[petsc-dev] Problem with GAMG

Mark Adams mfadams at lbl.gov
Fri Jun 24 04:03:41 CDT 2016


Barry,

HEM is experimental and not intended to be fully supported.  That said, I
don't mind hardening it up.  I don't know what PETSc's policy is, if any,
on this sort of thing.

Anyway, I am trying to pound on HEM, but I get this error:

[63]PETSC ERROR: matB must have compressed row usage

I have seen this before, but I forget what to do about it. That is getting
the B matrix to have compressed row storage. Do you recall?

Thanks,
Mark


On Thu, Jun 23, 2016 at 7:59 PM, Mark Adams <mfadams at lbl.gov> wrote:

>
>
> On Wed, Jun 22, 2016 at 11:27 PM, Barry Smith <bsmith at mcs.anl.gov> 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:
>>
>>
>>
>
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