Stopping criteria

Nguyen, Hung V ERDC-ITL-MS Hung.V.Nguyen at
Wed Jan 14 13:54:45 CST 2009

Hello All,

I tried to solve an ill-conditioned system using cg with Jacobi
preconditioned. The KSP solver was stopping due to diverged reason within a
few iterations. Is there a way to keep KSP solver running until max_it?



hvnguyen:jade23% aprun -n 16 ./test_matrix_read -ksp_type cg -pc_type jacobi
-ksp_rtol 1.0e-15 -ksp_max_it 50000 -ksp_monitor -ksp_converged_reason
  0 KSP Residual norm 1.379074550666e+04
  1 KSP Residual norm 7.252034661743e+03
  2 KSP Residual norm 7.302184771313e+03
  3 KSP Residual norm 1.162244351275e+04
  4 KSP Residual norm 7.912531765659e+03
  5 KSP Residual norm 4.094706251487e+03
  6 KSP Residual norm 5.486131070301e+03
  7 KSP Residual norm 6.367904529202e+03
  8 KSP Residual norm 6.312767173219e+03
Linear solve did not converge due to DIVERGED_INDEFINITE_MAT iterations 9
Time in PETSc solver: 0.452695 seconds
The number of iteration       = 9
The solution residual error = 6.312767e+03

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