Map Demo

Where to get data?

Go Geography -> Maps & Data -> TIGER Products -> TIGER/Line Shape Files

http://www.census.gov/geo/maps-data/data/tiger-line.html

But it's not that easy. The population data comes with topography data, but it's not topography data you want to show. It's "real" boundries which doesn't include lake bounderies. And it doesn't have a decent mapping between states and counties.

Fortunately, the county boundries can also be downloaded separately.

Census data:
https://www2.census.gov/geo/tiger/TIGER2010DP1/
County_2010Census_DP1.zip

Topology data:
https://www.census.gov/geo/maps-data/data/cbf/cbf_counties.html
cb_2015_us_county_5m.zip

Download those files to "raw/data" and unzip them there.

Map the Data

bin/extractCounties

Filter/Reduce the Data

bin/reduceCounties

Filter/Reduce the Topography Data

bin/reduceTopography

What gets created?

Well, a bunch of raw "geojson" data gets generated under raw/geojson. That's temporary stuff. You can nuke it.

The displayable stuff ends up in public/data:

public/data/states.population.json - State population data
public/data/counties.population.json - County population data
public/data/counties - Topology data for the counties per states

There is one special file:

public/data/states.info.json