[petsc-users] is something wrong with nnz ?

[Satish Balay]

Since you get a SEGV - I would suggest running the code in the
debugger - to check where its crashing.

Also run with valgrind to see where problems start.. Mostlikely the
issues would be change in prototypes for PETSc functions - between
releases.

Satish

On Wed, 23 Nov 2011, jean-frederic thebault wrote:

> Thanks for your response.
> 
> Sorry about that, to reduce the size of the log file, unfortunetly, I did
> took out the bad lines... In the out.log I've put in this email, I've make
> sure there are...
> 
> Actually, I don't use MatSetOption, but MatSetFromOption instead. However,
> when I called MatSetFromOption, the PETSC_COMM_WORLD was missing. But now,
> it's getting worse !! (as you could see in the out.log included in this
> email).
> 
> Le 23 novembre 2011 15:55, Jed Brown <jedbrown at mcs.anl.gov> a écrit :
> 
> >  On Wed, Nov 23, 2011 at 08:24, jean-frederic thebault <
> > jean-frederic at thebault-net.com> wrote:
> >
> >> I'm wondering what's wrong in my code. I'm using PETSc to solve a linear
> >> system, and willing to use a multi-processor computer. 9 years ago, I used
> >> petsc-2.1.3 with success. Few weeks ago, I've update petsc with the 3.1-p8
> >> version and made the necessary changes to work with. No problem. And
> >> recently, I've migrate to petsc-3.2-p5. Compilation is OK. But when I do
> >> simulation, now, I have some PETSC-ERROR in the log file, even using only
> >> one processor (see the out.log file in this email).
> >>
> >
> > You are calling MatSetOption() with the wrong number of arguments. C
> > compilers tell you about this, but Fortran compilers do not.
> >
> >
> > http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/Mat/MatSetOption.html
> >
> >
> >> However, I think I defined MatMPI and VecMPI correctly, according to the
> >> doc. The log file tell that something wrong with the nnz which should not
> >> be greater than row length (??).
> >>
> >
> > The log you sent does not say anything about nnz. Fix the call to
> > MatSetOption().
> >
> >  And also, with the previous version of PETSc I've used, the were no
> >> problem using -pc_type bjacobi and -sub_pc_type sor, juste to solve linear
> >> system doing parallel computations and because SOR is not parallelized. But
> >> now, when I use -pc_type bjacobi and -sub_pc_type sor, with 3 rank, I
> >> experiment some convergence problem during my simulation.
> >>
> >
> > These options should do the same thing they used to do. Make sure you are
> > assembling correctly. If it's still confusing, run the old and new code with
> >
> > -ksp_monitor_true_residual -ksp_converged_reason -ksp_view -pc_type
> > bjacobi -sub_pc_type sor
> >
> > and send the output of both for us to look at.
> >
> > Also note that you can use -pc_type sor even in parallel. There are
> > options for local iterations and full iterations.
> >
>