On Fri, May 24, 2013 at 5:18 PM, Michele Rosso <[email protected]> wrote:
> Using > > -pc_type gamg -pc_mg_cycle_type v -pc_gamg_agg_nsmooths 1 > -mg_coarse_sub_pc_factor_shift_type NONZERO -option_left -ksp_view > This is what debugging is about. We are not running your problem. How could this be debugged? 1) Run the problem w/o a null space so that it finishes 2) Look at the output for -ksp_view 3) Does the coarse solver say that it is shifted? 4) Are there options which were unused? Matt > still produces the same error: > > [0]PCSetData_AGG bs=1 MM=131072 > [0]PETSC ERROR: --------------------- Error Message > ------------------------------------ > [0]PETSC ERROR: Detected zero pivot in LU factorization: > see http://www.mcs.anl.gov/petsc/documentation/faq.html#ZeroPivot! > [0]PETSC ERROR: Zero pivot row 280 value 6.56964e-17 tolerance 2.22045e-14! > [0]PETSC ERROR: > ------------------------------------------------------------------------ > [0]PETSC ERROR: Petsc Release Version 3.3.0, Patch 3, Wed Aug 29 11:26:24 > CDT 2012 > [0]PETSC ERROR: See docs/changes/index.html for recent updates. > [0]PETSC ERROR: See docs/faq.html for hints about trouble shooting. > [0]PETSC ERROR: See docs/index.html for manual pages. > [0]PETSC ERROR: > ------------------------------------------------------------------------ > [0]PETSC ERROR: ./hit on a named nid15363 by Unknown Fri May 24 17:06:50 > 2013 > [0]PETSC ERROR: Libraries linked from > [0]PETSC ERROR: Configure run at > [0]PETSC ERROR: Configure options > [0]PETSC ERROR: > ------------------------------------------------------------------------ > [0]PETSC ERROR: MatPivotCheck_none() line 583 in > src/mat/impls/aij/seq//ptmp/skelly/petsc/3.3.03/cray_interlagos_build/real/src/include/petsc-private/matimpl.h > [0]PETSC ERROR: MatPivotCheck() line 602 in > src/mat/impls/aij/seq//ptmp/skelly/petsc/3.3.03/cray_interlagos_build/real/src/include/petsc-private/matimpl.h > [0]PETSC ERROR: MatLUFactorNumeric_SeqAIJ() line 585 in > src/mat/impls/aij/seq/aijfact.c > [0]PETSC ERROR: MatLUFactorNumeric() line 2803 in > src/mat/interface/matrix.c > [0]PETSC ERROR: PCSetUp_LU() line 160 in src/ksp/pc/impls/factor/lu/lu.c > [0]PETSC ERROR: PCSetUp() line 832 in src/ksp/pc/interface/precon.c > [0]PETSC ERROR: KSPSetUp() line 278 in src/ksp/ksp/interface/itfunc.c > [0]PETSC ERROR: PCSetUpOnBlocks_BJacobi_Singleblock() line 715 in > src/ksp/pc/impls/bjacobi/bjacobi.c > [0]PETSC ERROR: PCSetUpOnBlocks() line 865 in src/ksp/pc/interface/precon.c > [0]PETSC ERROR: KSPSetUpOnBlocks() line 154 in > src/ksp/ksp/interface/itfunc.c > [0]PETSC ERROR: KSPSolve() line 403 in src/ksp/ksp/interface/itfunc.c > [0]PETSC ERROR: PCSetUpOnBlocks_BJacobi_Singleblock() line 715 in > src/ksp/pc/impls/bjacobi/bjacobi.c > [0]PETSC ERROR: PCSetUpOnBlocks() line 865 in src/ksp/pc/interface/precon.c > [0]PETSC ERROR: KSPSetUpOnBlocks() line 154 in > src/ksp/ksp/interface/itfunc.c > [0]PETSC ERROR: KSPSolve() line 403 in src/ksp/ksp/interface/itfunc.c > [0]PETSC ERROR: PCMGMCycle_Private() line 20 in src/ksp/pc/impls/mg/mg.c > [0]PETSC ERROR: PCMGMCycle_Private() line 49 in src/ksp/pc/impls/mg/mg.c > [0]PETSC ERROR: PCMGMCycle_Private() line 49 in src/ksp/pc/impls/mg/mg.c > [0]PETSC ERROR: PCMGMCycle_Private() line 49 in src/ksp/pc/impls/mg/mg.c > [0]PETSC ERROR: PCApply_MG() line 326 in src/ksp/pc/impls/mg/mg.c > [0]PETSC ERROR: PCApply() line 384 in src/ksp/pc/interface/precon.c > [0]PETSC ERROR: KSPSolve_CG() line 139 in src/ksp/ksp/impls/cg/cg.c > [0]PETSC ERROR: KSPSolve() line 446 in src/ksp/ksp/interface/itfunc.c > > On 05/24/2013 02:51 PM, Jed Brown wrote: > > Michele Rosso <[email protected]> <[email protected]> writes: > > > With petsc-3.4 (which you should upgrade to), use > -mg_coarse_sub_pc_factor_shift_type NONZERO > > Actually, use this with petsc-3.3 also (and please upgrade to > petsc-3.4). > > The option you were passing was not being used. > > > > -- 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
