Wouldn't it be better in this case to use an MPIScatterV? ~A
On Mon, Sep 22, 2008 at 4:03 PM, Barry Smith <bsmith at mcs.anl.gov> wrote: > > I would only expect good performance if you used MPI calls to send the > blocks of rows of the matrix to the process > they belong to and use MatGetArray() to pass into the MPI_Recv to receive > the data into. > > Barry > > > On Sep 22, 2008, at 1:34 PM, Yujie wrote: > > Thank you for your reply, Matt. I have checked the tutorials. They just >> use specified values and MatSetValues() to make a parallel matrix. Now, the >> matrix I use is in a single node of the cluster. I have 'M' nodes in this >> cluster. I need to copy the sequential matrix to other 'M-1' nodes and then >> use MatSetValues() or I just use MatSetvalues() in the node where the matrix >> is? The latter should work, right? thanks. >> >> Yujie >> >> >> On Mon, Sep 22, 2008 at 11:09 AM, Matthew Knepley <knepley at gmail.com> >> wrote: >> The right way to do this is to input the matrix using MatSetValues() >> in a distribute fashion. You can consult any of the tutorials, for >> instance >> KSP ex2 for an example of this. >> >> Matt >> >> On Mon, Sep 22, 2008 at 12:57 PM, Yujie <recrusader at gmail.com> wrote: >> > Hi, Petsc developer >> > >> > Now, I have a sequential dense matrix. How to get a parallel matrix >> based on >> > it? thanks a lot. >> > >> > Regards, >> > >> > Yujie >> -- >> 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/20080922/be7afabe/attachment.htm>
