the first example the data source is a curve Table1_2, plotted in the active layer of the graph Graph1 and the abscissae rangeis chosen between 1.5 and 3.9. In the second example the data source is a table Table1. The abscissae of the data set are storedin the column called colX and the ordinates in the column colY. The data range is chosen between the 10th row and the row withthe index 100. If you don’t specify the row range, by default the whole table will be used. Not all operations support curves asdata sources, like for example: convolution/deconvolution and correlation. For these operations only table columns can be usedas data sources for the moment.

Once you have initialized an operation, you can still change its input data via the following functions:

op.setDataFromCurve(graph("Graph2").activeLayer().curve(1), 10.5, 20.1)op.setDataFromCurve("Table1_energy", 10.5, 20.1, graph("Graph2").activeLayer())op.setDataFromTable(table("Table1"), "colX", "colY", 10, 100)

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You don’t have to specify a plot layer in the setDataFromCurve() function, if the analysis operation has already been initializedby specifying a curve on an existing graph and you just want to treat another curve from the same plot layer.

It is possible to sort the input data before performing the analysis operation:

op.setSortData(True)

Also, when performing analysis tasks via Python scripts, there are several utility functions that can be called for all operations.For example you can disable any graphical output from an operation or you can redirect the output to the plot layer of yourchoice:

op.enableGraphicsDisplay(False)op.enableGraphicsDisplay(True, graph("Graph2").activeLayer())

Let’s assume that you need to perform a specific operation op, which analyzes your data and at the end, displays a result curve.For this kind of operations, you can customize the number of points in the resulting curve and its color:

op.setOutputPoints(int)op.setColor(int)op.setColor("green")

Colors can be specified by their names or as integer values, from 0 to 23, each integer corresponding to a predefined color: 0 -"black", 1 - "red", 2 - "green", 3 - "blue", 4 - "cyan", 5 - "magenta", 6 - "yellow", 7 - "darkYellow", 8 - "navy", 9 - "purple", etc ...

The result plot curve generated after an anlysis operation can be accessed via the following function:

c = op.resultCurve()

Most of the time, a new table is also created as a result of a data analysis operation. This table stores the data displayed by theresult curve and is hidden by default, but you can interact with it via the following function:

t = op.resultTable()

After the initialization of an analysis operation, which consists of setting the data source, the data range and some other properties,like color, number of points, etc..., you can execute it via a call to its run() function:

op.run()

For data fitting operations, there’s an alias for the run() function which is: fit().

7.2.14.2 Analysis Filters

All data analysis operations are derived from the same base class, Filter, therefore we will generically call them filters. The typeof an analysis filer can be obtained using the filterType() function. The folowing filter types are defined in the QtiPlot PythonAPI:

0. Filter.FitLinear

1. Filter.FitLinearSlope

2. Filter.FitPoly

3. Filter.FitExp

4. Filter.FitTwoExp

5. Filter.FitThreeExp

6. Filter.FitLogistic

7. Filter.FitSigmoidal

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8. Filter.FitGaussAmp

9. Filter.FitMultiPeak

10. Filter.FitPlugIn

11. Filter.FitUser

12. Filter.Interpolate

13. Filter.Smooth

14. Filter.FindPeaks

15. Filter.Fft

16. Filter.FftFilter

17. Filter.Integrate

18. Filter.Differentiate

19. Filter.Correlate

20. Filter.Convolve

21. Filter.Deconvolve

In a plot layer, as a result of the various analysis operations performed on the data curves, there might be several filter objects. Itis possible to access each of these filters and to get information about them as shown in the sample script bellow:

g = graph("Graph1").activeLayer()for i in range(0, g.filterCount()):

f = g.filter(i)print f.filterType(), f.explanation()if f.filterType() == Filter.FitMultiPeak:print f.profile()

For all filters that display a result curve in a plot layer there is a mechanism available in QtiPlot that allows to trigger a recalcu-lation when the data source is modified. The recalculate mode of a filter can be one of the following:

0 (NoRecalculate): no recalculation when data changes.

1 (AutoRecalculate): a recalculation is automatically performed when input data changes.

2 (ManualRecalculate): no recalculation is triggered when data changes, instead the user can perform a recalculation at any timeusing the recalculate() function.

