[petsc-users] Using superlu_dist in a direct solve

[Matthew Knepley]

On Sun, Dec 23, 2012 at 9:37 PM, Sanjay Govindjee <s_g at berkeley.edu> wrote:

>  I decided to go with ksp/ksp/exampeles/tutorials/ex2.c; I was unsure how
> to convert the run lines for snes/examples/ex5.c to work with a direct
> solver as I am not versed in SNES options.
>
> Notwithstanding something strange is happening only on select examples.
> With ksp/ksp/exampeles/tutorials/ex2.c and the run line:
>
> -@${MPIEXEC} -n 2 ./ex2 -ksp_monitor_short -m 20 -n 20 -ksp_type preonly
> -pc_type lu -pc_factor_mat_solver_package superlu_dist
>
> I get good results (of the order):
>
> Norm of error 1.85464e-14 iterations 1
>
> using both superlu_dist and spooles.
>
> My BLAS/LAPACK: -llapack -lblas (so native to my machine).
>
> If you can guide me on a run line for the snes ex5.c I can try that too.
> I'll also try to construct a GCC build later to see if that is an issue.
>

Same line on ex5, but ex2 is good enough. However, it will not tell us
anything new. Try another build.

   Matt


> -sanjay
>
>
> On 12/23/12 5:58 PM, Matthew Knepley wrote:
>
> On Sun, Dec 23, 2012 at 8:08 PM, Sanjay Govindjee <s_g at berkeley.edu>wrote:
>
>>  Not sure what you mean by where is your matrix?  I am simply running ex6
>> in the ksp/examples/tests directory.
>>
>> The reason I ran this test is because I was seeing the same behavior with
>> my finite element code (on perfectly benign problems).
>>
>> Is there a built-in test that you use to check that superlu_dist is
>> working properly with petsc?
>> i.e. something you know that works with with petsc 3.3-p5?
>>
>
>  1) Run it on a SNES ex5 (or KSP ex2), which is a nice Laplacian
>
>  2) Compare with MUMPS
>
>     Matt
>
>
>>  -sanjay
>>
>>
>>
>> On 12/23/12 4:56 PM, Jed Brown wrote:
>>
>> Where is your matrix? It might be ending up with a very bad pivot. If the
>> problem can be reproduced, it should be reported to the SuperLU_DIST
>> developers to fix. (Note that we do not see this with other matrices.) You
>> can also try MUMPS.
>>
>>
>> On Sun, Dec 23, 2012 at 6:48 PM, Sanjay Govindjee <s_g at berkeley.edu>wrote:
>>
>>>  I wanted to use SuperLU Dist to perform a direct solve but seem to be
>>> encountering
>>> a problem.  I was wonder if this is a know issue and if there is a
>>> solution for it.
>>>
>>> The problem is easily observed using ex6.c in src/ksp/ksp/examples/tests.
>>>
>>> Out of the box: make runex6 produces a residual error of O(1e-11), all
>>> is well.
>>>
>>> I then changed the run to run on two processors and add the flag
>>> -pc_factor_mat_solver_package spooles  this produces a residual error of
>>> O(1e-11), all is still well.
>>>
>>> I then switch over to -pc_factor_mat_solver_package superlu_dist and the
>>> residual error comes back as 22.6637!  Something seems very wrong.
>>>
>>> My build is perfectly vanilla:
>>>
>>> export PETSC_DIR=/Users/sg/petsc-3.3-p5/
>>> export PETSC_ARCH=intel
>>>
>>> ./configure --with-cc=icc --with-fc=ifort  \
>>> -download-{spooles,parmetis,superlu_dist,prometheus,mpich,ml,hypre,metis}
>>>
>>> make PETSC_DIR=/Users/sg/petsc-3.3-p5/ PETSC_ARCH=intel all
>>> make PETSC_DIR=/Users/sg/petsc-3.3-p5/ PETSC_ARCH=intel test
>>>
>>> -sanjay
>>>
>>
>>
>>  --
>> -----------------------------------------------
>> Sanjay Govindjee, PhD, PE
>> Professor of Civil Engineering
>> Vice Chair for Academic Affairs
>>
>> 779 Davis Hall
>> Structural Engineering, Mechanics and Materials
>> Department of Civil Engineering
>> University of California
>> Berkeley, CA 94720-1710
>>
>> Voice:  +1 510 642 6060
>> FAX:    +1 510 643 5264s_g at berkeley.eduhttp://www.ce.berkeley.edu/~sanjay
>> -----------------------------------------------
>>
>> New Books:
>>
>> Engineering Mechanics of Deformable
>> Solids: A Presentation with Exerciseshttp://www.oup.com/us/catalog/general/subject/Physics/MaterialsScience/?view=usa&ci=9780199651641http://ukcatalogue.oup.com/product/9780199651641.dohttp://amzn.com/0199651647
>>
>>
>> Engineering Mechanics 3 (Dynamics)http://www.springer.com/materials/mechanics/book/978-3-642-14018-1http://amzn.com/3642140181
>>
>> -----------------------------------------------
>>
>>
>
>
>  --
> 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
>
>
>


-- 
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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