Chapter 12. Creating Maps with GeoJSON and TopoJSON
D3.js provides extensive capabilities for creating maps and to facilitate you in presenting data as part of the map or as an overlay. The functions for mapping within D3.js leverage a data format known as GeoJSON, a form of JSON that encodes geographic information.
Another common type of data for maps in D3.js is TopoJSON. TopoJSON is a more compressed form of GeoJSON. Both these formats are used to represent the cartographic information required to create a map, and D3.js processes this data and performs its usual magic of converting this information into SVG paths that visualize the map.
This chapter wills start with a brief overview of GeoJSON and TopoJSON. This will give you the foundation ...