The sample script bellow shows how to access and modify the recalculate mode and how to perform a recalculation of the dataanalysis operations from a plot layer:

g = graph("Graph1").activeLayer()for i in range(0, g.filterCount()):

f = g.filter(i)if f.recalculateMode() == Filter.AutoRecalculate:f.setRecalculateMode(Filter.ManualRecalculate)

if f.hasModifiedData():f.recalculate()

A filter object f can be added to a plot layer g using the addFilter method:

g = graph("Graph1").activeLayer()g.addFilter(f)

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Please note that if the recalculation policy defined via the Fitting tab of the Preferences dialog is not set to No, data fit objects areadded by default to the output graph layer. For all the other analysis filter types you need to use the addFilter function.

It is possible to remove all filter objects from a plot layer g with a single line of code:

g.deleteFilters()

It is also possible to remove individual filter objects:

for i in range(0, g.filterCount()):g.deleteFilter(g.filter(i))

7.2.14.3 Correlation, Convolution/Deconvolution

Assuming you have a table named "Table1", here’s how you can calculate the convolution of two of its columns, "Table1_B" and"Table1_C":

conv = Convolution(table("Table1"), "B", "C")conv.setColor("green")conv.run()

The deconvolution and the correlation of two data sets can be done using a similar syntax:

dec = Deconvolution(table("Table1"), "B", "C")dec.run()

cor = Correlation(table("Table1"), "B", "C", 10, 200)cor.setColor("green")cor.run()

7.2.14.4 Differentiation

Assuming you have a Graph named "Graph1" containing one curve (on its active layer), here’s how you can differentiate thiscurve within a defined x interval, [2,10] in this case:

diff = Differentiation(graph("Graph1").activeLayer().curve(0), 2, 10)diff.run()

The result of this code sequence would be a new plot window displaying the derivative of the initial curve. The numericalderivative is calculated using a five terms formula.

It is also possible to differentiate data directly from a table without displaying any graphical output:

diff = Differentiation(table("Table1"), "1", "2")diff.enableGraphicsDisplay(False)diff.run()diff.resultTable().showNormal()

The result of the above code sequence is a new table window containing the derivative of the data from the initial table "Table1".

7.2.14.5 FFT

Assuming you have a graph named "Graph1" containing one curve on its active layer and having a periodicity of 0.1 in the timedomain, a FFT will allow you to extract its characteristic frequencies. The results will be stored in a hidden table named "FFT1".

fft = FFT(graph("Graph1").activeLayer().curve(0))fft.normalizeAmplitudes(False)fft.shiftFrequencies(False)fft.setSampling(0.1)fft.run()

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By default the calculated amplitudes are normalized and the corresponding frequencies are shifted in order to obtain a centeredx-scale. If we want to recover the initial curve with the help of the inverse transformation, we mustn’t modify the amplitudes andthe frequencies. Also the sampling parameter must be set to the inverse of the time period, that is 10. Here’s how we can performthe inverse FFT, using the "FFT1" table, in order to recover the original curve:

ifft = FFT(table("FFT1"), "Real", "Imaginary")ifft.setInverseFFT()ifft.normalizeAmplitudes(False)ifft.shiftFrequencies(False)ifft.setSampling(10)ifft.run()

You can also perform 2D fast Fourrier transforms on matrices. The FFT routine takes in this case the following parameters: rm- specifies the real part input matrix, im - specifies the imaginary part input matrix, inverse - specifies the direction of the FFT,DCShift - if this is true, the DC component will be put in the center of the result matrix, otherwise, the DC component will locateat four corners of the result matrix, norm - specifies whether or not to normalize the amplitudes to 1, outputPower2Sizes - forcesoutput matrices whose sizes are integer powers of 2 (zero padding is used to initialize the missing cells)

fft = FFT(Matrix *rm, Matrix *im = NULL, bool inverse = False, bool DCShift = True, bool ←↩norm = False, bool outputPower2Sizes = True)

Here’s how you can perform the 2D FFT of a matrix called "Matrix1", and the inverse FFT in order to recover the original image:

from qti import *m = matrix("Matrix1")m.setViewType(Matrix.ImageView) # make sure the matrix is displayed as image

fft = FFT(m)fft.run()fft.amplitudesMatrix().resize(500, 400)

rMatrix = fft.realOutputMatrix()rMatrix.hide()iMatrix = fft.imaginaryOutputMatrix()iMatrix.hide()

ifft = FFT(rMatrix, iMatrix, True)ifft.run()ifft.realOutputMatrix().hide()ifft.imaginaryOutputMatrix().hide()

