Re: Help me something about GNU Octave

[novakyu]

On Jan 17, 2008 6:22 PM, Johann Cohen-Tanugi <address@hidden> 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

My first guess would be that the error message is correct. You ran out
of memory in the "rand(10000,10000)" command. I am not a real
programmer, so I'm not very familiar with technical details, but
simple counting tells me: each single precision number takes 4 bytes,
and you requested 10000*10000 of such numbers: 400 000 000 bytes,
which work out to: 381.5 MB. If you have 1GB or less, accounting for
all memory usage by other programs and very likely overheads, you
should run out of memory.

It's even worse if rand uses double precision numbers.

Regards,

Andrzej