topojson VS Data-Visualizations-Medium

GitHub also supports GeoJSON and it’s topology extension TopoJSON. Creating interactive maps could not have been simpler.

- https://github.com/topojson/topojson-specification

My guess is that Github just recognizes and supports previewing this particular spec.

This tutorial will show you how to convert publicly available shapefiles to TopoJSON to create interactive maps with d3/d3-geo. I will show you how to do this without the use of the command line so you can get into experimenting with d3 as fast as possible. If you are interested in working with shapefiles and TopoJSON in a more advanced fashion, I suggest you take a look at Mike Bostock’s recent multipart tutorials on command-line cartography.

The next chart in the series is a simple map of the world. In this chart Curran actually uses a Topojson file, then converts it into Geojson and then plots it. I am not planning to do that as it seems complicated and also for some reason the topojson library does not play nice with Node on my computer and I was too lazy to actually debug it 😬. So instead I are going to use a simple geojson I found on D3 Graph Gallery.

For the globe spinning, I used d3 and topojson to render the world at whatever projection/rotation/etc I give it. Then, using requestAnimationFrame, every frame I slightly rotate the world. Then the "water" behind it is just a blue circle that has hidden overflow.

This is Part 2 of a three-part series about creating visualizations for dissecting data and models. Part 1 can be found here and code, including a Jupyter Notebook with the visualizations in this post, is on GitHub.