> I see that from deal, the convergence test is always performed as > norm_of_residual_calculated_by_petsc against > tolerance_of_deal_solver_control (using SolverBase::convergence_test). I > wish to use test for the relative residual (i.e. comparing > norm_of_residual_calculated_by_petsc against some_factor*initial_residual) > as a stopping criterion, but I cannot see how this can be done from source > code (as deal.ii philosophy prescribes :-) ) from my application.
I have to admit that I haven't had time to look at your patch closely, but if the above thing is the only thing that you want to do, that is easy without any changes. Just use: SolverControl solver_control (100, 1e-10*rhs.l2_norm()); Of course this assumes that you start with x=0 (because then residual=\|Ax -b\|=\|b\|). If your x!=0, you simply compute the residual \|Ax-b\| and stick it into the absolute tolerance. Does that make sense? -- Timo Heister http://www.math.tamu.edu/~heister/ _______________________________________________ dealii mailing list http://poisson.dealii.org/mailman/listinfo/dealii
