On 12 November 2011 18:18, Carlo de Falco <carlo.defa...@gmail.com> wrote: > > On 12 Nov 2011, at 16:04, c. wrote: > >> >> On 12 Nov 2011, at 12:17, Alexander Barth wrote: >> >>> Dear Filippone, >>> >>> Also an iterative parallel solver would be very useful for me. >>> Currently, I'm using either a direct solver (the \ operator) or the >>> conjugate gradient alogorithm. >>> I tried to find our more information about PSBLAS but it seems that >>> the web-page has currently some problems (time-out). >>> >>> Best regards, >>> Alex >> >> Alex, >> Most iterative solvers in Octave are implemented as m-files so if the new >> matrix >> class overloads matrix/vector multiplication they should be already usable >> with the new class ... >> Have you tried that already? I'm trying to install the package right now to >> check. >> c. > > It looks like it's working: > >>> n = 1000; >>> A = 15 * eye (n) + sprandn (n, n, .2); >>> b = ones (n, 1); >>> P = diag (diag (A)); >>> tic, [x, flag] = gmres (A, b, [], 1e-7, n, P); toc > Elapsed time is 1.73299 seconds. >>> As = sparsersb (A); >>> tic, [x, flag] = gmres (As, b, [], 1e-7, n, P); toc > Elapsed time is 1.40307 seconds. > > the speed-up is nothing to write home about though but, still, > it's a really nice package and already usable, > so Michele keep up with the good work :)
That's a tiny sparse matrix. I'm curious about how the algorithm scales. Can you try a couple of orders of magnitude larger? Also, what version of Octave is that? Are you working on dev or stable? - Jordi G. H. ------------------------------------------------------------------------------ RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 _______________________________________________ Octave-dev mailing list Octave-dev@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/octave-dev
