comp.lang.idl-pvwave archive: archive » map_proj

Home » Public Forums » archive » map_proj_init

Show: Today's Messages :: Show Polls :: Message Navigator
E-mail to friend

Re: MAP_PROJ_INIT [message #78192 is a reply to message #53364]

Sat, 29 October 2011 07:18

David Fanning
Messages: 11724
Registered: August 2001

Senior Member

alx writes:

> In order to process some GPS data, I logically write:
> IDL> map = map_proj_init(101, ELLIPSOID=24, ZONE=31)
> wanting to use WGS84 ellipsoid and UTM projection (zone 31 is for
> Paris), for further use of the "map_proj_forward" function. Then :
> IDL> print, map.A, map.E2, map.PROJECTION
> 6370997.0 0.00000000 20
> shows that IDL rather chooses the SPHERE and the projection n°20.
> Moreover this projection is not referenced in the IDL_help, the
> projection index ranging from 0 to 19.
> Forcing GCTP keyword to 1 does not change anything.
> What does it mean ?

I doubt it means anything. At most it means IDL maintains
a different indexing scheme internally than they do in
their public interface. That's not unusual. I don't think
I would spend any time worrying about it. :-)

Cheers,

David

--
David Fanning, Ph.D.
Fanning Software Consulting, Inc.
Coyote's Guide to IDL Programming: http://www.idlcoyote.com/
Sepore ma de ni thui. ("Perhaps thou speakest truth.")

Report message to a moderator

[Message index]

		map_proj_init By: marit on Sat, 07 April 2007 15:09
		Re: MAP_PROJ_INIT By: David Fanning on Sat, 29 October 2011 11:41
		Re: MAP_PROJ_INIT By: lecacheux.alain on Sat, 29 October 2011 11:10
		Re: MAP_PROJ_INIT By: lecacheux.alain on Sat, 29 October 2011 10:14
		Re: MAP_PROJ_INIT By: David Fanning on Sat, 29 October 2011 09:48
		Re: MAP_PROJ_INIT By: lecacheux.alain on Sat, 29 October 2011 08:27
		Re: MAP_PROJ_INIT By: David Fanning on Sat, 29 October 2011 07:18

Previous Topic:	unable to set time attribute for netCDF in IDL
Next Topic:	ENVI Navigating GeoTiff Image Incorrectly?

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Wed Oct 08 17:12:18 PDT 2025

Total time taken to generate the page: 0.00420 seconds