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"TRUE" map projections [message #3431]

Tue, 24 January 1995 13:34

afl
Messages: 51
Registered: December 1994

Member

How can one obtain (for example) a "true" Mercator map
projection in IDL? Sounds rather academic, doesn't it?
But in a given window if one issues

IDL> map_set, /merc, /cont, /grid, /usa, limit=[15,-130,50,-60]

vs.

IDL> map_set, /merc, /cont, /grid, /usa, limit=[15,-180,50,-30]

I guaranteee you the "shape" of the geographical boundaries
will be different. There must be a single, proper aspect ratio for
a map to be called a "true" Mercator projection. Is IDL capable
of producing "true" map projections, or is one able to arbitarily
re-shape the projection into any form he wishes such that the
specification of the projection is all but pointless? Does one
simply say "hmmmm, looks good to me" and move onto the next task?

--

Andrew F. Loughe email: afl@cdc.noaa.gov
University of Colorado, CIRES voice: (303) 492-0707
Campus Box 449 fax: (303) 497-7013
Boulder, CO 80309-0449 USA

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[Message index]

		"TRUE" map projections By: afl on Tue, 24 January 1995 13:34
		Re: "TRUE" map projections By: Serdar Manizade on Tue, 31 January 1995 05:54
		Re: "TRUE" map projections By: afl on Mon, 30 January 1995 14:54
		Re: "TRUE" map projections By: Serdar Manizade on Mon, 30 January 1995 11:33
		Re: "TRUE" map projections By: zawodny on Fri, 27 January 1995 09:32
		Re:"TRUE" map projections By: Serdar Manizade on Fri, 27 January 1995 08:00

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