Book Image

Data Visualization with D3 4.x Cookbook - Second Edition

By : Nick Zhu
Book Image

Data Visualization with D3 4.x Cookbook - Second Edition

By: Nick Zhu

Overview of this book

Master D3.js and create amazing visualizations with the Data Visualization with D3 4.x Cookbook. Written by professional data engineer Nick Zhu, this D3.js cookbook features over 65 recipes. ? Solve real-world visualization problems using D3.js practical recipes ? Understand D3 fundamentals ? Includes illustrations, ready-to-go code samples and pre-built chart recipes
Table of Contents (21 chapters)
Data Visualization with D3 4.x Cookbook - Second Edition
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Building a choropleth map


Choropleth map is a thematic map, in other words, a specially designed map not a general purpose one, which is designed to show measurement of statistical variable on the map using different color shades or patterns; or sometimes referred as geographic heat-map in simpler terms. We have already seen in the previous two recipes that geographic projection in D3 consists of a group of svg:path elements, therefore, they can be manipulated as any other svg elements including coloring. We will explore this feature in geo-projection and implement a Choropleth map in this recipe.

Getting ready

Open your local copy of the following file in your web browser hosted on your local HTTP server:

https://github.com/NickQiZhu/d3-cookbook-v2/blob/master/src/chapter12/choropleth.html.

How to do it...

In a choropleth map different geographic regions are colored according to their corresponding variables, in this case based on 2008 unemployment rate in US by county. Now, let's see how...