[petsc-users] Undestanding how to increase the overlap

[Matthew Knepley]

On Thu, Jan 18, 2024 at 9:24 AM TARDIEU Nicolas via petsc-users <
petsc-users at mcs.anl.gov> wrote:

> Dear PETSc Team,
>
> I am trying to understand how to increase the overlap of a matrix.
> I wrote the attached petsc4py script where I build a simple matrix and
> play with the increaseOverlap method. Unfortunately, before and after the
> call, nothing changes in the index set. FYI, I have tried to mimic
> src/ksp/ksp/tutorials/ex82.c
> <https://petsc.org/main/src/ksp/ksp/tutorials/ex82.c.html> line 72:76.
> Here is how I run the script : "mpiexec -n 2 python test_overlap.py"
>
> Could you please indicate what I am missing ?
>

Usually matrix functions like this take input in global indices. It looks
like your isovl is in local indices. Am I reading that correctly?

  Thanks,

     Matt


> Regards,
> Nicolas
> --
> Nicolas Tardieu
> Ing PhD Computational Mechanics
> EDF - R&D Dpt ERMES
> PARIS-SACLAY, FRANCE
>
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-- 
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.cse.buffalo.edu/~knepley/>
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