Re: Help me something about GNU Octave

[Dmitri A. Sergatskov]

On Jan 17, 2008 9:30 PM, Ben Abbott <address@hidden> wrote:
>
> On Jan 17, 2008, at 9:22 PM, Johann Cohen-Tanugi wrote:
>
> > hello,
> > by sheer curiosity I gave a shot to this command :
> >
> >  [u, s, v] = svd (rand (10000, 10000));
> > and I actually get :
> > octave:1> [u, s, v] = svd (rand (10000, 10000));
> > error: memory exhausted or requested size too large for range of
> > Octave's index type -- trying to return to prompt
> >
> > any idea what could go wrong?  am on a linux FC7 laptop, and octve
> > is built from cvs source :
> > octave:2> version
> > ans = 3.0.0+
> >
> > best,
> > J.
>
> My RAM is maxed out, and I get the same thing with Matlab (4GB on
> 2.4GHz, core 2 Duo).
>
>  >>  [u, s, v] = svd (rand (10000, 10000));
> ??? Error using ==> svd
> Out of memory. Type HELP MEMORY for your options.
>
> Notice that memory requirements for the random arrays is 1.6GB, which
> is very close to the 2G available to each core.
>
>         10,000 * 10,000 * 16 = 1,600,000,000 bytes.
>
> I'm sure that svd will require some working space to do its job, not
> to mention that octave, linux, and any other apps you have running
> will need some memory as well.
>
> Ben
>

I guess the problem is that you need a _continuous_ chunk of memory that big...
The situation should be better on 64-bit platform.

Sincerely,

Dmitri.
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