Re: Map_set limits [message #10397 is a reply to message #10389] |
Tue, 25 November 1997 00:00  |
davidf
Messages: 2866 Registered: September 1996
|
Senior Member |
|
|
St�phane Erard (Erard@ias.fr) writes:
> I was trying to superimpose satellite images to a map in IDL 4, and had a
> problem:
>
> I have to set the map's dimensions to the image's to get a good match,
> using the keyword "position" in map_set.
> After several tries I found out that the map limits are enlarged by 2% in
> both directions (long/lat), while the dimensions are unchanged. The result
> is that I get a map of a larger area in the dimensions of my image.
Unfortunately, IDL's map projection routines are not designed
to put a map projection on an image. (I am, however, sympathetic
to the argument that they *should* be.) Rather, they are
designed to put an image on a map projection.
The proper sequence of commands to display an image that
corresponds to the limits in the variable "mapLimits" might
look something like this:
Map_Set, /Cylindrical, Limits=mapLimits
warpedImage = Map_Image(image, xloc, yloc, xsize, ysize)
TV, warpedImage, xloc, yloc, XSize=xsize, YSize=ysize
Map_Grid
Map_Continents
Cheers,
David
-----------------------------------------------------------
David Fanning, Ph.D.
Fanning Software Consulting
E-Mail: davidf@dfanning.com
Phone: 970-221-0438
Coyote's Guide to IDL Programming: http://www.dfanning.com/
|
|
|