On Wed, Mar 14, 2012 at 02:53, Klaij, Christiaan <C.Klaij at marin.nl> wrote:
> Thanks, no more problems after PCSetUP(). I am using petsc-dev, > so are you saying that MatSetNullSpace() on the block matrix [A00 > A01, A10 A11] will be enough? Can/will the null space of the > Schur complement be deduced from this? Otherwise one would still > need to "drill down" to get Schur complement matrix, right? > Unfortunately, no, and I don't think it's possible to do this automatically. Barry/Matt, this is the recurring issue of whether MatGetSubMatrix()/MatGetSchurComplement() should have the "big" matrix retain ownership, such that the user could decompose, set null spaces and auxiliary operators, restore, and have PCFieldSplit and everyone else do the right thing. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20120314/307c93a1/attachment.htm>
