Subject:
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Re: New World LUG Map demo
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Newsgroups:
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lugnet.admin.general
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Date:
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Sat, 12 Apr 2003 15:50:18 GMT
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Viewed:
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719 times
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In lugnet.admin.general, Andrew Westrate writes:
> Todd,
> If you remember where you got the country data from, will you please post a
> link? I've been using data from Penn State's site:
> http://www.maproom.psu.edu/dcw/ but unfortunately that data is too high
> resolution to use for world maps. The resulting svg files end up being huge
> (several megs).
I'm almost positive it was from the GRID website in Geneva, Switzerland.
The files I downloaded are gnv029.zip (world city population database) and
gnv019.zip (world coastline data) if that helps. The map data is given in a
horribly designed and virtually undocumented ASCII dump/interchange format
that ESRI calls .e00 -- but after transformation into a useable intermediate
format, the GRID dataset actually works. It's fairly high resolution, however
-- weighing in at 3-4 megabytes -- completely unsuitable for web use -- so
before converting it to SVG, what I do is run it through an arc and polygon
simplification step on-the-fly to remove unnecessary detail. That brings the
SVG files, after compression, down to as little as 50KB, and I think I can even
get this down to 25KB with a little more work.
--Todd
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Message is in Reply To:
 | | Re: New World LUG Map demo
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| (...) (URL) Currently the program is pretty basic (it only supports ArcInfo Ungenerate files). I've copied the code and modified it a bit to do several different map projections. Todd, If you remember where you got the country data from, will you (...) (21 years ago, 30-Mar-03, to lugnet.admin.general)
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