comp.lang.idl-pvwave archive: archive » large arrays and transpose

Home » Public Forums » archive » large arrays and transpose

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

Re: large array [message #41246 is a reply to message #31350]

Wed, 13 October 2004 15:55

Dick Jackson
Messages: 347
Registered: August 1998

Senior Member

"Wolf Schweitzer" <shwi@irm.unizh.ch> wrote in message
news:416d54e2$1@idnews.unizh.ch...
>
> So, I figured that large files can not be read in a single read process,
> so I tried this:
>
> chunk=intarr (2000,2000,coupleofslices)
>
> imagearray = intarr (2000,2000,900) ;--- A HUGE ARRAY!!!!!
>
> ...
> point_lun, lun, ... long64(2000) * 2000 * slicecount
> ;-- position anywhere inside file using a L64 variable
>
> readu, chunk ;--- only read small portion into memory
>
> imagearray [*,*,slicecount:slicecount+coupleofslices-1] = chunk
>
> or
>
> imagearray [*,*, 0:coupleofslice-1] = chunk
> ...

It sounds like this approach is working for you, but I'll mention a tip
about this use of [*, *, ...]: I think you would be better off using [0, 0,
...] here, as discussed in these articles:

http://www.dfanning.com/misc_tips/submemory.html
http://www.dfanning.com/code_tips/asterisk.html

This could run you into trouble when working with big arrays!

Hope this helps.

Cheers,
--
-Dick

Dick Jackson / dick@d-jackson.com
D-Jackson Software Consulting / http://www.d-jackson.com
Calgary, Alberta, Canada / +1-403-242-7398 / Fax: 241-7392

Report message to a moderator

[Message index]

		large arrays and transpose By: Sean Raffuse on Mon, 01 July 2002 07:49
		Re: large array By: Dick Jackson on Wed, 13 October 2004 15:55
		Re: large array By: btt on Tue, 12 October 2004 10:35
		Re: large array By: Wolf Schweitzer on Wed, 13 October 2004 09:19
		Re: large array By: Dick Jackson on Tue, 12 October 2004 10:43

Previous Topic:	largest array, most memory accessible
Next Topic:	ecw IDL Reader

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Fri Oct 10 01:58:15 PDT 2025

Total time taken to generate the page: 0.16332 seconds