On Fri, Sep 18, 2009 at 7:32 AM, Niall Moran <nmoran at thphys.nuim.ie> wrote:
> Matthew Knepley wrote: > >> On Thu, Sep 17, 2009 at 12:44 PM, Niall Moran <nmoran at >> thphys.nuim.ie<mailto: >> nmoran at thphys.nuim.ie>> wrote: >> >> Hi, >> >> I am just wondering if anything has changed on the status of this >> feature. Would be great to be able to perform matrix vector >> multiplications on complex Hermitian matrices by only providing >> one half of the matrix. >> >> >> It is not curently in the todo list since we have only had one request. It >> seems like it would just take being careful about the >> complex case for SBAIJ if you would like the try the implementation. We >> can answer questions. >> >> Thanks for you rapid response. I would be interested in attempting to > implement this for MPIAIJ if it would not be too involved. Would you be able > to sketch a rough outline of what this would involve? Would I need to just > modify the MatMult_MPIAIJ function or would I need to modify the creation of > the scatterers in MatAssemblyBegin_MPIAIJ? > > Could anyone suggest some documentation that describes how the matrix > vector multiplication works in petsc for MPIAIJ typed matrices? > > Does matrix vector multiplication with just the upper half work for real > symmetric matrices? > 1) Understand the SBAIJ implementation. This is used for real symmetric matrices 2) In the places where the lower triangle is retrieved, add a complex conjugation. Matt > Regards, > > Niall. > -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20090918/a5294d59/attachment.htm>