On Fri, May 11, 2012 at 8:20 PM, Karthik Duraisamy <dkarthik at stanford.edu>wrote:
> > > -mg_levels_4_ksp_type gmres -mg_levels_4_ksp_gmres_restart 300 > -mg_levels_4_ksp_gmres_max_it 300 -mg_levels_4_ksp_compute_eigenvalues > -mg_levels_4_pc_type none > > > Quick followup question - When solving Ax = b, I have an outer loop that > keeps feeding the same A matrix to the KSP solver, but with different > initial guesses for x. When doing this, I get slightly different eigenvalue > estimates every time (minimum real part off by 10%). I just want to confirm > that this is because of the iterative process. > Yes. A different initial residual means a different Krylov space Matt > Thanks > -- 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 -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20120511/0b528e1b/attachment.htm>
