[petsc-users] Using factored complex matrices from MUMPS as a preconditioner in PETSC

[Matthew Knepley]

On Tue, Oct 10, 2017 at 10:30 PM, Evan Um <evanum at gmail.com> wrote:

> Dear Hong,
>
> I just tried to check PETSC develeoper website but couldn't find the
> updated dev version with name of hzang/update-mumps-5.1.1-cntl.
>

Hong means a branch. You get the dev repository and checkout that branch

  git checkout  hzang/update-mumps-5.1.1-cntl

  Thanks,

   Matt


> . Could you please let me know the location of the updated dev version?
> Where do I need to visit to check out the dev version with the new control
> switches? Thank you very much for your help.
>
> Best,
> Evan
>
>
>
>
>
>
> On Tue, Oct 3, 2017 at 8:34 AM, Hong <hzhang at mcs.anl.gov> wrote:
>
>> Evan,
>> ICNTL(35) and CNTL(7) are added to petsc-mumps interface in branch
>> hzhang/update-mumps-5.1.1-cntl
>>
>> You may give it a try. Once it passes our regression tests, I'll merge it
>> to petsc master branch.
>>
>> Hong
>>
>>
>> On Sun, Sep 24, 2017 at 8:08 PM, Hong <hzhang at mcs.anl.gov> wrote:
>>
>>> I'll check it.
>>> Hong
>>>
>>> On Sun, Sep 24, 2017 at 3:42 PM, Evan Um <evanum at gmail.com> wrote:
>>>
>>>> Hi Barry,
>>>>
>>>> Thanks for your comments. To activate block low rank (BLR)
>>>> approximation in MUMPS version 5.1.1, a user needs to turn on the
>>>> functionality (i.e. ICNTL(35)=1) and specify the tolerance value (e.g.
>>>> CNTL(7)=1e-4). In PETSC, I think that we can set up ICNTL and CNTL
>>>> parameters for MUMPS. I was wondering if we can still use BLR approximation
>>>> for a preconditioner for Krylov solvers.
>>>>
>>>> Best,
>>>> Evan
>>>>
>>>>
>>>> On Sat, Sep 23, 2017 at 6:45 PM, Barry Smith <bsmith at mcs.anl.gov>
>>>> wrote:
>>>>
>>>>>
>>>>> > On Sep 23, 2017, at 8:38 PM, Evan Um <evanum at gmail.com> wrote:
>>>>> >
>>>>> > Dear PETSC Users,
>>>>> >
>>>>> > My system matrix comes from finite element modeling and is complex
>>>>> and unstructured. Its typical size is a few millions-by a few millions. I
>>>>> wondering if I can use MUMPS parallel direct solver as a preconditioner in
>>>>> PETSC. For example, I want to pass factored matrices to Krylov iterative
>>>>> solvers such as QMR. Is there any PETSC+MUMPS example code for the purpose?
>>>>>
>>>>>   You don't pass factored matrices you just pass the original matrix
>>>>> and use -pc_type lu -pc_factor_mat_solver_package mumps
>>>>>
>>>>> > Can PETSC call the latest MUMPS that supports block low rank
>>>>> approximation?
>>>>>
>>>>>   No, send us info on it and we'll see if we can add an interface
>>>>>
>>>>>
>>>>> >
>>>>> > In advance, thank you very much for your comments.
>>>>> >
>>>>> > Best,
>>>>> > Evan
>>>>> >
>>>>> >
>>>>> >
>>>>> >
>>>>> >
>>>>>
>>>>>
>>>>
>>>
>>
>


-- 
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

https://www.cse.buffalo.edu/~knepley/ <http://www.caam.rice.edu/~mk51/>
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