Hi Alexander, I switch to : dealii 8.4.1 petsc 3.6.4 mumps 5.0.1
The result is still not correct. The modification I did for the code is replacing the following code in step-17.cc: * SolverControl solver_control (solution.size(),* * 1e-8*system_rhs.l2_norm());* * PETScWrappers::SolverCG cg (solver_control,* * mpi_communicator);* * PETScWrappers::PreconditionBlockJacobi preconditioner(system_matrix);* * cg.solve (system_matrix, solution, system_rhs,* * preconditioner);* with * SolverControl solver_control (**solution.size()**, 1e-12);* * PETScWrappers::SparseDirectMUMPS solver(solver_control, mpi_communicator);* * solver.set_symmetric_mode(true);* * solver.solve(system_matrix, solution, system_rhs);* Thank you very much. Regards, Shanglong 在 2016年7月26日星期二 UTC-4上午3:40:09，Alexander写道： > > > deal.II 8.4.0 >> petsc 3.3.0.3 >> MUMPS 4.10.0-p3 >> > > This PETSc and MUMPS > 4 years old. Update to the latest versions and try > again. If problem persists, provide the relevant snippet of the code. > > >> Sorry, I am not familiar with the petsc library. You meant if I call >> *solver.solve(system_matrix,solution,system_rhs)* twice, internally, it >> would use the factorization from the first time for the second solving >> process? (of course the system matrix is the same.) Do i understand this >> correctly? Thanks. >> > > Yes, correct. > > @Denis: I agree, the logic is somewhat deficient. I also think > documentation and interface itself (e.g. I have no idea why does method > set_solver_type > <https://www.dealii.org/developer/doxygen/deal.II/classPETScWrappers_1_1SparseDirectMUMPS.html#a60cb4d5b7271dfed1e82993e41f10629> > > exist and exposed to the public) could be improved. > -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
