On Tue, Mar 18, 2008 at 5:00 PM, Matt Funk <[email protected]> wrote:
Hi,
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 on knowledge 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 information. Matt
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.
thanks mat
-- 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