On Wed, Feb 22, 2012 at 08:52, Kuhlemann, Verena <vkuhlem at emory.edu> wrote:
> I am not sure that I understand the MatStructure flag in the call of > KSPSetOperators > correctly. > > If I use KSPSetOperators(ksp, A, P, DIFFERENT_NONZERO_PATTERN) and then > solve two linear systems with the same matrix operators but different rhs > is > the preconditioner reassembled in every solve. I.e., if I call > KSPSolve(ksp,b1,x1); > KSPSolve(ksp,b2,x2); > If you don't put anything between these calls, the preconditioner will be reused. > > And if I use KSPSetOperators(ksp, A, P, SAME_PRECONDITIONER) the > preconditioner is > only setup one time and reused later. > > Or is the flag only important if I change the matrix operators in > between. > You only need to call KSPSetOperators() when the matrix changes. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20120222/0e900680/attachment-0001.htm>
