On Fri, May 15, 2009 at 4:23 PM, Christian May <cmay at phys.ethz.ch> wrote:
> On Fri, 15 May 2009, Matthew Knepley wrote: > >> 3) Run with -pc_type lu -ksp_type preonly first to test. >> > > Thanks for your hints. > This works fine: Linear solve converged due to CONVERGED_ITS iterations 1 I do not think its fine. I ran with KSP ex10: knepley at khan:/PETSc3/petsc/petsc-dev/src/ksp/ksp/examples/tutorials$ ./ex10 -f0 ~/Desktop/binaryoutput -ksp_monitor -pc_type lu -ksp_type preonly Number of iterations = 1 Residual norm 1.12564e+06 The huge residual says that LU bit the dust on roundoff with this matrix, which must have an astronomical condition number. Do you have a good physics reason that it should be almost singular? If not, I would reformulate the problem. Matt > > On Fri, 15 May 2009, Barry Smith wrote: > >> Could you please save this matrix and right hand side using >> -ksp_view_binary (just run solver like you usually do but use this command >> line option also) then post the file binaryoutput that is generated. This >> way people can trivially load the matrix and right hand side with MatLoad() >> and not monkey with parsing ASCII files. >> > > Sure, I wasn't aware of this option. The file is now available at > http://www.mayarea.de/download/binaryoutput > > Thanks a lot > Christian > -- 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/20090515/6f82b28d/attachment.htm>
