[petsc-users] ML and -pc_factor_shift_nonzero

[Matthew Knepley]

On Tue, Apr 13, 2010 at 2:49 PM, <tribur at vision.ee.ethz.ch> wrote:

> Hi,
>
> using ML I got the error
>
> "[0]PETSC ERROR: Detected zero pivot in LU factorization"
>
> As recommended at
> http://www.mcs.anl.gov/petsc/petsc-as/documentation/troubleshooting.html,
> I tried -pc_factor_shift_nonzero but it doesn't have the desired effect
> using ML.
>
> How do I have to formulate the command line option? What does
> -[level]_pc_factor_shift_nonzero mean? What other parallel preconditioner
> could I try besides Hypre/Boomeramg or ML?
>

This means the MG level, like 2. You can see all available options using
-help.

  Matt


> Thanks in advance for your precious help,
>
> Kathrin
>
>
>


-- 
What most experimenters take for granted before they begin their experiments
is infinitely more interesting than any results to which their experiments
lead.
-- Norbert Wiener
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