[petsc-users] Is PCFactorSetZeroPivot() effective?

Jed Brown jedbrown at mcs.anl.gov
Thu May 31 15:12:54 CDT 2012

On Thu, May 31, 2012 at 3:08 PM, Jozsef Bakosi <jbakosi at lanl.gov> wrote:

> Using -sub_pc_factor_zeropivot does not seem to make any difference.

Run with -ksp_view and send the output. Also send the FULL error message
when it finds a zero pivot.

> >
> > > Is there a way to query the zero pivot value?
> > >
> >
> > 3) Its printed out, 1.0e-12
> >
> Yeah. I mean something like PCFactorGetZeroPivot(), so I can check what
> PETSc think I'm trying to use. The above persistent error message seems
> to indicate that whatever I'm setting is not being used.
> BTW, this error seems to happen only at larger core counts. I wonder if
> that gives you a clue as to what might be the problem (e.g. what might
> cause a zeropivot).

What discretization are you using?
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