7.2.14.6 FFT Filters

In this section, it will be assumed that you have a signal displayed in a graph ("Graph1", on its active layer). This signal hasa power spectrum with high and low frequencies. You can filter some of these frequencies according to your needs, using aFFTFilter. Here’s how you can cut all the frequencies lower than 1 Hz:

filter = FFTFilter(graph("Graph1").activeLayer().curve(0), FFTFilter.HighPass)filter.setCutoff(1)filter.run()

Here’s how you can cut all the frequencies lower than 1.5 Hz and higher than 3.5 Hz. In the following example the continuouscomponent of the signal is also removed:

filter.setFilterType(FFTFilter.BandPass)filter.enableOffset(False)filter.setBand(1.5, 3.5)filter.run()

Other types of FFT filters available in QtiPlot are: low pass (FFTFilter.LowPass) and band block (FFTFilter.BandBlock).

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7.2.14.7 Fitting

Assuming you have a graph named "Graph1" displaying a curve entitled "Table1_2" on its active layer, a minimal Fit examplewould be:

f = GaussFit(graph("Graph1").activeLayer().curve(0))f.guessInitialValues()f.fit()

This creates a new GaussFit object on the curve, lets it guess the start parameters and does the fit. The following fit types aresupported:

• LinearFit(curve)

• LinearSlopeFit(curve)

• PolynomialFit(curve, degree=2, legend=False)

• ExponentialFit(curve, growth=False)

• TwoExpFit(curve)

• ThreeExpFit(curve)

• GaussFit(curve)

• GaussAmpFit(curve)

• LorentzFit(curve)

• LogisticFit(curve)

• SigmoidalFit(curve)

• PsdVoigt1Fit(curve)

• PsdVoigt2Fit(curve)

• MultiPeakFit(curve, xStart, xEnd, profile=MultiPeakFit.Gauss, peaks=1)

f = MultiPeakFit(graph("Graph1").activeLayer().curve(0),100,900,MultiPeakFit.PsdVoigt1,3)f.guessInitialValues()f.setPeakCurvesColor(Qt.green)f.generateFunction(True, 1000)f.run()

The following peak profile functions are available: Gauss, Lorentz, PsdVoigt1 and PsdVoigt2.

• NonLinearFit(curve)

f = NonLinearFit(layer, curve)f.setFormula(formula_string)f.save(fileName)

• PluginFit(curve)

f = PluginFit(curve)f.load("/Applications/qtiplot.app/Contents/MacOS/fitPlugins/libexp_saturation.dylib")

For each of these, you can optionally restrict the X range that will be used for the fit, like in:

f = LinearFit(graph("Graph1").activeLayer().curve(0), 2, 7)f.fit()

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An alternative way to initialize fit objects is to use directly a source data table instead of a plot curve:

f = LinearFit(table("Table1"), "xCol", "yCol", 2, 21) #from start row 2 to end row 21f.fit()

It is possible to restrict the search range for any of the fit parameters:

f = NonLinearFit(graph("Graph1").activeLayer().curve(0))f.setFormula("a0+a1*x+a2*x*x")f.setParameterRange(parameterIndex, start, end)

All the settings of a non-linear fit can be saved to an XML file and restored later one, using this file, for a faster editing process.Here’s for example how you can save the above fit function:

f.save("/fit_models/poly_fit.txt")

and how you can use this file during another fitting session, later on:

f = NonLinearFit(graph("Graph1").activeLayer(), "Table1_2")f.load("/fit_models/poly_fit.txt")f.fit()

If your script relies on a specific numbering of the fit parameters use setParameters() before setting the formula and switch ofautomatic detection of the fit parameters when the fit formula is set:

f.setParameters("a2","a0","a1")f.setFormula("a0+a1*x+a2*x*x",0)

After creating the Fit object and before calling its fit() method, you can set a number of parameters that influence the fit:

f.setDataFromTable(table("Table4"), "w", "energy", 10, 200, True) #change data source (last ←↩parameter enables/disables data sorting)

f.setDataFromCurve(curve) #change data sourcef.setDataFromCurve(curveTitle, graph) #change data sourcef.setDataFromCurve(curve, from, to) #change data sourcef.setDataFromCurve(curveTitle, from, to, graph) #change data sourcef.setInterval(from, to) #change data rangef.setInitialValue(number, value)f.setInitialValues(value1, ...)f.guessInitialValues()f.setAlgorithm(algo) # algo = Fit.ScaledLevenbergMarquardt, Fit.UnscaledLevenbergMarquardt, ←↩

