On Fri, Sep 18, 2009 at 8:48 AM, Hong Zhang <hzhang at mcs.anl.gov> wrote:
> > Should we create a new matrix type, say hbaij, > for operations of Hermitian matrices? > No, it should be a minor perturbation. Matt > Hong > > > On Fri, 18 Sep 2009, Matthew Knepley wrote: > > 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 >> >> -- 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/b4916301/attachment.htm>
