Dear Nitish, I’m not familiar with this tutorial and I don’t have much to suggest, but I have one basic question: When increasing the polynomial order of the finite element, do you increase the corresponding quadrature order as well?
Regards, Jean-Paul > On 19 Sep 2017, at 14:53, Nitish Anand <nitish....@gmail.com> wrote: > > Hey, > > I wish to solve an eigenvalue problem for a rotating disk and to understand > more about the implementation I looked into the step-36 example. > > Unfortunately, when I increase the degrees of freedom in the code (changing > line 70 to fe(3) or fe(2)) I get the following error. > > Number of active cells: 1024 > Number of degrees of freedom: 9409 > Spurious eigenvalues are all in the interval [86400,170496] > [0]PETSC ERROR: --------------------- Error Message > -------------------------------------------------------------- > [0]PETSC ERROR: Zero pivot in LU factorization: > http://www.mcs.anl.gov/petsc/documentation/faq.html#ZeroPivot > [0]PETSC ERROR: Zero pivot row 15 value 6.77626e-21 tolerance 2.22045e-14 > [0]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html for > trouble shooting. > [0]PETSC ERROR: Petsc Release Version 3.5.4, May, 23, 2015 > [0]PETSC ERROR: ./step-36 on a x86_64 named tud278242 by nitish Tue Sep 19 > 14:48:09 2017 > [0]PETSC ERROR: Configure options --with-shared-libraries=1 --with-x=0 > --with-mpi=1 --download-hypre=1 > [0]PETSC ERROR: #1 MatPivotCheck_none() line 622 in > /home/nitish/Softwares/petsc-3.5.4/include/petsc-private/matimpl.h > [0]PETSC ERROR: #2 MatPivotCheck() line 641 in > /home/nitish/Softwares/petsc-3.5.4/include/petsc-private/matimpl.h > [0]PETSC ERROR: #3 MatLUFactorNumeric_SeqAIJ_Inode() line 1424 in > /home/nitish/Softwares/petsc-3.5.4/src/mat/impls/aij/seq/inode.c > [0]PETSC ERROR: #4 MatLUFactorNumeric() line 2893 in > /home/nitish/Softwares/petsc-3.5.4/src/mat/interface/matrix.c > [0]PETSC ERROR: #5 PCSetUp_LU() line 152 in > /home/nitish/Softwares/petsc-3.5.4/src/ksp/pc/impls/factor/lu/lu.c > [0]PETSC ERROR: #6 PCSetUp() line 902 in > /home/nitish/Softwares/petsc-3.5.4/src/ksp/pc/interface/precon.c > [0]PETSC ERROR: #7 KSPSetUp() line 306 in > /home/nitish/Softwares/petsc-3.5.4/src/ksp/ksp/interface/itfunc.c > [0]PETSC ERROR: #8 PCSetUp_Redundant() line 170 in > /home/nitish/Softwares/petsc-3.5.4/src/ksp/pc/impls/redundant/redundant.c > [0]PETSC ERROR: #9 PCSetUp() line 902 in > /home/nitish/Softwares/petsc-3.5.4/src/ksp/pc/interface/precon.c > [0]PETSC ERROR: #10 KSPSetUp() line 306 in > /home/nitish/Softwares/petsc-3.5.4/src/ksp/ksp/interface/itfunc.c > [0]PETSC ERROR: #11 STSetUp_Shift() line 132 in > /home/nitish/Softwares/slepc-3.5.4/src/sys/classes/st/impls/shift/shift.c > [0]PETSC ERROR: #12 STSetUp() line 301 in > /home/nitish/Softwares/slepc-3.5.4/src/sys/classes/st/interface/stsolve.c > [0]PETSC ERROR: #13 EPSSetUp() line 207 in > /home/nitish/Softwares/slepc-3.5.4/src/eps/interface/epssetup.c > [0]PETSC ERROR: #14 EPSSolve() line 88 in > /home/nitish/Softwares/slepc-3.5.4/src/eps/interface/epssolve.c > ERROR: Uncaught exception in MPI_InitFinalize on proc 0. Skipping > MPI_Finalize() to avoid a deadlock. > > > ---------------------------------------------------- > Exception on processing: > > -------------------------------------------------------- > An error occurred in line <164> of file > </home/nitish/Softwares/dealii/source/lac/slepc_solver.cc> in function > void dealii::SLEPcWrappers::SolverBase::solve(unsigned int, unsigned int*) > The violated condition was: > ierr == 0 > Additional information: > An error with error number 71 occurred while calling a SLEPc function > -------------------------------------------------------- > > Aborting! > ---------------------------------------------------- > CMakeFiles/run.dir/build.make:57: recipe for target 'CMakeFiles/run' failed > make[3]: *** [CMakeFiles/run] Error 1 > CMakeFiles/Makefile2:264: recipe for target 'CMakeFiles/run.dir/all' failed > make[2]: *** [CMakeFiles/run.dir/all] Error 2 > CMakeFiles/Makefile2:271: recipe for target 'CMakeFiles/run.dir/rule' failed > make[1]: *** [CMakeFiles/run.dir/rule] Error 2 > Makefile:196: recipe for target 'run' failed > make: *** [run] Error 2 > > What am I missing here? Thanks for your suggestion. > > -- > The deal.II project is located at http://www.dealii.org/ > <http://www.dealii.org/> > For mailing list/forum options, see > https://groups.google.com/d/forum/dealii?hl=en > <https://groups.google.com/d/forum/dealii?hl=en> > --- > You received this message because you are subscribed to the Google Groups > "deal.II User Group" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to dealii+unsubscr...@googlegroups.com > <mailto:dealii+unsubscr...@googlegroups.com>. > For more options, visit https://groups.google.com/d/optout > <https://groups.google.com/d/optout>. -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. 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