Fit.NelderMeadSimplexf.setWeightingData(method, colname) # method = Fit.NoWeighting, Fit.Instrumental, Fit. ←↩

Statistical, Fit.Dataset, Fit.Directf.setTolerance(tolerance)f.setMaximumIterations(number)f.scaleErrors(yes = True)f.setColor("green") #change the color of the result fit curve to green (default color ←↩

is red)

After you’ve called fit(), you have a number of possibilities for extracting the results:

f.results()f.errors()f.residuals()f.dataSize()f.numParameters()f.parametersTable("params")f.covarianceMatrix("cov")

Writing the fit results to log is a time consuming operation and, especially when you need to perform a large number of fits, youcan disable/enable this functionality using:

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setWriteFitResultsToLog(False) # the boolean parameter of this method is True by default

It is possible to customize the display of the fit results in terms of numerical format and precision:

f.setOutputFormat(’f’)f.setOutputPrecision(2)

The value of the precision parameter for the setOutputPrecision() function has a different meaning depending on thenumeric format. The following format and precision options are available:

’g’ - Decimal or scientific e-notation, whichever is the most concise. The precision represents the maximum number of signifi-cant figures in the output (trailing zeroes are omitted).

’f’ - Decimal notation. The precision represents the number of digits after the decimal point.

’e’ - Scientific e-notation where the letter e is used to represent "times ten raised to the power of" and is followed by the valueof the exponent. The precision represents the number of digits after the decimal point.

There are a number of statistical functions allowing you to test the goodness of the fit:

f.chiSquare()f.rSquare()f.adjustedRSquare()f.rmse() # Root Mean Squared Errorf.rss() # Residual Sum of Squares

Also you can display the confidence and the prediction limits for the fit, using a custom confidence level:

f.showPredictionLimits(0.95)f.showConfidenceLimits(0.95)

Confidence limits for individual fit parameters can be calculated using:

f.lcl(parameterIndex, confidenceLevel)f.ucl(parameterIndex, confidenceLevel)

where parameterIndex is a value between zero and f.numParameters() - 1.

It is important to know that QtiPlot can generate an analytical formula for the resulting fit curve or a normal plot curve with datastored in a hidden table. You can choose either of these two output options, before calling the fit() instruction, using:

f.generateFunction(True, points=100)

If the first parameter of the above function is set to True, QtiPlot will generate an analytical function curve. If the pointsparameter is not specified, by default the function will be estimated over 100 points. You can get the analytical formula of the fitcurve via a call to resultFormula():

formula = f.resultFormula()print(formula)

If the first parameter of generateFunction() is set to False, QtiPlot will create a hidden data table containing the same number ofpoints as the data set/curve to be fitted (same abscissae). You can interact with this table and extract the data points of the resultfit curve using:

t = f.resultTable()

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7.2.14.8 Integration

With the same assumptions as above, here’s how you can integrate a curve within a given interval:

integral = Integration(graph("Graph1").activeLayer().curve(0), 2, 10)integral.run()result = integral.area()

The script bellow shows how to perform an integration on a data set from a table:

i = Integration(table("Table1"), "Table_1", "Table_2", 3, 20, True)# sorted data range from ←↩row 3 to 20

i.enableGraphicsDisplay(False)i.run()result = i.area()

As you can see from the above examples, the numerical value of the integral can be obtained via the area() function.

7.2.14.9 Interpolation

The interpolation is used to generate a new data curve with a high number of points from an existing data set. Here’s an example:

interpolation = Interpolation(graph("Graph1").activeLayer().curve(0), 2, 10, Interpolation. ←↩Linear)

interpolation.setOutputPoints(10000)interpolation.setColor("green")interpolation.run()

The simplest interpolation method is the linear method. There are two other methods available: Interpolation.Akima andInterpolation.Cubic. You can choose the interpolation method using:

interpolation.setMethod(Interpolation.Akima)

It is possible to evaluate the resulting spline at a certain x value:

print interpolation.evalAt(1.5)

