Visual Storytelling with D3

Ritchie S. King is a reporter and visual journalist at FiveThirtyEight.com, focusing on data visualization and interactive features. He previously held a similar role at Quartz. In a previous life, he was a chemical engineer at a start-up trying to turn wood chips and switchgrass into fuel. Though he left engineering to become a journalist, he’s still into math and likes to muck with data. His written stories and graphics have appeared in the New York Times, Bloomberg Businessweek, Popular Science, and IEEE Spectrum.  

Foreword         xi

Preface         xiii

Acknowledgments         xvii

About the Author          xix



 

Chapter 1: Visual Storytelling and D3         1

Visualization, Visualized   1

Charts Give Data a Form–That Form Tells a Story   2

Quality: It Is All about Content   5

Design: It Is All about Form   6

Visual Storytelling   7

Enter D3   7

Things You Designers Will Love about D3   8

Things You Coders Will Love about D3   8

Things for Which You Should Not Use D3   9

Notes on Using D3   9

Tools You Will Need   10

Summary   10

 

Chapter 2: Finding a Data-Driven Story and Telling It Visually          11

Getting Started   11

Is the World Getting Older?   12

Finding and Inspecting Data   13

Honing the Concept   15

Choosing a Form   17

The Example We Will Build in This Book   27

Summary   29

 

Chapter 3: Scalable Vector Graphics            31

Peeking under the Hood   31

What Is SVG, Exactly?   31

Playing with Circles in SVG   32

Inspecting SVG in the Web Inspector   34

Styling SVG Elements with CSS   35

Other Shapes 37 

SVG Text   41

SVG Style Properties   44

Drawing Order and Groups   47

Transformations   49

Building a Bar Chart in SVG   51

Summary   64

 

Chapter 4: Shaping Web Pages with D3 Selections          65

Getting Set Up with D3   65

Making Selections   66

Changing a Selection’s Attributes   70

D3 Strives to be Declarative   74

Chaining Methods   74

Appending New Elements   77

Putting It All Together   79

Selecting Multiple Elements with d3.selectAll()   80

Building a Bar Chart with Selections   81

Summary   103

 

Chapter 5: Data-Joins: Enter          105

What Are Data-Joins?   105

A Conceptual Overview of Data-Joins: Enter   106

Enter and Binding Data   107

Using a Data-Join to Make a Bar Chart   111

Using Anonymous Functions to Access Bound Data   115

Finishing the Rest of the Chart   119

Storing Data in Objects   120

Summary   125

 

Chapter 6: Sizing Charts and Adding Axes          127

Linear Scales   127

Using Smart Margin Conventions   132

Adding Axes   135

Ordinal Scales and Axes   144

Summary   156

 

Chapter 7: Loading and Filtering External Data           157

Building a Graphic that Uses All of the Population Distribution Data   157

Data Formats You Can Use with D3   158

Creating a Server to Upload Your Data   159

D3’s Functions for Loading Data   160

Dealing with Asynchronous Requests   165

Loading and Filtering a Large(r) Data Set   171

Putting It All Together   173

Summary   175

 

Chapter 8: Making Charts Interactive and Animated         177

Data-Joins: Update and Exit   177

Interactive Buttons   181

Updating Charts   190

Adding Transitions   193

Using Keys   196

Summary   197

 

Chapter 9: Adding a Play Button         199

Wrapping the Update Phase in a Function   199

Adding a Play Button to the Page   203

Making the Play Button Go   204

Allowing the User to Interrupt the Play Sequence   207

Summary   213

 

Chapter 10: Striking Out on Your Own           215

This Book is a Foundation for Learning D3   215

How to Get Unstuck   215

Always Be Coding   217

Summary   218

 

Appendix A: JavaScript for Beginners         219

JavaScript in Brief   219

Your Browser’s JavaScript Console   219

Basic Math, Variables, and Data Types   220

Writing JavaScript in Markup and .js Files   223

Arrays and Objects   224

Methods and Functions   227

If Statements and for Loops   228

Debugging   232

 

Appendix B: Cleaning the Population Distribution Data          235

 

Index           255