[petsc-users] PCMG questions

[Mark Adams]

I have a MG hierarchy that I construct manually with DMRefine and
DMPlexExtrude.

* The solver works great with chevy/sor but with chevy/sor it converges
slowly or I get indefinite PC errors from CG. And the eigen estimates in
cheby are really high, like 10-15.

* I tried turning galerkin=none and I got this error.

Any thoughts on either of these issues?

Thanks,
Mark

[0]PETSC ERROR: --------------------- Error Message
--------------------------------------------------------------
[0]PETSC ERROR: Must call DMShellSetGlobalVector() or
DMShellSetCreateGlobalVector()
[0]PETSC ERROR: WARNING! There are option(s) set that were not used! Could
be the program crashed before they were used or a spelling mistake, etc!
[0]PETSC ERROR:   Option left: name:-ksp_converged_reason (no value)
source: command line
[0]PETSC ERROR:   Option left: name:-mg_levels_esteig_ksp_type value: cg
source: command line
[0]PETSC ERROR:   Option left: name:-mg_levels_pc_type value: sor source:
command line
[0]PETSC ERROR:   Option left: name:-options_left (no value) source:
command line
[0]PETSC ERROR: See https://petsc.org/release/faq/ for trouble shooting.
[0]PETSC ERROR: Petsc Development GIT revision: v3.19.1-224-g9ed82936d20
 GIT Date: 2023-05-07 12:33:48 -0400
[0]PETSC ERROR: ./ex96 on a arch-macosx-gnu-O named MarksMac-302.local by
markadams Tue May  9 12:26:52 2023
[0]PETSC ERROR: Configure options CFLAGS="-g  -Wall" CXXFLAGS="-g  -Wall"
COPTFLAGS=-O CXXOPTFLAGS=-O --with-cc=/usr/local/opt/llvm/bin/clang
--with-cxx=/usr/local/opt/llvm/bin/clang++ --download-mpich
--with-strict-petscerrorcode --download-triangle=1 --with-x=0
--with-debugging=0 --download-hdf5=1 PETSC_ARCH=arch-macosx-gnu-O
[0]PETSC ERROR: #1 DMCreateGlobalVector_Shell() at
/Users/markadams/Codes/petsc/src/dm/impls/shell/dmshell.c:210
[0]PETSC ERROR: #2 DMCreateGlobalVector() at
/Users/markadams/Codes/petsc/src/dm/interface/dm.c:1022
[0]PETSC ERROR: #3 DMGetNamedGlobalVector() at
/Users/markadams/Codes/petsc/src/dm/interface/dmget.c:377
[0]PETSC ERROR: #4 DMRestrictHook_SNESVecSol() at
/Users/markadams/Codes/petsc/src/snes/interface/snes.c:649
[0]PETSC ERROR: #5 DMRestrict() at
/Users/markadams/Codes/petsc/src/dm/interface/dm.c:3407
[0]PETSC ERROR: #6 PCSetUp_MG() at
/Users/markadams/Codes/petsc/src/ksp/pc/impls/mg/mg.c:1074
[0]PETSC ERROR: #7 PCSetUp() at
/Users/markadams/Codes/petsc/src/ksp/pc/interface/precon.c:994
[0]PETSC ERROR: #8 KSPSetUp() at
/Users/markadams/Codes/petsc/src/ksp/ksp/interface/itfunc.c:406
[0]PETSC ERROR: #9 KSPSolve_Private() at
/Users/markadams/Codes/petsc/src/ksp/ksp/interface/itfunc.c:824
[0]PETSC ERROR: #10 KSPSolve() at
/Users/markadams/Codes/petsc/src/ksp/ksp/interface/itfunc.c:1070
[0]PETSC ERROR: #11 SNESSolve_KSPONLY() at
/Users/markadams/Codes/petsc/src/snes/impls/ksponly/ksponly.c:48
[0]PETSC ERROR: #12 SNESSolve() at
/Users/markadams/Codes/petsc/src/snes/interface/snes.c:4663
[0]PETSC ERROR: #13 main() at ex96.c:433
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20230509/390bb112/attachment.html>