The script bellow shows how to perform an interpolation on a data set from an existing table using all three available methods.The script also creates a plot of the original data set together with the interpolated splines:

t = table("Table1") # existing source data tablet2 = newTable(50, 4) # we create an output table

interpol = Interpolation(t, "Table1_1", "Table1_2", Interpolation.Linear)for i in range (1, t2.numRows() + 1):

x = 0.05*it2.setCellData(1, i, x)t2.setCellData(2, i, interpol.evalAt(x))

interpol.setMethod(Interpolation.Cubic)for i in range (1, t2.numRows() + 1):

t2.setCellData(3, i, interpol.evalAt(0.05*i))

interpol.setMethod(Interpolation.Akima)for i in range (1, t2.numRows() + 1):

t2.setCellData(4, i, interpol.evalAt(0.05*i))

g = qti.app.plot(t, 2, Layer.LineSymbols).activeLayer() # plot input data setg.addCurves(t2, (2, 3, 4), Layer.Line) # add interpolated splines to the plot layer

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7.2.14.10 Smoothing

Assuming you have a graph named Graph1 with an irregular curve entitled Table1_2 (on its active layer). You can smooththis curve using a SmoothFilter:

smooth = SmoothFilter(graph("Graph1").activeLayer().curve(0), SmoothFilter.Average)smooth.setSmoothPoints(10)smooth.run()

The default smoothing method is the mowing window average. Other smoothing methods are the SmoothFilter.FFT,SmoothFilter.Lowess and SmoothFilter.SavitzkyGolay. Here’s an example of how to use the last two methods:

smooth.setMethod(SmoothFilter.Lowess)smooth.setLowessParameter(0.2, 2)smooth.run()

smooth.setSmoothPoints(5,5)smooth.setMethod(SmoothFilter.SavitzkyGolay)smooth.setPolynomOrder(9)smooth.run()

7.2.14.11 Find Peaks

A FindPeaksFilter can be used to search the positions of the peaks in a data curve. Assuming you have an input data table namedTable1, containing two columns, the following script demonstrates the usage of this type of filter:

g = qti.app.plot(table("Table1"), 2, Layer.Line).activeLayer() # plot input data set

f = FindPeaksFilter(g.curve(0))f.setPeakFindingAlgorithm(FindPeaksFilter.FirstDerivative)

# smooth input data curve before performing the actual searchf.setMethod(SmoothFilter.Average)f.setSmoothPoints(3)

f.setThreshold(15) # set the detection crierion

f.setRecalculateMode(Filter.AutoRecalculate)f.enableGraphicsDisplay(True, g)f.run()

c = f.resultCurve()c.setLineStyle(PlotCurve.Sticks)

g.addFilter(f)

#print the resultsfor i in range (0, f.peakCount()):

print f.center(i), f.height(i)

From the example above you may notice that it is possible to smooth the input curve using the data smoothing methods describedin the previous section (Smoothing) before performing the actual search for the local extrema.

The available algorithms for searching the peaks are: FindPeaksFilter.QuickSearch and FindPeaksFilter.FirstDerivative. A detection threshold for the local extrema can be set using the setThreshold function and represents apercentage of the difference between the maximum and minimum values of the input data. The default value is 10 %.

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7.2.15 Statistics

7.2.15.1 Descriptive Statistics

stats = Statistics("Table1_2")stats.run()

print stats.mean()print stats.variance()print stats.standardDeviation()print stats.standardError()

For all the statistic test below, once you have created a test object, you can use the following methods:

test.showResultsLog(False) # disable the logging of the resultstest.showDescriptiveStatistics(False) # disable the display of the descriptive statistics ←↩

resultstest.run()

print test.statistic()print test.pValue()print test.logInfo()

t = test.resultTable("MyResultTable") # Returns a pointer to the table created to display ←↩the results (the table name is optional)

7.2.15.2 Hypothesis Testing - Student’s t-Test

test = tTest(15.2, 0.05, "Table1_2") # One sample test, test mean = 15.2, significance ←↩level = 0.05

test.run()

test.setTestValue(15.0)test.setSignificanceLevel(0.5)test.setTail(tTest.Left) # or tTest.Right, or tTest.Both (default value)test.run()

print test.t() # same as test.statistic()print test.dof() # degrees of freedomprint test.power(0.5)print test.power(0.5, 50) # alternative sample size = 50print test.pValue()print test.lcl(90) # lower confidence limit for meanprint test.ucl(90) # upper confidence limit for mean

test = tTest(15.2, 0.05, "Table1_1", "Table1_2", True) # Two sample paired testprint test.logInfo()

test = tTest(15.2, 0.05, "Table1_1", "Table1_2") # Two sample independent testtest.run()

test.setSample1("Table2_1")test.setSample2("Table3_2", True) # Two sample paired testtest.run()

