[petsc-users] Using superlu_dist in a direct solve

[Jed Brown]

You didn't say what options you were running ex6 with, but with the options
used for the tests, I see

~/petsc/src/ksp/ksp/examples/tests$ mpirun.hydra -n 2 ./ex6 -f
~/petsc/datafiles/matrices/arco1 -pc_type lu -pc_factor_mat_solver_package
superlu_dist
Number of iterations =   1
Residual norm = 2.23439e-11


You need to give precise instructions for how to reproduce the behavior you
are seeing.

Also, for experimenting with matrices read from files, we prefer
src/ksp/ksp/examples/tutorials/ex10.c because it is better commented and
has more features.


On Sun, Dec 23, 2012 at 7:08 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?
>
> -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
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>
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>
> -----------------------------------------------
>
>
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