Further question about PC with Jaocbi Row Sum

[Matthew Knepley]

On Fri, Apr 11, 2008 at 3:56 PM, Shi Jin <jinzishuai at yahoo.com> wrote:
> Thank you.
>  Suppose I have a diagonal matrix, what is the best way to invert it in PETSc?

If you have a diagonal matrix, you just use -ksp_type preonly -pc_type jacobi

   Matt

>  Do I have to install the external packages superlu_dist or mumps?
>  I realized that LU or Cholesky decomposition does not work with MPIAIJ matrices.
>  I also know the best way is probably to directly call Vector operations directly.
>  However, I want to keep the same KSPSolve structure so that the same code can be used  for non-diagonal MPIAIJ matrices without changing each call to KSPSolve.
>  Thank you very much.
>
>  Shi
>  > Then you may try direct sparse linear solver,
>  > sequential run:
>  > -ksp_type preonly -pc_type cholesky
>  > parallel run (install external packages superlu_dist or mumps):
>  > -ksp_type preonly -pc_type lu -mat_type superlu_dist
>  > or
>  > -ksp_type preonly -pc_type cholesky -mat_type sbaijmumps
>  >
>  > Hong
>  >
>
>
>
>
>
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