[EM] Shortest splitline maps with 2010 (2013) data

[Kristofer Munsterhjelm]

On 11/29/2016 12:24 AM, Raph Frank wrote:
> I wrote a quick implementation using the Hilbert space.  I think I have
> the point comparison correct.  It uses the center of the bounding box of
> the district as the middle of the Hilbert curve.
> 
> The largest curve goes top left to bottom left to bottom right to top right.
> 
> http://raphfrk.com/district/2010/html/index.html
> 
> It doesn't actually give contiguous districts, since the curve isn't
> restricted to the state boundary.

Ah, yes. I imagine it would be possible to warp the state into a square,
assign points, and then warp back, but I'm not sure if that would
preserve the approximation to optimality. I think it wouldn't cause too
great a distortion since how far you go along the path depends on the
population rather than on the length of the path, but I can't be
entirely certain.

According to Warren, the Sierpinski curve is better than the Hilbert one
as well, so it'd be interesting to see if it would produce better
results in practice. However, one'd probably have to solve the
non-contiguous problem first.