Nonlinear solve did not converge due to DIVERGED_FUNCTION_COUNT
> SNES Object: 1 MPI processes > type: newtonls > maximum iterations=50, maximum function evaluations=10000 You need to set a much higher count for number of function evaluations, say -snes_max_funcs 1.e12 Barry We should probably increase the default in PETSc. > On Sep 19, 2018, at 10:26 AM, Yingjie Wu <[email protected]> wrote: > > Dear Petsc developer: > Hi, > > Thank you very much for your previous reply . > I recently wrote an example of neutron diffusion, which shows that the > nonlinear residuals are gradually decreasing, but the program terminates in > the tenth step of the nonlinear step.The program output information is as > follows. > > -snes_fd -pc_type lu -snes_view -snes_converged_reason -snes_monitor_cancel > -ksp_converged_reason -ksp_monitor_true_residual > > iter = 0, SNES Function norm 0.999045 > 0 KSP preconditioned resid norm 1.143042621777e+02 true resid norm > 9.990445435144e-01 ||r(i)||/||b|| 1.000000000000e+00 > 1 KSP preconditioned resid norm 2.250033129078e-12 true resid norm > 3.772661181818e-14 ||r(i)||/||b|| 3.776269242757e-14 > Linear solve converged due to CONVERGED_RTOL iterations 1 > iter = 1, SNES Function norm 0.863398 > 0 KSP preconditioned resid norm 3.176569252473e+00 true resid norm > 8.633978674995e-01 ||r(i)||/||b|| 1.000000000000e+00 > 1 KSP preconditioned resid norm 7.360979829512e-14 true resid norm > 1.835881897914e-14 ||r(i)||/||b|| 2.126345184557e-14 > Linear solve converged due to CONVERGED_RTOL iterations 1 > iter = 2, SNES Function norm 0.217885 > 0 KSP preconditioned resid norm 5.796196387015e+01 true resid norm > 2.178851605144e-01 ||r(i)||/||b|| 1.000000000000e+00 > 1 KSP preconditioned resid norm 9.643306967470e-13 true resid norm > 3.884638811957e-14 ||r(i)||/||b|| 1.782883608405e-13 > Linear solve converged due to CONVERGED_RTOL iterations 1 > iter = 3, SNES Function norm 0.217871 > 0 KSP preconditioned resid norm 3.792350832110e+01 true resid norm > 2.178711262680e-01 ||r(i)||/||b|| 1.000000000000e+00 > 1 KSP preconditioned resid norm 1.369102629758e-12 true resid norm > 1.632695466260e-13 ||r(i)||/||b|| 7.493858843196e-13 > Linear solve converged due to CONVERGED_RTOL iterations 1 > iter = 4, SNES Function norm 0.217839 > 0 KSP preconditioned resid norm 2.467674567895e+01 true resid norm > 2.178387732479e-01 ||r(i)||/||b|| 1.000000000000e+00 > 1 KSP preconditioned resid norm 1.336018611676e-12 true resid norm > 2.369440379931e-14 ||r(i)||/||b|| 1.087703692324e-13 > Linear solve converged due to CONVERGED_RTOL iterations 1 > iter = 5, SNES Function norm 0.217793 > 0 KSP preconditioned resid norm 1.325333377704e+01 true resid norm > 2.177933144217e-01 ||r(i)||/||b|| 1.000000000000e+00 > 1 KSP preconditioned resid norm 2.663121116220e-13 true resid norm > 6.399802508715e-15 ||r(i)||/||b|| 2.938475189519e-14 > Linear solve converged due to CONVERGED_RTOL iterations 1 > iter = 6, SNES Function norm 0.217546 > 0 KSP preconditioned resid norm 8.654271429945e+00 true resid norm > 2.175456199462e-01 ||r(i)||/||b|| 1.000000000000e+00 > 1 KSP preconditioned resid norm 2.103027422078e-12 true resid norm > 1.896269373207e-14 ||r(i)||/||b|| 8.716651586351e-14 > Linear solve converged due to CONVERGED_RTOL