Post on 01-Nov-2014
description
D3 for Data Visualization onDesktops, Smart Phones, and Google Glass
SVCC (10/05/2013)Foothill College Los AltosOswald Campesatooswald@swiftbot.comocampesato@yahoo.com
Pace and Sequence of Topics This session moves quickly
Focus is primarily on demos
topics are discussed based on their relevance in demos (i.e., not necessarily sequential)
Some code will be made available later
Our Hat for Work-Related Topics:
Our Hat for Fun-Related Topics:
How/Where do the Demos Work? All demos work on desktop/laptops:launched as HTML5 Web pages
Demos created as Android apks work on:mobile phones, tablets, and Google Glass
• Android apks can be created via:Eclipse/PhoneGap/Android Studio/other
What is D3? open source project (2010) Mike Bostock (principal/creator) based on JavaScript a layer of "abstraction" over SVG also support for HTML5 Canvas github.com/mbostock/d3 https://github.com/mbostock/d3/
wiki/Gallery
Why/When use D3? data visualization extremely versatile leverage JavaScript skills leverage SVG Create HTML5 Web pages with D3 and:HTML5 Canvas, CSS3, SVG, jQuery, …
What Can D3 Do?
All the stuff you can do in SVG graphics/animation filters/gradients mouse/keyboard events custom charts/graphs Support for Ajax, JSON, XML, CSV files
How Does D3 Work?
Creates SVG elements via JavaScript
Often involves “method chaining”:svg.selectAll() .attr(a, “b”) .attr(c,”d”)…
select-data-enter-append: "TMCIID3” ("The Most Common Idiom in D3”)
Simple D3 Example<head> <script src="d3.min.js"></script><script> d3.select("body") .append("p") .text("Hello1 D3");</script><body> <p>Hello1 D3</p></body>
Adding SVG: General Approach
#1: create/append an <svg> element to <body>
#2: often define JavaScript array(s) of values #3: iterate through arrays create SVG elements: use constants/variables/anonymous functions
Optional: #4: add event listener(s) #5: add animation-related code
Creating a Circle in D3 (part 1)
1) First create an <svg> element:var svg = d3.select("body") .append("svg") .attr("width", width) .attr("height",height);
Creating a Circle in D3 (part 2)
2) Include the following D3 code:svg.append("circle") .attr("cx", 10) .attr("cy", 10) .attr("r", 100) .attr("fill", "red")D3 code generates this SVG element:<body> <circle cx="10" cy="10” r="100" fill="red" /></body>
A Scatter Chart (part 1)
Step #1 define a JS array with data values:var dataXValues=[10, 50, 20, 80,150,180,220];
Step #2 Create an SVG element: var svg = d3.select("body") .append("svg") .attr("width", width) .attr("height", height);
A Scatter Chart (part 2)Step 3 create and append circles: var circles = svg.selectAll("circles") .data(dataXValues) .enter() .append("circle") .attr("cx", function(d, i) { return (d*5*Math.random()); }) .attr("cy", function(d, i) { return (d*5*Math.random()); }) .attr("r", radius).style("fill", "red");
Using Arrays for all Circle Attributes
var generalizedCircles = svg.selectAll("circles") .data(dataXValues).enter().append("circle") .attr("cx", function(d, i) { return d; }) .attr("cy", function(d, i) { return dataYValues[i]; }) .attr(”r", function(d, i) { return dataRValues[i]; }) .style (”fill", function(d, i) { return dataFValues[i];})
Using Arrays for Rectangle Attributes
var generalizedRectangles = svg.selectAll(”rect") .data(dataXValues).enter().append(”rect") .attr(“x", function(d, i) { return dataXValues[i]; }) .attr(“y", function(d, i) { return dataYValues[i]; }) .attr(”width", function(d, i) { return dataWValues[i]; }) .attr(”height", function(d, i) { return dataHValues[i]; }) .style (”fill", function(d, i) { return dataFValues[i]; })
Mouse Handler for ScatterChartcircles.on("mouseover",function() { d3.select(this) // the “mouseover” circle .transition() .duration(duration) .attr("transform", function() { var sx = 1+Math.random(); var sy = 1-Math.random(); return "scale("+sx+","+sy+")"; }) })
Examples of Transforms in D3
yourPreviouslyCreatedElement .attr("transform", "translate(50,100)") .attr("transform", "rotate(40)") .attr("transform", "scale(0.5,1.3)") .attr("transform", "skewX(20)")
Easing Functions (Animation Effects)
Create an SVG element and append this code:.on("mouseover",function(){ .duration(1000) .delay(200) .ease("out-elastic",1,1)})
At least 10 easing functions available
Bar Charts in D3 Scale horizontal/vertical values
Various label types (numeric/date) for axes
Unicode support
Add mouse events to ‘bar’ elements
D3 and SVG Filters
Define an SVG <filter> element (in <defs>):<defs>…<filter id="blurFilter1”> <feGaussianBlur "stdDeviation"=4> </feGaussianBlur></filter>…</defs>
How to Define Filters in D3
var defs = svg.append("defs")defs.append("svg:filter") .attr("id", "blurFilter1") .append("svg:feGaussianBlur") .attr("stdDeviation", 4);
The preceding code is equivalent to this code:<filter id="blurFilter1”> <feGaussianBlur "stdDeviation"=4 /></filter>
D3 and SVG Linear Gradients
Insert this code in an SVG <defs> element:<linearGradient id="GradientL" gradientUnits="userSpaceOnUse" cx="100" cy="50" r="160" fx="100" fy="50"> <stop offset="0%" stop-color="red"/> <stop offset="33%" stop-color="blue"/> <stop offset="67%" stop-color="red"/> <stop offset="100%" stop-color="blue"/></linearGradient>
D3 Linear Gradients var gradientL = defsElement .append("svg:linearGradient") .attr("id", "GradientL") .attr("x1", "0%") .attr("y1", "0%") .attr("x2", "100%") .attr("y2", "100%") .attr("gradientUnits", "userSpaceOnUs”) Append-stop-colors…
D3 and SVG <pattern> Elements
Insert in the SVG <defs> element:<pattern id="checkerPattern" width="40" height="40" patternUnits="userSpaceOnUse”> <rect fill="url(#gradientDefinition1)" x="0" y="0" width="40" height="40"/></pattern>
D3 code for an SVG pattern: exercise
SVG and Maps
Election maps for presidential race: ABC: Raphaël/SVG Washington Post: Leaflet/SVG+HTML Politico: Raphaël/SVG NYT: Custom? Canvas/HTML RealClearPolitics: Raphaël/SVG FoxNews: Raphaël/SVG MSNBC: Raphaël/SVG Google: PolyGonzo/Canvas HuffingtonPost: Raphaël/SVG BBC: Raphaël/SVG
D3 APIs/Extensions/Plugins
Choropleth Maps (stereographic projection/others) Force diagrams
Extensions/plugins: RickShaw CS Extensions: Cubed
D3 and CSV Files
Read data from a CSV file (1,000 rows) Each row represents a line segment Add a mouseover event listener Append line coordinates to a second
array when users ‘mouse over’ that segment
Works fine for up to 4,000 rows
What about Large Datasets?
