Re: matrix operation in Octave

[Jordi Gutiérrez Hermoso]

On 30 March 2011 15:08, Akos Marton <address@hidden> wrote:
> We would like to get information from Octave -,maintainers ,-developers: how
> to get the Octave's programming-interface and/or shell-interface to use
> together with our implementation.

I'm not sure if this is a satisfying answer, but Octave, like Matlab,
to a first approximation is not much more than a glorified wrapper of
Fortran libraries. Octave doesn't implement low-level matrix
operations nor even slightly higher-level operations like SVD. It
relies on well-known free libraries to do that. In the former case, it
uses BLAS, and it's in fact possible to compile Octave with several
different BLAS implementations. The SVD code is usually taken from
LAPACK (I want to say "always", but I'm not sure if it's possible to
use a different library for it).

So what exactly do you need? If you need to compare your matrix
multiplication method with some BLAS implementation, it would probably
be better to directly call that BLAS implementation without going
through Octave. Same for LAPACK.

If you want to see for example how Octave calls your BLAS
implementation, you can see an example for matrix multiplication here:

     http://hg.savannah.gnu.org/hgweb/octave/file/tip/liboctave/dMatrix.cc#l2624

HTH,
- Jordi G. H.