RE: error: memory exhausted or requested size too large for range of Octave's index type --

[William Krekeler]

-----Original Message-----
From: Martin Helm [mailto:address@hidden 
Sent: Wednesday, March 16, 2011 8:42 AM
To: William Krekeler
Cc: address@hidden
Subject: Re: error: memory exhausted or requested size too large for range of 
Octave's index type --

Am Mittwoch, 16. März 2011, 14:33:25 schrieb William Krekeler:
> -----Original Message-----
> I have 12 GB memory in a 64 bit windows 7 OS, Octave binary build 3.2.4. I
> can confirm that you can not build a matrix that large in Windows.
> 
> x = zeros( 25000,25000,'double');
>       error: memory exhausted or requested size too large for range of 
> Octave's
> index type -- trying to return to prompt
> 
> Largest successful array is interestingly only 13000x13000
> 
> Attr Name        Size                     Bytes  Class
>  ==== ====        ====                     =====  =====
>       x       13000x13000             1352000000  double
> 
> This has something to do with how Octave (or programs in general)
> interfaces with Windows memory management. I know that newer versions, I'm
> using win7, pre-allocate memory and 'lock' it out even though it
> technically isn't in use. The 'lock' preloads commonly used programs to
> allow for faster access. The memory is not truly locked because (while
> running similar background programs) I can create at least a 48000x45000
> double variable in that other program (ML) on the same machine.
> 
> Bill Krekeler

Thank you for that information, it is good to know. Is there any chance for 
you to check if octave 3.4 behaves the same on a 64 bit windows as your 3.2.4 
did or if 3.4 is able to handle that large matrices like it does on linux?
(Not sure if 3.4 is available for windows?)


Martin,

Sorry for the slow response. I've been off work for a few days helping with 
FIRST, (http://www.usfirst.org). I would be glad to check memory status in 3.4, 
but the windows binary is not at 3.4. As I understand it is not easy to compile 
octave in windows. I tried using cygwin octave which is at 3.4, but it presents 
even more stringent memory requirements. I couldn't even create a 13000x13000 
double in octave cygwin.

Bill