[petsc-users] Richardson: damping factor=0

[Mark Adams]

Richardson damping factor does not seem to do anything.  I set it to zero
and the solve was fine.

Am I missing something?

Thanks,
Mark

  Down solver (pre-smoother) on level 3 -------------------------------
    KSP Object:    (mg_levels_3_)     1024 MPI processes
      type: richardson
        Richardson: damping factor=0
      maximum iterations=4
      tolerances:  relative=1e-05, absolute=1e-50, divergence=10000
      left preconditioning
      using nonzero initial guess
      using NONE norm type for convergence test
    PC Object:    (mg_levels_3_)     1024 MPI processes
      type: sor
        SOR: type = local_symmetric, iterations = 1, local iterations = 1,
omega = 1
      linear system matrix followed by preconditioner matrix:
      Mat Object:       1024 MPI processes
        type: shell
        rows=33427584, cols=33427584
      Mat Object:       1024 MPI processes
        type: mpiaij
        rows=33427584, cols=33427584
        total: nonzeros=1.7272e+09, allocated nonzeros=3.4544e+09
        total number of mallocs used during MatSetValues calls =0
          not using I-node (on process 0) routines