On Thu, 6 Apr 2017, Adriano Côrtes wrote:
It's me again. Checking the code I realised that this command line
option "--solver_system_names", also appears in the
petsc_auto_fieldsplit.C
Is there a command line option also to setup (automatically) the
PCFIELDSPLIT such that I can use physics based preconditioners, like
Least Square Commutator (LSC), that I know we can call in PETSc with
a simple combination of command line options, once the fields blocks
are well defined?
"--solver_variable_names" tells libMesh to set up field splits, which
by default splits your system into an index set for each variable.
"--solver_group_adrianossysname_adrianosvarname adrianosgroup" lets
you put more than one variable into a single group.
My big question actually is how to setup all this framework and put
them to work? Is there any worked example?
I'm afraid not. Despite lots of attempts I never got my target
application to solve faster with a fancy field split than with
hand-tweaked additive Schwarz + ILU, so I dropped the whole project.
I dropped it in working order, however, so hopefully your physics will
be more tractable with it than mine was.
In hindsight I should have added some example usage to one of the
incompressible-Navier-Stokes systems. I may come back to the whole
problem after we're done getting geometric multigrid going; IIRC
people have had very good results using GMG internal to e.g. Schur
complement solvers.
---
Roy
------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
_______________________________________________
Libmesh-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/libmesh-users
