GeoJSON and TopoJSON
Get introduced to the formats used to handle geographical information in D3.
We'll cover the following...
Another string to the bow of D3.js is the addition of a set of powerful routines for handling geographical information.
In the same sense that a line graph is a simple representation of data on a document, a map can be regarded as a set of points with an underlying coordinate system. When you say it like that, it seems obvious that it should be applied as a document ...