[petsc-users] Using superlu_dist in a direct solve

[Sanjay Govindjee]

Sorry for the confusion.  I thought I was clear.  Here is the make line 
I was running.


         -@${MPIEXEC} -n 2 ./ex6 -ksp_type preonly  -pc_type lu 
-pc_factor_mat_solver_package superlu_dist -options_left no \
            -f arco1 > ex6_1.tmp 2>&1; \
            if (${DIFF} output/ex6_1.out ex6_1.tmp) then true; \
            else echo ${PWD} ; echo "Possible problem with with ex6_1, 
diffs above \n========================================="; fi; \
            ${RM} -f ex6_1.tmp

If you change superlu_dist to spooles it works just fine as well as any 
other iterative methods you care to try.  The matrix arcos1 was 
downloaded as per the instructions in the makefile.

I will try reproducing the superlu_dist error with 
snes/examples/tutorials/ex5 now.  (fyi under snes/examples/tests/output 
the files ex5_1.out and ex5_2.out are missing one can not run the test 
out of the box).

-sanjay


On 12/23/12 6:07 PM, Jed Brown wrote:
> 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 
> <mailto: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 <mailto: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
>>
>>
>

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