See case '"-num_rhs" in petsc/src/ksp/ksp/tests/ex30.c Hong
________________________________ From: petsc-users <petsc-users-boun...@mcs.anl.gov> on behalf of Matthew Knepley <knep...@gmail.com> Sent: Tuesday, August 4, 2020 7:29 PM To: Anthony Paul Haas <a...@email.arizona.edu> Cc: petsc-users <petsc-users@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 <a...@email.arizona.edu<mailto:a...@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/>
