Geospatial Mapping with D3

GeoJSON Is a format for enconding geographical data (...) can represent cities, countries and roads.

TopoJSON Is an extension of GeoJSON.

D3 Uses TopoJSON with the help of the client library.

Projections Define how geographical data is represent on a flat surface.

Choropleths

• Maps Areas are shaded
• Color proportional to the value being measured
• Visualization for quantitative and qualitative data

need to install

npm install -g topojson

create topo.json file

geo2topo custom.geo.json > custom.topo.json