>> Running with the options: >> >> -ksp_type bcgs -pc_type jacobi -ksp_rtol 1e-4 -ksp_max_it 1000 >> -ksp_converged_use_initial_residual_norm -ksp_norm_type >> unpreconditioned -ksp_monitor_true_residual -ksp_converged_reason >> -ksp_view -snes_monitor -snes_converged_reason -snes_ls_monitor >> -snes_view -snes_type test -snes_test_display >> >> I get the output: >> >> Testing hand-coded Jacobian, if the ratio is >> O(1.e-8), the hand-coded Jacobian is probably correct. >> >> and the procedure stagnates, calling FormJacobian only once, and then >> FormFunction infinitely, with my own computation of ||F|| indicating >> stagnation. > > ? It is not calling it infinitely. Run with the -snes_type test option for a > small problem, with say 10 unknowns to start. > > ? Barry
Thanks for a useful hint. The smallest problem I was able to generate has around 1000 unknowns but it finally outputs something. I got some matrix, with the biggest absolute entry order 0.1 the smallest absolute entry order 1e-14, average values seem to be order 1e-8 or so. End line of the output says: Norm of matrix ratio 0.579314 difference 10.9951 (constant state 1.0) Dominik
