Re: Help me something about GNU Octave

[Ben Abbott]

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