Dear Bruno, I have already checked SSOR and AMG non of them make a difference . ILU doesn't work and gives this error: "[0]PETSC ERROR: MatSolverPackage petsc does not support matrix type mpiaij"
I don't know how to increase number of iteration. Although I have used the "SolverControl solver_control (dof_handler.n_dofs(), 1e-12*system_rhs.l2_norm());" as solver control and my n_dof is much more than 10000 but it doesn't go more than 10000 itteration !!! I was wondering which other preconditioner to use and how to increase number of iterations . Thanks On Monday, October 31, 2016 at 2:14:38 PM UTC-5, Bruno Turcksin wrote: > > Hamed, > > On Monday, October 31, 2016 at 3:01:20 PM UTC-4, Hamed Babaei wrote: >> >> This error message can indicate that you have simply not allowed a >> sufficiently large number of iterations for your iterative solver to >> converge. This often happens when you increase the size of your problem. In >> such cases, the last residual will likely still be very small, and you can >> make the error go away by increasing the allowed number of iterations when >> setting up the SolverControl object that determines the maximal number of >> iterations you allow. >> > > BlockJacobi is a bad preconditioner, you will need increase the maximal > number of iterations and/or use a better preconditioner. > > Best, > > Bruno > -- 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.
