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Re: Getting ROI data from an image [message #77853]

Mon, 03 October 2011 06:15

Rebecca
Messages: 4
Registered: October 2011

Junior Member

OK, thanks for the help on understanding IDL's subscripting!

On Sep 30, 5:32 pm, David Fanning <n...@dfanning.com> wrote:
> Rebecca writes:
>> That's great, and it makes so much sense, but it doesn't seem like IDL
>> obeys those laws of indexing. Using
>> temp = img[x,y,*]
>> produces an out of memory error. It's not hard to figure out why-
>> temp = img[x,y,0]
>> Produces a [npix, npix] array, where npix is the number of pixels
>> referenced in 'indices'. What I was expecting to happen was a [npix]
>> vector! IDL is playing by different rules here.
>
>> npix = N_ELEMENTS(indices)
>> z = INTARR(npix)
>> temp = img[x,y,z]
>
>> That produces the magical vector array I want. So, is there any way to
>> play by these rules and grab 300 bands worth of data at once so I have
>> a [npix, bands] array? Or should I give up the chase and just FOR loop
>> it?
>
> Actually, you are doing this correctly by making
> your own index vector. See the latter half of
> this article:
>
> http://www.idlcoyote.com/misc_tips/submemory.html
>
> 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.")

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[Message index]

		Re: Getting ROI data from an image By: Rebecca on Mon, 03 October 2011 06:15
		Re: Getting ROI data from an image By: David Fanning on Fri, 30 September 2011 14:32
		Re: Getting ROI data from an image By: Rebecca on Fri, 30 September 2011 14:16
		Re: Getting ROI data from an image By: David Fanning on Fri, 30 September 2011 13:41
		Re: Getting ROI data from an image By: Rebecca on Fri, 30 September 2011 12:41
		Re: Getting ROI data from an image By: David Fanning on Fri, 30 September 2011 12:19
		Re: Getting ROI data from an image By: Brian Daniel on Fri, 30 September 2011 11:42

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