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Re: VARRAY, memory & extracting subarrays [message #25608 is a reply to message #25607]

Sun, 01 July 2001 22:10

Craig Markwardt
Messages: 1869
Registered: November 1996

Senior Member

Kristine Hensel <kristine@esands.com> writes:
> I'm processing large (105 MB) arrays of images, and I've been running
> into memory problems. (Not surprisingly, right?) I've started using
> Eric Korpela's VARRAY routine, which has helped, but I still can't
> manage to extract a subarray without using all of the available memory.
> Theoretically I have 1 GB of memory, and we've tried maximizing every
> system variable that we can, but I'm still crashing ("Unable to allocate
> memory to create array") when I try to run my image processing program.
...

VARRAY is a pretty extreme measure for your needs. Avoid it if you
can. [ Although I admit Korpela's routine is *very* cool! ]

1. Can you increase your swap space?
2. Have you checked your process limits (ie, "limit" or "ulimit"
command before running IDL)?
3. Big problem is that you say "sector_images = images", which deletes
the old mapping of sector_images. You can do this instead:
sector_images(*,*,*) = images ; or even better,
sector_images(0,0,0) = images ; which is faster but sneaky
4. Investigate chunking or banding.

Hope these help! I would really bet on number 2 though.
Craig

--
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Craig B. Markwardt, Ph.D. EMAIL: craigmnet@cow.physics.wisc.edu
Astrophysics, IDL, Finance, Derivatives | Remove "net" for better response
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[Message index]

		Re: VARRAY, memory & extracting subarrays By: Kristine Hensel on Mon, 02 July 2001 17:23
		Re: VARRAY, memory & extracting subarrays By: Richard French on Mon, 02 July 2001 05:29
		Re: VARRAY, memory & extracting subarrays By: Richard French on Mon, 02 July 2001 05:28
		Re: VARRAY, memory & extracting subarrays By: Richard French on Mon, 02 July 2001 05:27
		Re: VARRAY, memory & extracting subarrays By: Kristine Hensel on Mon, 02 July 2001 00:38
		Re: VARRAY, memory & extracting subarrays By: Craig Markwardt on Sun, 01 July 2001 22:10

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