On Sat, Jul 7, 2012 at 11:08 AM, Xin Zhao <sean.null at gmail.com> wrote:
> So if it is written as > if PETSc.COMM_WORLD.get_Rank() == 0: > L.setPreallocationNNZ((3,2)) > > will it achieve what I intend to do? > No. No no no. You do not have to call setPreallocation(). That is why I said (twice) that the matrix is already preallocated. If something is "already preallocated", it does not have to be allocated again. Matt > > > On Sat, Jul 7, 2012 at 6:04 PM, Matthew Knepley <knepley at gmail.com> wrote: > >> On Sat, Jul 7, 2012 at 11:02 AM, Xin Zhao <sean.null at gmail.com> wrote: >> >>> yeap...sorry... >>> L=DA.createMat() >>> >>> then >>> L.setPreallocationNNZ((3,2)) >>> >> >> As I said, its already preallocated. >> >> Matt >> >> >>> On Sat, Jul 7, 2012 at 6:01 PM, Matthew Knepley <knepley at gmail.com>wrote: >>> >>>> On Sat, Jul 7, 2012 at 10:58 AM, Xin Zhao <sean.null at gmail.com> wrote: >>>> >>>>> Dear all, >>>>> >>>>> I generate a matrix L by >>>>> DA =PETSc.DA().create(...some...) >>>>> L = DA.create() >>>>> >>>> >>>> Is this createMatrix()? The matrix returned from a DA is already >>>> preallocated. >>>> >>>> Matt >>>> >>>> >>>>> Then I want to preallocate memory for L >>>>> L.setPreallocationNNZ((3,2)) >>>>> This works when for mpiexec -np 1 >>>>> but it gives the error message below when mpiexec -np 4 >>>>> >>>>> [3] MatAnyAIJSetPreallocation() line 311 in >>>>> petsc4py-1.2/src/include/custom.h >>>>> [3] Operation done in wrong order >>>>> [3] matrix is already preallocated >>>>> >>>>> How to solve this? >>>>> >>>>> Thanks in advance. >>>>> >>>>> Cheers, >>>>> Xin >>>>> >>>> >>>> >>>> >>>> -- >>>> 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/20120707/3097e4b6/attachment-0001.html>
