comp.lang.idl-pvwave archive - RDF feed
type: channel
description: Messages from Usenet group comp.lang.idl-pvwave, compiled by Paulo Penteado
items: How to expand large arrays?

How to expand large arrays?
type: item
description: I am trying to read in a large but unknown amount of data, and am getting (IDL 3.6.1 VMS and Windows) 'unable to allocate core' crashes long before I should be out of memory. Is there something that causes IDL to allocate something like 5x the size of the array being used? I understand that a temporary array is created, but I thought this would limit me to an array 1/2 the size of the available memory. I create a large array and expand it by either concatenation or by creation of a new array and pasting. In both instances, I crash when using 1/5 of my memory quota and less than half the physical memory available (according to IDL help,/memory. The respective operating systems say I'm at the limit of both physical and virtual). Yes, I created enough huge images to use my expected quota - got just the numbers I expected. Can anybody tell me what is going on, and how can I create an array that is large but nowhere near the quota? The two methods I tried were: temp=(~10000,2) data=[temporary(data),temp] and temp=fltarr(npts+10000,2) temp(0,0)=data data=temp temp=0 Both crashed when the IDL-reported memory usage was 9MB of my 50 MB VMS quota (VMS said I was using all 50MB). Thanks, Art Croucher Johns Hopkins Applied Physics Lab art.croucher@jhuapl.edu
creator: art.croucher
date: 1995-04-18T07:00:00-00:00