Generating shaded maps of India with state-level data series.

March 23, 2008 4:31 PM

What's the easiest way of generating a map similar to this? I have several state-level data series I want to display on maps of India.

I assume this blank map of India in SVG format is a good starting-point. Now, what program(s) do I use to link areas on the map to my data series and hence automatically shade states by a variable x?

My data looks like:
[state code] state x
[jm] jam 1.93386
[hp] him 1.74945
[pj] pun 1.90247
[uc] utt 2.13038
... 33 more states ...

I have Windows, Stata, Excel and zero budget.

posted by matthewr to computers & internet (6 comments total)

I would place my first bet on R.
posted by ROU_Xenophobe at 4:56 PM on March 23

A search term for you: Choropleth map.
The easiest way? With GIS software. You have zero budget, and my only experience is with ArcGIS software, which ain't free. You might investigate whether an institution that you have access to has a license for GIS software, or else investigate the various free/open source GIS programs. I'm not familiar with .svg format, except that it's a vector image format, so I don't know offhand whether it will be useful. What you need out of your base map is a vector file with separate polygons for each state. Polylines will not be fun to try and make a choropleth map from.
posted by agentofselection at 5:10 PM on March 23

My fist suggestion would be GIS software too, but ArcGIS is a long way from free. If you're feeling brave, you could delve into Grass which is available for Windows but has a pretty steep learning curve.

Another thing to look at: GE Graph for Google Earth. I've never used this, but it look to be able to colour polygons based on input data from Excel.
posted by Jimbob at 5:38 PM on March 23

(GE Graph may not import your SVG files directly, but if you look at the bottom of that page they give example polygon files, that are just a list of comma-separated coordinates, so assuming your SVG files are in lat/long format, you should be able to convert them yourself with a bit of effort.)
posted by Jimbob at 5:41 PM on March 23

Yeah SVG won't be imported correctly into just about any GIS program. You would be better getting the state data in a SHP format ideally.

For free software - even easier than GRASS is a simple GIS called MapMaker. Even someone with very little knowledge of GIS can get up to speed in about 2 weeks and produce some really great maps. Read the documentation and play around for a few weeks and you should be set.
posted by bigmusic at 5:48 PM on March 23 [1 favorite]

Looks like ArcGIS is what I want, then. My university computing service has a license for ArcGIS, so I should be able to use that.

I found some state- and, even better, district-level SHP files here, so it looks like I'm all set. Thanks!
posted by matthewr at 6:25 PM on March 23