On Wed, Jun 22, 2016 at 11:27 PM, Barry Smith <[email protected]> wrote:

Mark,

If I use the hem coarsen type I get this error.

Does this go away with mis? Don't bother testing, it probably does.

Note that I am setting the -pc_gamg_sym_graph true flag I the debugger I do see that PCGAMGFilterGraph() has the sym flag set so it seems to me either

1) the symmetrizer doesn't actually make it symmetric or

It should be symmetric, even with roundoff, I think. You have an unsymmetric matrix structurally?

2) the detector of lack of symmetry thinks it is not symmetric when it is.

The edge weights are used to drop edges and if there is an error then you can get a structurally unsymmetric graph. Then the parallel graph algorithms barf (they assume if I know you, you know me, symmetric).

Thoughts on how to debug this?

Try with a threshold of 0. I need to take a look at it. Can I run it? I have to run for the night (in Vienna)

Thanks

barry

$ petscmpiexec -n 2 ./ex19 -pc_type gamg -da_refine 3 -mat_coarsen_type hem -pc_gamg_sym_graph true lid velocity = 0.0016, prandtl # = 1., grashof # = 1. [1]PETSC ERROR: --------------------- Error Message -------------------------------------------------------------- [1]PETSC ERROR: Petsc has generated inconsistent data [1]PETSC ERROR: Have un-symmetric graph (apparently). Use '-pc_gamg_sym_graph true' to symetrize the graph or '-pc_gamg_threshold -1.0' if the matrix is structurally symmetric. [0]PETSC ERROR: --------------------- Error Message -------------------------------------------------------------- [0]PETSC ERROR: Petsc has generated inconsistent data [0]PETSC ERROR: Have un-symmetric graph (apparently). Use '-pc_gamg_sym_graph true' to symetrize the graph or '-pc_gamg_threshold -1.0' if the matrix is structurally symmetric. [0]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html for trouble shooting. [0]PETSC ERROR: Petsc Development GIT revision: v3.7.2-596-g05491f7 GIT Date: 2016-06-22 13:31:47 -0500 [0]PETSC ERROR: ./ex19 on a arch-single named Barrys-MacBook-Pro.local by barrysmith Wed Jun 22 16:24:13 2016 [0]PETSC ERROR: [1]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html for trouble shooting. [1]PETSC ERROR: Petsc Development GIT revision: v3.7.2-596-g05491f7 GIT Date: 2016-06-22 13:31:47 -0500 [1]PETSC ERROR: ./ex19 on a arch-single named Barrys-MacBook-Pro.local by barrysmith Wed Jun 22 16:24:13 2016 [1]PETSC ERROR: Configure options --with-mpi-dir=/Users/barrysmith/libraries --with-precision=single [1]PETSC ERROR: #1 smoothAggs() line 463 in /Users/barrysmith/Src/petsc/src/ksp/pc/impls/gamg/agg.c Configure options --with-mpi-dir=/Users/barrysmith/libraries --with-precision=single [0]PETSC ERROR: #1 smoothAggs() line 463 in /Users/barrysmith/Src/petsc/src/ksp/pc/impls/gamg/agg.c [1]PETSC ERROR: #2 PCGAMGCoarsen_AGG() line 1021 in /Users/barrysmith/Src/petsc/src/ksp/pc/impls/gamg/agg.c [1]PETSC ERROR: [0]PETSC ERROR: #2 PCGAMGCoarsen_AGG() line 1021 in /Users/barrysmith/Src/petsc/src/ksp/pc/impls/gamg/agg.c [0]PETSC ERROR: #3 PCSetUp_GAMG() line 524 in /Users/barrysmith/Src/petsc/src/ksp/pc/impls/gamg/gamg.c #3 PCSetUp_GAMG() line 524 in /Users/barrysmith/Src/petsc/src/ksp/pc/impls/gamg/gamg.c [1]PETSC ERROR: #4 PCSetUp() line 968 in /Users/barrysmith/Src/petsc/src/ksp/pc/interface/precon.c [0]PETSC ERROR: #4 PCSetUp() line 968 in /Users/barrysmith/Src/petsc/src/ksp/pc/interface/precon.c [0]PETSC ERROR: #5 KSPSetUp() line 390 in /Users/barrysmith/Src/petsc/src/ksp/ksp/interface/itfunc.c [0]PETSC ERROR: #6 KSPSolve() line 599 in /Users/barrysmith/Src/petsc/src/ksp/ksp/interface/itfunc.c [1]PETSC ERROR: #5 KSPSetUp() line 390 in /Users/barrysmith/Src/petsc/src/ksp/ksp/interface/itfunc.c [1]PETSC ERROR: [0]PETSC ERROR: #7 SNESSolve_NEWTONLS() line 230 in /Users/barrysmith/Src/petsc/src/snes/impls/ls/ls.c [0]PETSC ERROR: #8 SNESSolve() line 4008 in /Users/barrysmith/Src/petsc/src/snes/interface/snes.c #6 KSPSolve() line 599 in /Users/barrysmith/Src/petsc/src/ksp/ksp/interface/itfunc.c [1]PETSC ERROR: #7 SNESSolve_NEWTONLS() line 230 in /Users/barrysmith/Src/petsc/src/snes/impls/ls/ls.c [0]PETSC ERROR: #9 main() line 159 in /Users/barrysmith/Src/petsc/src/snes/examples/tutorials/ex19.c [0]PETSC ERROR: [1]PETSC ERROR: #8 SNESSolve() line 4008 in /Users/barrysmith/Src/petsc/src/snes/interface/snes.c [1]PETSC ERROR: PETSc Option Table entries: