I am using MUMPS as a linear solver in my custom non-linear procedure (basically a loop). I specify the following options:
-pc_type lu -pc_factor_mat_solver_package mumps -mat_mumps_icntl_4 3 -mat_mumps_icntl_28 2 -mat_mumps_icntl_29 2 -ksp_monitor_true_residual -ksp_converged_reason -ksp_view I have noticed, that this does not actually do what I expect: I just want to unconditionally solve my system of equations with MUMPS, but I see that it actually is only a preconditioner. Gmres is in charge, performing iterations. I tried -ksp_max_it 1 but then I get divergence because residue reduction is somehow very poor (?), which does not make sense, because I expect the system be solved down to the epsilon. So is it somehow possible to just solve my Ax=b with MUMPS? Regards, Dominik
