On Fri, Mar 13, 2009 at 12:48 PM, Ravi Kannan <rxk at cfdrc.com> wrote:
> Hi, > This is Ravi Kannan from CFD Research Corporation. One basic question on > the ordering of linear solvers in PETSc: If my A matrix (in AX=B) is a > sparse matrix and the bandwidth of A (i.e. the distance between non zero > elements) is high, does PETSc reorder the matrix/matrix-equations so as to > solve more efficiently. If yes, is there any specific command to do the > above? You can reorder the matrix using the MatOrdering class. Matt > > Thanks > Ravi > > > > -----Original Message----- > From: petsc-users-bounces at mcs.anl.gov > [mailto:petsc-users-bounces at mcs.anl.gov]On Behalf Of Yixun Liu > Sent: Friday, March 06, 2009 12:50 PM > To: PETSC > Subject: matrix assembling time > > > Hi, > Using PETSc the assembling time for a mesh with 6000 vertices is about > 14 second parallelized on 4 processors, but another sequential program > based on gmm lib is about 0.6 second. PETSc's solver is much faster than > gmm, but I don't know why its assembling is so slow although I have > preallocate an enough space for the matrix. > > MatMPIAIJSetPreallocation(sparseMeshMechanicalStiffnessMatrix, 1000, > PETSC_NULL, 1000, PETSC_NULL); > > Yixun > > > -- 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/20090313/53ee7e72/attachment.htm>
