[petsc-users] SuperLU MPI-problem

Mark Adams mfadams at lbl.gov
Sun Jul 26 08:41:24 CDT 2015

Coming in late to this thread but you are doing frequency domain NV.

Start by getting your time domain (definite, no omega shift) solves
working.  This can be a challenge for NV.  There are techiques for this but
we do not have them.  Start with plane aggregation (-pc_gamg_nsmooths 0),
this should be able to work OK, then try smoothing, this will probably not

Now add the shift.  If you are shifting to high frequency then there is no
hope w/o very special methods so use a direct solver.


On Wed, Jul 22, 2015 at 5:29 PM, Jed Brown <jed at jedbrown.org> wrote:

> "Mahir.Ulker-Kaustell at tyrens.se" <Mahir.Ulker-Kaustell at tyrens.se> writes:
> > I am solving Ax = b with a sparse, indefinite, symmetric, complex
> > matrix, can anything be said about the chances of success in using an
> > iterative method?
> Not without more information/experimentation.  You should check the
> literature for your problem domain to see what people claim is
> successful or does not work.
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