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Overlay Points or County boundaries on maps

Posted: Wed Mar 30, 2005 1:42 pm
by andyg
I was wondering if it is possible to overlay counties and/or "points" (i.e., cities) on a saved map?

If not would it be possible to add it to the "wish-list"

Posted: Thu Mar 31, 2005 12:52 pm
by jkrob
PCGRIDDS32 does not have that capability at this time. The way that the geopolitical & lat/lon lines are drawn is there is a file (world.dat, usa.dat. alaska.dat, etc) which has a list of points defined by lat/lon positions on the earth. When the time comes to create a base map, the code figures out how much area will be displayed on the screen and at what grid projection. It then goes through that map file and searches for any point which falls within that view. It then plays "connect-the-dots" and draws the map.

If the county, highway, city information were available in the format PCGRIDDS32 would need, it would be no problem to incorporate it into program. I really don't have the time to do something like that longhand.

Also, for international users, it would be a real bear to impliment something like that on a global scale...but it could be done...with the proper resources.

However, something I do need to impliment is a global land elevation file. There are several diagnostic calculations and future improvements which reference a surface at a fixed height above the ground.

Thanks,
Jeff