[petsc-users] Return value of PCFactorGetMatrix

[Matthew Knepley]

On Tue, Dec 13, 2011 at 12:51 PM, Uwe Schlifkowitz <
uwe.schlifkowitz at uibk.ac.at> wrote:

> On 13.12.2011, at 19:03, Hong Zhang wrote:
> >> I found MatGetInertia in petsc's documentation and i am not sure how to
> use it. I found an old example from petsc-2.3.1 (
> http://www.mcs.anl.gov/petsc/petsc-2.3.1/src/ksp/ksp/examples/tutorials/ex10.c.html), but things seem to have changed since that version. Can you give an
> example?
> >
> > petsc-3.2/src/ksp/ksp/examples/tests/ex33.c and ex36.c
> >
> > Hong
>
> Thank you. I already looked into ex33. My input matrix however is not in
> sbaij format:
>
> [0]PETSC ERROR: --------------------- Error Message
> ------------------------------------
> [0]PETSC ERROR: No support for this operation for this object type!
> [0]PETSC ERROR: Mat type seqaij!
>
> How do i convert the matrix to sbaij? I tried MatConvert as in ex36.c, but
> after that the matrix is not symmetric anymore.


It is time to read the manual. If you convert to SBAIJ, your matrix is
symmetric by definition.

   Matt


>
> Uwe




-- 
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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20111213/258af27f/attachment.htm>