In snes examples/tutorials ex55, there is a comment saying that one can use the following options for running this example:
./ex55 -ksp_type fgmres -pc_type fieldsplit -pc_fieldsplit_detect_saddle_point -pc_fieldsplit_type schur -pc_fieldsplit_schur_precondition self -fieldsplit_1_ksp_type fgmres -fieldsplit_1_pc_type lsc -snes_vi_monitor -ksp_monitor_true_residual -fieldsplit_ksp_monitor -fieldsplit_0_pc_type hypre -da_grid_x 65 -da_grid_y 65 -snes_atol 1.e-11 -ksp_rtol 1.e-8 However it gives me the following error message: 0 SNES VI Function norm 3.976439267245e-05 Active lower constraints 2001/2241 upper constraints 314/397 Percent of total 0.136982 Percent of bounded 0.182643 [0]PETSC ERROR: ------------------------------------------------------------------------ [0]PETSC ERROR: Caught signal number 11 SEGV: Segmentation Violation, probably memory access out of range [0]PETSC ERROR: Try option -start_in_debugger or -on_error_attach_debugger [0]PETSC ERROR: or see http://www.mcs.anl.gov/petsc/documentation/faq.html#valgrind[0]PETSC ERROR: or try http://valgrind.org on GNU/linux and Apple Mac OS X to find memory corruption errors [0]PETSC ERROR: likely location of problem given in stack below [0]PETSC ERROR: --------------------- Stack Frames ------------------------------------ [0]PETSC ERROR: Note: The EXACT line numbers in the stack are not available, [0]PETSC ERROR: INSTEAD the line number of the start of the function [0]PETSC ERROR: is given. [0]PETSC ERROR: [0] PCFieldSplitSetDefaults line 310 src/ksp/pc/impls/fieldsplit/fieldsplit.c [0]PETSC ERROR: [0] PCSetUp_FieldSplit line 457 src/ksp/pc/impls/fieldsplit/fieldsplit.c [0]PETSC ERROR: [0] PCSetUp line 868 src/ksp/pc/interface/precon.c [0]PETSC ERROR: [0] KSPSetUp line 192 src/ksp/ksp/interface/itfunc.c [0]PETSC ERROR: [0] SNESSolve_VINEWTONRSLS line 347 src/snes/impls/vi/rs/virs.c [0]PETSC ERROR: [0] SNESSolve line 3589 src/snes/interface/snes.c [0]PETSC ERROR: --------------------- Error Message ------------------------------------ [0]PETSC ERROR: Signal received! [0]PETSC ERROR: ------------------------------------------------------------------------ [0]PETSC ERROR: Petsc Release Version 3.4.4, Mar, 13, 2014 [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: ./ex55 on a linux-gnu named Huis-MacBook-Pro.local by Paul Tue Jul 15 18:42:59 2014 [0]PETSC ERROR: Libraries linked from /usr/local/petsc-3.4.4/linux-gnu/lib [0]PETSC ERROR: Configure run at Fri Jun 13 23:47:57 2014 [0]PETSC ERROR: Configure options PETSC_ARCH=linux-gnu --with-cc=gcc --with-fc=gfortran --download-mpich [0]PETSC ERROR: ------------------------------------------------------------------------ [0]PETSC ERROR: User provided function() line 0 in unknown directory unknown file application called MPI_Abort(MPI_COMM_WORLD, 59) - process 0 [unset]: aborting job: application called MPI_Abort(MPI_COMM_WORLD, 59) - process 0 Do you might know what's going on? Another strange issue is that I typed the following command: ./ex55 -help | grep -A5 fieldsplit The output is: eisenstat ilu icc cholesky asm gasm ksp composite redundant nn mat fieldsplit galerkin exotic hmpi asa cp lsc redistribute svd gamg tfs (PCSetType) -pc_use_amat: <FALSE> use Amat (instead of Pmat) to define preconditioner in nested inner solves (PCSetUseAmat) ILU Options -pc_factor_in_place: <FALSE> Form factored matrix in the same memory as the matrix (PCFactorSetUseInPlace) -pc_factor_fill <1>: Expected non-zeros in factored matrix (PCFactorSetFill) -pc_factor_shift_type <INBLOCKS> (choose one of) NONE NONZERO POSITIVE_DEFINITE INBLOCKS (PCFactorSetShiftType) While I'm actually expecting to have something such as -pc_fieldsplit_detect_saddle_point coming out. Then isn't it one of the possible options?
