All, I found an earlier email thread <http://lists.mcs.anl.gov/pipermail/petsc-users/2014-July/022207.html> on this topic. So, disregard this email.
-Gautam. On Fri, Oct 31, 2014 at 9:35 AM, Gautam Bisht <[email protected]> wrote: > Hi, > > I'm trying to learn how to use Schur complement as a preconditioner. I > ran src/snes/examples/tutorials/ex70.c for the two cases: > > ./ex70 -user_pc -ksp_view > KSP Object: 1 MPI processes > type: gmres > GMRES: restart=30, using Classical (unmodified) Gram-Schmidt > Orthogonalization with no iterative refinement > GMRES: happy breakdown tolerance 1e-30 > maximum iterations=10000, initial guess is zero > tolerances: relative=1e-05, absolute=1e-50, divergence=10000 > left preconditioning > using PRECONDITIONED norm type for convergence test > PC Object: 1 MPI processes > type: none > linear system matrix = precond matrix: > Mat Object: 1 MPI processes > type: nest > rows=72, cols=72 > Matrix object: > type=nest, rows=2, cols=2 > MatNest structure: > (0,0) : prefix="a00_", type=mpiaij, rows=48, cols=48 > (0,1) : prefix="a01_", type=mpiaij, rows=48, cols=24 > (1,0) : prefix="a10_", type=mpiaij, rows=24, cols=48 > (1,1) : prefix="a11_", type=mpiaij, rows=24, cols=24 > residual u = 1.60628e-06 > residual p = 1.2094e-05 > residual [u,p] = 1.22002e-05 > discretization error u = 0.0106473 > discretization error p = 1.85787 > discretization error [u,p] = 1.8579 > > > ./ex70 -user_ksp -ksp_view > [0]PETSC ERROR: --------------------- Error Message > -------------------------------------------------------------- > [0]PETSC ERROR: No support for this operation for this object type > [0]PETSC ERROR: Cannot locate function PCFieldSplitGetSubKSP_C in object > [0]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html > for trouble shooting. > [0]PETSC ERROR: Petsc Release Version 3.5.1, unknown > [0]PETSC ERROR: ./ex70 on a darwin-gnu-fort-debug named > gmbook.dhcp.lbnl.us by gbisht Fri Oct 31 09:28:38 2014 > [0]PETSC ERROR: Configure options -with-hdf5-dir=/opt/local/ > --with-blas-lapack-lib=/System/Library/Frameworks/Accelerate.framework/Versions/Current/Accelerate > --download-parmetis=yes --download-metis=yes --download-sundials=yes > --with-mpich=/opt/local --with-cc=/opt/local/bin/mpicc-mpich-gcc48 > --with-cxx=/opt/local/bin/mpicxx-mpich-gcc48 > --with-fc=/opt/local/bin/mpifort-mpich-gcc48 > PETSC_ARCH=darwin-gnu-fort-debug --download-sowing=1 > [0]PETSC ERROR: #1 PCFieldSplitGetSubKSP() line 1637 in > /Users/gbisht/Research/Models/PETSc/petsc3.5.1/src/ksp/pc/impls/fieldsplit/fieldsplit.c > [0]PETSC ERROR: #2 StokesSetupPC() line 113 in > /Users/gbisht/Research/Models/PETSc/petsc3.5.1/src/snes/examples/tutorials/ex70.c > [0]PETSC ERROR: #3 main() line 686 in > /Users/gbisht/Research/Models/PETSc/petsc3.5.1/src/snes/examples/tutorials/ex70.c > [0]PETSC ERROR: ----------------End of Error Message -------send entire > error message to [email protected] > application called MPI_Abort(MPI_COMM_WORLD, 56) - process 0 > > > Is my installation of PETSc incorrect? Would you suggest any particular > starting examples that demonstrate how to use Schur complement as a > preconditioner? > > Thanks, > Gautam. > >