7.2.15.3 One Sample Test for Variance (Chi-Square Test)

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test = ChiSquareTest(88.2, 0.05, "Table1_2") # Test variance = 88.2, significance level = ←↩0.05

test.run()

print test.chiSquare() # same as test.statistic()print test.pValue()print test.logInfo()

7.2.15.4 Normality Test (Shapiro - Wilk)

test = ShapiroWilkTest("Table3_1")test.setSignificanceLevel(0.1)test.run()

print test.w() # same as test.statistic()print test.pValue()print test.logInfo()

7.2.15.5 One-Way ANOVA

Please read the documentation of the TAMUANOVA library for more details.

test = Anova()test.setSignificanceLevel(0.1) # default level is 0.05test.addSample("Table1_1");test.addSample("Table1_2");test.addSample("Table1_3");test.run()

print test.fStat() # F statistic = ssm/sse (same as test.statistic())print test.pValue()print test.ssm() # "between-group" sum of squaresprint test.sse() # "within-group" sum of squaresprint test.sst() # total sum of squares

test.showDescriptiveStatistics(False)print test.logInfo()

7.2.15.6 Two-Way ANOVA

Please read the documentation of the TAMUANOVA library for more details.

test = Anova(True)test.addSample("Table1_1", 1, 1) # Level factor A = 1, level factor B = 1test.addSample("Table1_2", 1, 2) # Level factor A = 1, level factor B = 2test.addSample("Table1_3", 2, 1) # Level factor A = 2, level factor B = 1test.addSample("Table1_4", 2, 2) # Level factor A = 2, level factor B = 2test.setAnovaTwoWayModel(2) # Fixed model = 0, Random model = 1, Mixed model = 2test.run()

print test.fStatA() # F statistic for factor Aprint test.fStatB() # F statistic for factor Bprint test.fStatAB() # F statistic for the interactionprint test.pValueA() # P value for factor Aprint test.pValueB() # P value for factor Bprint test.pValueAB() # P value for the interaction

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print test.ssa() # sum of squares for factor Aprint test.ssb() # sum of squares for factor Bprint test.ssab() # sum of squares for the interactionprint test.msa() # mean square value for factor Aprint test.msb() # mean square value for factor Bprint test.msab() # mean square value for the interaction

print test.logInfo()

7.2.16 Working with Notes

The following functions are available when dealing with multi-tab notes:

setAutoexec(on = True)

text()setText(text)

exportPDF(fileName)saveAs(fileName)importASCII(fileName)

showLineNumbers(on = True)

setFont(QFont f)setTabStopWidth(int length)

tabs()addTab()removeTab(tabIndex)renameTab(tabIndex, title)

e = editor(int index)e = currentEditor()

It is possible to trigger the execution of a script in a Notes window tab:

e = note("Notes1").currentEditor()e.executeAll()# Check if the script is still running:print e.isRunning()

It is also possible to program a script to be run periodically:

e = note("Notes1").currentEditor()e.executePeriodically(3.5) # running interval is set to 3.5 secondsprint e.isRunningPeriodically() # should print Trueprint e.runningInterval() # should print 3.5

In order to stop the periodic execution of a script you may use:

note("Notes1").currentEditor().stopPeriodicExecution()

7.2.17 Using PyQt’s dialogs and classes

Let’s assume that you have a lot of ASCII data files to analyze. Furthermore, let’s suppose that these files were created duringseveral series of measurements, each measurement generating a set of files identified by a certain string in the file name, like forexample: "disper1". In order to analyze these files, you need first of all to import them into tables. The following code snippetshows how to automate this task using PyQt dialogs and convenience classes:

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# Pop-up a file dialog allowing to chose the working folder:dirPath = QFileDialog.getExistingDirectory(qti.app, "Choose Working Folder", "/test/")# Create a folder object using Qt’s QDir class:folder = QDir(dirPath)# Pop-up a text input dialog allowing to chose the file naming pattern:namePattern,ok = QInputDialog.getText(qti.app,"Pattern","Text:",QLineEdit.Normal,"disper1")if ok: # get the list of file names in the working directory containing the above pattern

fileNames = folder.entryList(QStringList ("*" + namePattern + "*.dat"))for i in range (0, fileNames.count()): # import each file into a new project tablenewTable().importASCII(dirPath + "/" + fileNames[i],";")

For a detailed description of all the dialogs and utility classes provided by Qt/PyQt please take a look at the PyQt documentation.

