Book Image

Learning D3.js 5 Mapping - Second Edition

By : Thomas Newton, Oscar Villarreal, Lars Verspohl
Book Image

Learning D3.js 5 Mapping - Second Edition

By: Thomas Newton, Oscar Villarreal, Lars Verspohl

Overview of this book

D3.js is a visualization library used for the creation and control of dynamic and interactive graphical forms. It is a library used to manipulate HTML and SVG documents as well as the Canvas element based on data. Using D3.js, developers can create interactive maps for the web, that look and feel beautiful. This book will show you how build and design maps with D3.js and gives you great insight into projections, colors, and the most appropriate types of map. The book begins by helping you set up all the tools necessary to build visualizations and maps. Then it covers obtaining geographic data, modifying it to your specific needs, visualizing it with augmented data using D3.js. It will further show you how to draw and map with the Canvas API and how to publish your visualization. By the end of this book, you'll be creating maps like the election maps and the kind of infographics you'll find on sites like the New York Times.
Table of Contents (13 chapters)
6
Finding and Working with Geographic Data

Value and use of the hexagon

Hexagons can solve some of the problems we mentioned in the preceding section. They can help the unequal area problems of choropleth maps and can bring ordered focus to point clusters. Let’s look at a few first:

Hexagonal tiling

As you can see, hexagons have equal length sides and fit nicely next to each other. However, they’re not just a pretty face, they also have properties we can leverage well in data visualization:

  • Hexagons divide a given area into equal-sized hexagons. This is called tiling and can also be done with other shapes such as circles, triangles, rectangles, or other polygons.
  • However, if you tile your wall with circles, you will end up with gaps between the circles. Covering a plane gap-free with repeating symmetric shapes is called a regular tessellation and is, in fact, only possible with squares, triangles, and hexagons...