MG preconditioner issue
knepley at gmail.com
Tue Mar 18 17:30:37 CDT 2008
On Tue, Mar 18, 2008 at 5:00 PM, Matt Funk <mafunk at nmsu.edu> wrote:
> i am trying out the MG preconditioner in PETSc and am encountering some
> issues. In fact when i use the MG preconditioner i get a segmentation
> violation. This does not happen with other preconditioners.
If you just do something like -pc_type mg, then you will definitely
get an error.
PC_MG is just the skeleton for a multigrid preconditioner. MG relies
of both the operator and domain, which is in general not available to PETSc.
If you want something that just works, I suggest configuring with --download-ml
or --download-hypre or --download-prometheus and running with the AMG
provided in those packages.
If you are using a DA, then you can use DMMG which provides the extra
> Running Petsc in debug mode with the -info option did not seem to produce any
> useful data (at least to me)
> I thought i'd ask if someone encountered this before i use valgrind. I am
> using 2.3.3-p8. Or does anyone have a hint on where i could start looking?
> Again, what bothers me is that the other preconditioner do not throw any sort
> of error.
What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which
their experiments lead.
-- Norbert Wiener
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