pstricks coordinate limitation

[Michael J. Sharpe]

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Users of PSTricks more experienced than I have most likely run into the
following limitation on the size of coordinates. I just ran into it in
connection with a project (fun, not work) to use digital elevation data to
make a computed view from my office. I used Mathematica for the
computations and Tex with PSTricks for output formatting. The problem arose
when making a map of southern California indicating the locations
(color-coded by distance) of peaks on the skyline. The natural coordinates
are of course degrees, and longitude here is about 117 West. PSTricks
converts all coordinates to Tex dimen registers which leads to an absolute
upper bound of approximately 18 feet. With plotting at a scale of one
degree longitude =3 inches, the origin is at a distance of 117*1/4 ft,
which is close to 30 feet, and one is forced to prefilter all the input
data with a fixed offset to avoid the overflow.

What would be nice, should someone be thinking of updating PSTricks, is a
pair of new parameters, xoffset and yoffset, that if defined would be
subtracted from all coordinates before passing them to the dimension
registers, and which would be added after reading from the dimension
registers.

(In case anyone is curious, I posted the map in question to
http://delmath.ucsd.edu/plotskyline.pdf)

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