Superconductor.js: DSL/JS/Web WorkersUses a <canvas> element“browser in a browser”Smoothly handles 100K data points
• Druid (Metamarkets)• Weave/Yarn (Apache): layer over Hadoop• Kafka, Storm, and D3 (more recent)
D3 and Other Technologies
D3 and BackboneJS in one Web page
D3 and AngularJS in one Web Page
Use D3 with HTML5 Web Sockets
D3 with NodeJS (and Meteor)
D3 and CSS3
CSS3 2D transforms:rotate, scale, skew, translate, matrix, and perspective
• CSS3 3D transforms:Similar to 2D versions (but no ‘skew’)Also three axis-specific methods:rotateX, rotateY, rotateZ
• More details in next session
Spherical Coordinates
(1) x = w*cos(a); y = w*sin(a); (2) z = r*sin(b); (3) w = r*cos(b);
Substitute (3) into (1) to get: (4) x = r*cos(b)*cos(a); (5) y = r*sin(b)*sin(a); (6) z = r*cos(b);
D3 and Android
1) Create an Android application Test2) modify $TOP/res/layout/activity_main.xml: insert a WebView component 3) create $TOP/assets/www 4) copy TestD3.html into $TOP/assets/www5) modify src/com/Test.java: reference TestD3.html in onCreate()
Contents of main.xml
<?xml version="1.0" encoding="utf-8"?>
<WebView xmlns:android="http://….” android:id="@+id/webview" android:layout_width="fill_parent" android:layout_height="fill_parent" />
Contents of onCreate() Methodsuper.onCreate(savedInstanceState);setContentView(R.layout.activity_main);
Your new code goes here:mWebView = (WebView) findViewById(R.id.webview);mWebView.getSettings().setJavaScriptEnabled(true);
mWebView.getSettings().setDomStorageEnabled(true);
mWebView.loadUrl( "file:///android_asset/www/Test3D.html");
What is PhoneGap? A Plugin to create Hybrid Mobile apps Available on 6 platforms A JavaScript “bridge” Access to hardware (camera/etc) No compilation required No Java/Objective-C code Handles the manual steps for you Creates an index.html Web page
Why use PhoneGap?
No compilation required
No Java/Objective-C code
Handles the manual steps for you
Provides access to hardware (camera/etc)
D3 and Google Glass Create an Android apk in Eclipse
Deploy to Glass:adb install D3Demo.apk
• Find the package and main Android Activity:Let’s call them “a.b.c” and “D3Main”
* Launch from the command line:adb shell am start -a android.intent.action.MAIN -n a.b.c/.D3Demo
D3 Resources
online forums (Google group)
meetups in BA
Stackoverflow
code.google.come/p/d3-graphics
25 JavaScript Visualization Libraries
http://www.ma-no.org/en/content/index_visualize-your-data-25-javascript-visualization-libraries_1796.php
Open Source Projects
• Graphics Projects on http://code.google.com/p:+ css3-graphics and html5-canvas-graphics+ css3-jquery-graphics and d3-graphics+ svg-graphics and svg-filters-graphics+ easel-graphics, fabric-graphics, paper-graphics + ThreeJS, jQuery, Raphael, Google Go, Android+ Dart, Dojo, JSF, Two.js, JavaFX 2.0+ Lua, PHP, Perl, Python, Ruby, SWT graphics
Some Training Topics• D3/SVG
• HTML5 (CSS3/Canvas/etc)
jQuery/jQuery Mobile
Android (iOS later)
BackboneJS/PhoneGap
Recent/Upcoming Books
1) HTML5 Canvas and CSS3 Graphics (2012)2) jQuery, CSS3, and HTML5 for Mobile (2013)3) HTML5 Pocket Primer (2013)4) jQuery Pocket Primer (2013)5) HTML5 Mobile Pocket Primer (2014)6) D3 Pocket Primer (2014)
• “WebGL: Up and Running” (Tony Parisi)Co-creator of VRML and X3D