7.2.18 Using Qt Designer for easy creation of custom user dialogs

Writing and designing user dialogs can be a very complicated task. The QtDesigner application provided by the Qt frameworkmakes it easy and very pleasant. It allows you to design widgets, dialogs or complete main windows using on-screen forms anda simple drag-and-drop interface. Qt Designer uses XML .ui files to store designs. Once you have finished the design processyou can load and use an .ui file in your Python scripts with the help of the uic module.

As an example, suppose that we have created a test dialog containing an input QDoubleSpinBox called "valueBox" and a QPush-Button called "okButton". On pressing this button, we would like to create a new table displaying the input value in its first cell.We have saved this dialog to a file called "myDialog.ui". A minimalistic approach is shown in the small script below:

def createTable():t = newTable()t.setCell(1, 1, ui.valueBox.value())

ui = uic.loadUi("myDialog.ui")ui.connect(ui.okButton, QtCore.SIGNAL("clicked()"), createTable)ui.show()

For more details about how to use .ui files in your Python scripts please read the PyQt documentation.

7.2.19 Task automation example

Below you can find a detailed example showing how to completely automatize tasks in QtiPlot. It can be used in order to verifythe accuracy of the curve fitting algorithms in QtiPlot. The test data files that must be used with this example were retrievedfrom the Statistical Reference Datasets Project of the National Institute of Standards and Technology (NIST). In order to run thisexample, you first need to download und unzip the nonlinear regression test files from the QtiPlot website.

Please note that the script can be used as it is only if QtiPlot was built using the Qt 4 library. Otherwise, if QtiPlot was built usingQt 5, it is necessary to adapt the script since QString API is no longer available in this case.

import sys

# Pop-up a file dialog allowing to chose the data folder:dirPath = QFileDialog.getExistingDirectory(qti.app, "Choose Strd-NIST Data Folder")

saveout = sys.stdout # backup default option for sys.stdout

# create a log file in the data folderresultsPath = dirPath + "/" + "results.txt"fsock = open(resultsPath, "w")sys.stdout = fsock

# make sure that the decimal separator is the dot characterqti.app.setLocale(QtCore.QLocale.c())

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# Create a folder object using Qt’s QDir class:folder = QDir(dirPath)# get the list of *.dat files from the data folderfiles = folder.entryList(["*.dat"])count = len(files)for i in range (0, count):

name = files[i]path = dirPath + "/" + nameprint str(i + 1) + ") Parsing data file: " + path + " ..."

file = QtCore.QFile(path)if file.open(QtCore.QIODevice.ReadOnly):ts = QtCore.QTextStream(file)name = name.replace(".dat", "")changeFolder(addFolder(name)) #create a new folder and move to itformula = ""parameters = 0initValues = list()certifiedValues = list()standardDevValues = list()xLabel = "X"yLabel = "Y"

while (ts.atEnd() == False):s = ts.readLine().simplified()

if (s.contains("(y = ")):lst = s.split("=")yLabel = lst[1].remove(")")

if (s.contains("(x = ")):lst = s.split("=")xLabel = lst[1].remove(")")

if (s.contains("Model:")):s = ts.readLine().simplified()lst = s.split(QtCore.QRegExp("\\s"))s = lst[0]parameters = s.toInt()[0]ts.readLine()if (name == "Roszman1"):ts.readLine()formula = ts.readLine().simplified()

else:formula = (ts.readLine() + ts.readLine() + ts.readLine()).simplified()

formula.remove("+ e").remove("y =").replace("[", "(").replace("]", ")")formula.replace("**", "^").replace("arctan", "atan")

if (s.contains("Starting")):ts.readLine()ts.readLine()for i in range (1, parameters + 1):s = ts.readLine().simplified()lst = s.split(" = ")s = lst[1].simplified()lst = s.split(QtCore.QRegExp("\\s"))initValues.append(lst[1])certifiedValues.append(lst[2])standardDevValues.append(lst[3])

if (s.contains("Data: y")):row = 0

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t = newTable(name, 300, 2)t.setColName(1, "x")t.setColName(2, "y")while (ts.atEnd() == False):row = row + 1s = ts.readLine().simplified()lst = s.split(QtCore.QRegExp("\\s"))t.setText(1, row, lst[1])t.setText(2, row, lst[0])

g = plot(t, t.colName(2), Layer.Scatter).activeLayer()g.setTitle("Data set: " + name + ".dat")g.setAxisTitle(Layer.Bottom, xLabel)g.setAxisTitle(Layer.Left, yLabel)

f = NonLinearFit(g.curve(0))f.setObjectName(name)f.setFormula(formula)f.scaleErrors()for i in range (0, parameters):f.setInitialValue(i, initValues[i].toDouble()[0])

f.fit()print "\nQtiPlot Results:\n" + f.legendInfo().remove("").remove("")print "\nCertified Values:"

paramNames = f.parameterNames()for i in range (0, parameters):print ’%s = %s +/- %s’ % (paramNames[i], certifiedValues[i], standardDevValues[i ←↩

