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The Story

The following is taken from a post at a web forum soon after creating the cartogram visualization of Election 2004:

...why on earth did I do this ? It's really a combination of interest and opportunity. I am a computational geometer, and the problem of computing a cartogram for a map (where the weight function could be population, income levels, disease prevalence, what have you) is an interesting challenge, mainly because of the problems I described above. When I saw the electoral maps, I was reminded of work that that colleagues have done, and asked them for their data (hence the opportunity). it seemed like an interesting exercise in practical applications of geometry.
My starting point for this page was Robert Vanderbei's purple map representing the vote count (at a county level) in Election 2004 for Bush (red) and Kerry (blue). People had asked him (and I had wondered as well), whether the map could be represented as a cartogram, where each county was distorted to represent its true population, so as to make a more representative picture. Fortunately, I have colleagues who work on cartograms (more on this in the Credits), and was able to use their cartogram to create an equivalent purple map. Here's the FAQ:


Update: Nov 7, 2004

Garstner, Shalizi and Newman have another cartogram rendition of the vote:

They also had a histogram of county-level vote-shares, that had some anomalous values, and was therefore removed. The picture below is a similar histogram that I generated from the vote results.

And now for the maps...

In the maps below, B = fraction of vote Bush got, K = fraction Kerry got, and T is the third-party vote (almost always negligible). The color scheme is expressed in these terms. both raw PPM files are GIF files are linked; be warned that the PPM files are very large.