iterations 1 > iter = 7, SNES Function norm 0.217024 > 0 KSP preconditioned resid norm 5.238463146996e+00 true resid norm > 2.170240974179e-01 ||r(i)||/||b|| 1.000000000000e+00 > 1 KSP preconditioned resid norm 1.538914082201e-13 true resid norm > 1.398699322805e-14 ||r(i)||/||b|| 6.444903305426e-14 > Linear solve converged due to CONVERGED_RTOL iterations 1 > iter = 8, SNES Function norm 0.215661 > 0 KSP preconditioned resid norm 3.380654310210e+00 true resid norm > 2.156611254980e-01 ||r(i)||/||b|| 1.000000000000e+00 > 1 KSP preconditioned resid norm 5.676163043758e-14 true resid norm > 2.209776803347e-15 ||r(i)||/||b|| 1.024652355979e-14 > Linear solve converged due to CONVERGED_RTOL iterations 1 > iter = 9, SNES Function norm 0.213573 > 0 KSP preconditioned resid norm 1.833370627403e+00 true resid norm > 2.135728351107e-01 ||r(i)||/||b|| 1.000000000000e+00 > 1 KSP preconditioned resid norm 1.237094085371e-13 true resid norm > 3.167085089319e-15 ||r(i)||/||b|| 1.482906329205e-14 > Linear solve converged due to CONVERGED_RTOL iterations 1 > iter = 10, SNES Function norm 0.206951 > 0 KSP preconditioned resid norm 1.011617991320e+00 true resid norm > 2.069514796799e-01 ||r(i)||/||b|| 1.000000000000e+00 > 1 KSP preconditioned resid norm 3.789650938118e-13 true resid norm > 5.695302032970e-14 ||r(i)||/||b|| 2.751998701231e-13 > Linear solve converged due to CONVERGED_RTOL iterations 1 > Nonlinear solve did not converge due to DIVERGED_FUNCTION_COUNT iterations 10 > SNES Object: 1 MPI processes > type: newtonls > maximum iterations=50, maximum function evaluations=10000 > tolerances: relative=1e-08, absolute=1e-50, solution=1e-08 > total number of linear solver iterations=11 > total number of function evaluations=10623 > norm schedule ALWAYS > Jacobian is built using finite differences one column at a time > SNESLineSearch Object: 1 MPI processes > type: bt > interpolation: cubic > alpha=1.000000e-04 > maxstep=1.000000e+08, minlambda=1.000000e-12 > tolerances: relative=1.000000e-08, absolute=1.000000e-15, > lambda=1.000000e-08 > maximum iterations=40 > KSP Object: 1 MPI processes > type: gmres > restart=30, using Classical (unmodified) Gram-Schmidt Orthogonalization > with no iterative refinement > happy breakdown tolerance 1e-30 > maximum iterations=10000, initial guess is zero > tolerances: relative=1e-05, absolute=1e-50, divergence=10000. > left preconditioning > using PRECONDITIONED norm type for convergence test > PC Object: 1 MPI processes > type: lu > out-of-place factorization > tolerance for zero pivot 2.22045e-14 > matrix ordering: nd > factor fill ratio given 5., needed 5.81047 > Factored matrix follows: > Mat Object: 1 MPI processes > type: seqaij > rows=961, cols=961 > package used to perform factorization: petsc > total: nonzeros=38169, allocated nonzeros=38169 > total number of mallocs used during MatSetValues calls =0 > not using I-node routines > linear system matrix = precond matrix: > Mat Object: 1 MPI processes > type: seqaij > rows=961, cols=961 > total: nonzeros=6569, allocated nonzeros=15485 > total number of mallocs used during MatSetValues calls =712 > not using I-node routines > > > > I don't know why the program was terminated. I really need your help. > > Thanks, > Yingjie > > >
