[petsc-users] Question on KSPSetReusePreconditioner

[Yuyun Yang]

Hello team,

I have a question on when I should be setting KSPSetReusePreconditioner to PETSC_TRUE or PETSC_FALSE. It made a pretty big difference in the solutions I get when I ran my code testing both settings, so is recalculating the preconditioner better since it will make the convergence faster and the solution more accurate? On the other hand, if the operator is updated every time step (but same nonzero pattern), will reconstructing the pc become time-consuming?

Thank you!
Yuyun
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