])

print "\nDifference with QtiPlot results:"results = f.results()for i in range (0, parameters):diff = fabs(results[i] - certifiedValues[i].toDouble()[0])print ’db%d = %6E’ % (i+1, diff)

print("\n")

file.close()changeFolder(rootFolder())

print "Done parsing " + str(count) + " files.\n"fsock.close()# close output results filesys.stdout = saveout # restore initial sys.stdout

resNote = newNote("ResultsLog")resNote.importASCII(resultsPath)resNote.showMaximized()

saveProjectAs(dirPath + "/" + "StRD_NIST.qti")

7.2.20 Scope Changes

In recent versions the scope rules were changed to match standard Python:

• The keyword "global" refers to the module, e.g. a particular script window or column script. Outside of any function, this is thedefault namespace, so "global x" has no effect. Inside a function, "global x" refers to x in the module namespace. Previously,"global" referred to QtiPlot’s global variables, and module-level variables were inaccessible from inside a function, unlessmarked global.

• To read and write QtiPlot’s global variables, use the new special variable globals:

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globals.myvar = 5print globals.myvar

globals is shared among all modules.

If a script has any "global" declaration outside of a function, QtiPlot uses the old scope rules. Existing scripts should keepworking, but for best results, update your scripts:

• If a "global" variable x is used only within one script, delete any "global x" that is outside of a function.

• If a "global" variable needs to be accessed outside the script that defined it, change

global xx = 5

to

globals.x = 5

and replace all references to x with globals.x

7.2.21 QtiPlot/Python API

The complete QtiPlot/Python API can be consulted here.

7.2.22 PyQt Class Reference

The complete PyQt class reference can be consulted here.

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Chapter 8

Frequently asked questions

Q: How can I visualise data from a text file?

A: Go to the File menu and select the Import -> Import ASCII... command.

Q: How can I plot data from a table (worksheet)?

A: Click on the table header to choose the columns to plot and then right click. Chose the ’Plot’ option from the pop-up menuand then the type of plot you want.You can also use the plot assistant: press ’CTRL+ALT+W’ keys to show it, or go to ’View’menu -> ’Plot wizard’.

Q: How can I export a plot to an image format?

A: Right click in the plot window and chose the ’Export’ option.

Q: Can I export transparent images?

A: Yes, ".png" images have transparent background. See the Export Graph -> Current command.

Q: How can I export a text file?

A: Go to the File menu and select the Export ASCII dialog.

Q: How can I choose a window using the project explorer?

A: Double click on the window name will show the window maximized, even if it was hidden before.

Q: How can I choose the data range from a plot curve, when doing a curve fit?

A: Go to the Data menu and use the Select Data Range command. Click in the plot window and use the ’Up’ and ’Down’ arrowskeys to select the curve to analyse. Keeping ’CTRL’ button and ’Left’ or ’Right’ arrow keys simultaneousely pressed permit tomove the selected cursor and consequently to modify the data range.

Q: Can I fit a plot curve using my own function?

A: Go to the Analysis menu and select the The Fit Wizard... command. Define the function (myFunction=...), enter the initialguesses for the parameters, choose the fitting range and the number of iterations and click ’OK’

Q: How can I visualize a pixel line profile from an image?

A: Right click on the image you want to analyse and select the option ’View pixel line profile’ from the popup menu. A dialogwindow opens and allows you to select the number of pixels used for the analysis. Choose a value and click "OK". Then clickon the image to select the start point and move your mouse to select an end point while keeping the left button pressed. Whenyou release the left button a plot window appears, representing the pixel intensity versus pixel index.

Q: How can I make a graph that has one x-axis, but two y-axes with different orders of magnitude?

A: Select at least two columns that you want to display and use the Double-Y.

The QtiPlot Handbook 319 / 319

Chapter 9

Index

EExcel, 4, 6

Ggraph, 4

Mmatrix, 4, 8, 199, 200

Ttable, 4, 5, 197, 198, 217, 218