Stopping criteria
Jed Brown
jed at 59a2.org
Wed Jan 14 15:14:40 CST 2009
On Wed, Jan 14, 2009 at 10:54, Nguyen, Hung V ERDC-ITL-MS
<Hung.V.Nguyen at usace.army.mil> wrote:
> Linear solve did not converge due to DIVERGED_INDEFINITE_MAT iterations 9
CG does not work for indefinite matrices, the natural thing to try is
-ksp_type minres. You can also try a nonsymmetric KSP which gives you
more choices for preconditioning, although good preconditioning for an
indefinite matrix generally uses problem-specific information. Where
does this matrix come from? How scalable does the solver need to be?
Jed
More information about the petsc-users
mailing list