comp.lang.idl-pvwave archive: archive » Re: Can this be done using CALL

Home » Public Forums » archive » Re: Can this be done using CALL_FUNCTION?

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

Re: Can this be done using CALL_FUNCTION? [message #19366 is a reply to message #19335]

Tue, 07 March 2000 00:00

John-David T. Smith is currently offline

John-David T. Smith
Messages: 384
Registered: January 2000

Senior Member

edward.s.meinel@aero.org wrote:
>
> OK, here's one for the IDL gurus (since I'm only a little guru would
> that make me a gu-gu?)...
>
> I am working with spectral images. Unfortunately, IDL is geared toward
> multidimensional data in which all of the dimensions are the same type
> (i.e. spatial, spectral, frequency...) but it doesn't like to operate on
> data with mixed dimensions, such as a multispectral image (unless I'm
> missing something really obvious).
>

What is it about multi-spectral data that IDL doesn't like? It certainly
doesn't care about whether a single dimension of your data array represents
spatial, temporal, or spectral changes... maybe I'm missing something. The IDL
data types are tied to machine types: longs, shorts, floats, doubles, etc...
mixing these types in a single array *is* impossible.

E.g., a 4-d array of floats in which axes 1 & 2 are spatial (e.g. latitide and
longitude), axis 3 is spectral (say 10 different bands), and axis 4 is temporal
(100 days worth of data at once per day) is perfectly acceptable. It's up to
you to keep track of which dimensions are which, but I don't see the problem...
It is true that certain IDL routines operate on images, or require other
specially formatted or dimensioned data, but how is it to know which dimensions
you are interested in without specifically telling it?

Maybe you could give us an example in which this kind of generality would be
useful.

JD

--
J.D. Smith |*| WORK: (607) 255-5842
Cornell University Dept. of Astronomy |*| (607) 255-6263
304 Space Sciences Bldg. |*| FAX: (607) 255-5875
Ithaca, NY 14853 |*|

Report message to a moderator

[Message index]

		Re: Can this be done using CALL_FUNCTION? By: davidf on Thu, 09 March 2000 00:00
		Re: Can this be done using CALL_FUNCTION? By: Struan Gray on Thu, 09 March 2000 00:00
		Re: Can this be done using CALL_FUNCTION? By: davidf on Thu, 09 March 2000 00:00
		Re: Can this be done using CALL_FUNCTION? By: edward.s.meinel on Thu, 09 March 2000 00:00
		Re: Can this be done using CALL_FUNCTION? By: davidf on Wed, 08 March 2000 00:00
		Re: Can this be done using CALL_FUNCTION? By: Struan Gray on Wed, 08 March 2000 00:00
		Re: Can this be done using CALL_FUNCTION? By: John-David T. Smith on Wed, 08 March 2000 00:00
		Re: Can this be done using CALL_FUNCTION? By: edward.s.meinel on Wed, 08 March 2000 00:00
		Re: Can this be done using CALL_FUNCTION? By: John-David T. Smith on Tue, 07 March 2000 00:00
		Re: Can this be done using CALL_FUNCTION? By: Martin Schultz on Tue, 07 March 2000 00:00

Previous Topic:	Converting 8-bit image + pallete to 24 bit image with alpha channel
Next Topic:	silly font problem

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Fri Oct 10 16:25:57 PDT 2025

Total time taken to generate the page: 0.39991 seconds