[petsc-users] reuse Mumps factorization for multiple RHS

[Matthew Knepley]

On Tue, Aug 4, 2020 at 7:57 PM Anthony Paul Haas <aph at email.arizona.edu>
wrote:

> Hello,
>
> When using Mumps to solve a linear system of equations (see below), can I
> reuse the factorization to solve for multiple RHS, ie, can I use KSPSolve multiple
> times while only building a different RHS in between the calls to KSPSolve
> ?
>

Yes. It should detect that you have not changed the operator for the KSP
and thus not refactor the matrix.

  Thanks,

     Matt


> Thanks,
>
> Anthony
>
> call KSPSetType(self%ksp,KSPPREONLY,self%ierr_ps)
>
> call KSPGetPC(self%ksp,pc,self%ierr_ps)
>
>
>
>
>
> call PCSetType(pc,PCLU,self%ierr_ps)
>
>
>
>
>
> call PCFactorSetMatSolverPackage(pc,MATSOLVERMUMPS,self%ierr_ps)
>
> call PCFactorSetUpMatSolverPackage(pc,self%ierr_ps)
>


-- 
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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