On Wed, Aug 31, 2011 at 2:17 AM, Likun Tan <likunt at andrew.cmu.edu> wrote:
> > Thank you very much. So i should create the transpose matrix as MPIDense > and partition it corresponding? That is, if the matrix is partitioned into > 3 parts by row, then the transpose matrix will be partitioned into 3 parts > by column? > 1 part per process. > I have two more questions: > 1. I define a DA with PETSC_COMM_SELF, where is the array stored? Could i > use this array in every process? > It does not store anything, but with PETSC_COMM_SELF, the array will not be partitioned. > 2. I vaguely remember that matrix can only be partitioned by row, is that > true? > Sparse matrices are generally partitioned by row. This is how the AIJ classes work, and also our dense classes to mirror it. Matt > best, > Likun > > > On Tue, August 30, 2011 10:07 pm, Matthew Knepley wrote: > > On Wed, Aug 31, 2011 at 12:48 AM, Likun Tan <likunt at andrew.cmu.edu> > > wrote: > > > > > >> > >> I have MPIDense matrix, if i want to get the tranpose of the matrix, > >> what should i do? Or i should use MPISparse instead? > > > > > > If it is rectangular, create the transpose matrix first, then call > > MatTranspose. > > > > > > Matt > > > > > > > >> On Tue, August 30, 2011 7:08 pm, Matthew Knepley wrote: > >> > >>> On Tue, Aug 30, 2011 at 10:59 PM, Likun Tan <likunt at andrew.cmu.edu> > >>> wrote: > >>> > >>> > >>> > >>>> > >>>> Dear all, > >>>> > >>>> > >>>> > >>>> Can MatTranspose be used on non-squra matrix? I have a matrix with > >>>> size 200*27, and i want to get the tranpose of it. > >>>> > >>>> > >>>> > >>> > >>> I assume you are talking about dense matrices. If so, yes. > >>> > >>> > >>> > >>> > >>>> Second question is, if the 200*27 is partitioned by row, how is the > >>>> tranpose stored in each processor? Is it stored by column? > >>>> > >>> > >>> For MPIDENSE, you cannot in-place transpose unless it is square. > >>> Otherwise, > >>> you provide the transpose matrix, so you determine the layout. > >>> > >>> Matt > >>> > >>> > >>> > >>> > >>>> Thanks, > >>>> Likun > >>>> > >>>> > >>>> > >>>> > >>> > >>> > >>> -- > >>> 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 > > > > > > > > > -- 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/20110831/585ae699/attachment.htm>
