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? 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 > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20120707/e624c010/attachment.html>
