Re: Processing Large Memory arrays in Octave under WinXP 32bit

[Jordi Gutiérrez Hermoso]

On 11 February 2010 09:41, Journeaux, Ian <address@hidden> wrote:
> To simplify the troubleshooting I reduced the problem down to
>
>
>
> a(3000,3000) = 0;
>
> b=imrotate(a,5);

You begin by allocating a rather large matrix that takes up about 69
megabytes in RAM. It appears that the imrotate algorithm takes this
large matrix and uses temporary workspace that eats up all the memory.
Testing on my machine, it seemed to use close to 1.5 gigs of RAM.
Although this should fit in your physical memory, this is contingent
on the rest of your OS not occupying this memory and memory
fragmentation may also make it impossible to allocate the necessary
workspace necessary.

I am not sure if the imrotate algorithm can be optimised to use less
memory. At a glance, I couldn't see part of the code that could
obviously be optimised. Did you look at its code yourself?

- Jordi G. H.