[petsc-users] Failure of MUMPS

[David Knezevic]

On Fri, Oct 5, 2018 at 9:16 PM Mike Wick <michael.wick.1980 at gmail.com>
wrote:

> Hi Hong:
>
> There is no explicit error message actually. The solver converge in 0
> iteration and returns an nan number. Looks like a zero pivoting problem.
>
> Mike
>

I use MatMumpsGetInfo
<https://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/Mat/MatMumpsGetInfo.html>
to
get error info returned by MUMPS, e.g.

PetscInt info_1;
MatMumpsGetInfo(pc_mat, 1, &info_1);

Then you can check the value of info_1 to get error diagnostics. One error
that I run into sometimes is when info_1 is -9, in which case I increase
icntl_14 and try again.

Best,
David



>
> On Fri, Oct 5, 2018 at 6:12 PM Zhang, Hong <hzhang at mcs.anl.gov> wrote:
>
>> Mike:
>>
>>> Hello PETSc team:
>>>
>>> I am trying to solve a PDE problem with high-order finite elements. The
>>> matrix is getting denser and my experience is that MUMPS just outperforms
>>> iterative solvers.
>>>
>>> For certain problems, MUMPS just fail in the middle for no clear reason.
>>> I just wander if there is any suggestion to improve the robustness of
>>> MUMPS? Or in general, any suggestion for interative solver with very
>>> high-order finite elements?
>>>
>>
>> What error message do you get when MUMPS fails? Out of memory, zero
>> pivoting, or something?
>>  Hong
>>
>
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