[petsc-users] Null space correction depends on solver?

Jed Brown jedbrown at mcs.anl.gov
Tue Aug 28 15:09:07 CDT 2012


On Tue, Aug 28, 2012 at 3:06 PM, Thomas Witkowski <
thomas.witkowski at tu-dresden.de> wrote:

> Is the null space projected out at every iteration step? If so, can you
> give me a hint were I can find the corresponding line in source code?
> Thanks.


It happens immediately after PCApply(), look at the end of
petsc-private/kspimpl.h

The problem is that it's not projected out for right preconditioning. We
have to work out whether there is a way to support null space projection in
general for right preconditioning, or whether that will require special
support per-implementation.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20120828/895776d1/attachment.html>


More information about the petsc-users mailing list