On Mon, Jul 9, 2018 at 10:02 PM Marius Buerkle <mbuer...@web.de> wrote:
> MatGetSubmatrix is in the current PETSc released called > MatCreateSubmatrix. Is this correct ? > Yep. I am old and cannot follow API changes anymore. Matt > On Mon, Jul 9, 2018 at 8:38 PM Marius Buerkle <mbuer...@web.de> wrote: > >> I see. What I want to do is to calculate the matrix product C=A*B' >> between two sparse matrices A=(A11 0 , A21 0) and B=(B11 0 , B21 0) where >> C will be dense in the end but I just want to calculate some selected >> entries C_ij of C. At the moment I extract submatricies for the >> corresponding rows and columns, >> > > I think that is the right way, but you should only need MatGetSubmatrix > for that. > > Thanks, > > Matt > > >> so I was wondering if there is a simpler or performancer-wise faster way. >> I assume there is not such thing as a restricted MatMatMul which just >> calculated the lets say predefined nonzero entries of C. >> >> >> These are "internal" routines that we rarely expect end users to use >> since they are specific for particular matrix implementations. As such they >> are also kind of strange to use from Fortran since none of the AIJ data >> structures can be made visible to Fortran. >> >> Could you explain why you want them from Fortran and maybe we'll have >> alternative suggestions on how you can achieve the same effect. >> >> Barry >> >> >> > On Jul 5, 2018, at 3:05 AM, Marius Buerkle <mbuer...@web.de> wrote: >> > >> > or MatMPIAIJGetLocalMatCondensed for that matter. >> > >> > >> > >> > Hi ! >> > >> > Is MatMPIAIJGetSeqAIJ implemented for fortran? >> > >> > best, >> > Marius >> >> > > > -- > 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 > > https://www.cse.buffalo.edu/~knepley/ > <http://www.caam.rice.edu/~mk51/> > -- 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 https://www.cse.buffalo.edu/~knepley/ <http://www.caam.rice.edu/~mk51/>