[petsc-users] reuse Mumps factorization for multiple RHS

[Zhang, Hong]

See case '"-num_rhs" in petsc/src/ksp/ksp/tests/ex30.c

Hong



________________________________
From: petsc-users <petsc-users-bounces at mcs.anl.gov> on behalf of Matthew Knepley <knepley at gmail.com>
Sent: Tuesday, August 4, 2020 7:29 PM
To: Anthony Paul Haas <aph at email.arizona.edu>
Cc: petsc-users <petsc-users at mcs.anl.gov>
Subject: Re: [petsc-users] reuse Mumps factorization for multiple RHS

On Tue, Aug 4, 2020 at 7:57 PM Anthony Paul Haas <aph at email.arizona.edu<mailto: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/>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20200805/616672ac/attachment-0001.html>