Stopping criteria

Jed Brown jed at
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> 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?


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