It is actually my stupid mistake in solvercontrol, I used SolverControl solver_control (dof_handler.n_dofs(),1e-12) This works when the geometry size in the order of 1, but fails at 1e-6, or even 1e-9. Here I actually want to make a micrometer or nanometer size structure.
later, I changed the control into SolverControl solver_control (5*system_rhs.size(),1e-12*system_rhs.l2_norm() ) this works well for structure size of um or nm. I think previous setting may lead to a loss of precision so that the results are always incorrect. Thanks for your ideas and have a nice day, Mark 2017-10-12 14:29 GMT+02:00 Wolfgang Bangerth <[email protected]>: > On 10/12/2017 03:02 AM, Mark Ma wrote: > >> >> Thanks for your useful advice. Finally I solved this problem. >> > > So what was the problem? Maybe we can learn from your example? > > > Best > W. > > -- > ------------------------------------------------------------------------ > Wolfgang Bangerth email: [email protected] > www: http://www.math.colostate.edu/~bangerth/ > > -- > The deal.II project is located at http://www.dealii.org/ > For mailing list/forum options, see https://groups.google.com/d/fo > rum/dealii?hl=en > --- You received this message because you are subscribed to a topic in the > Google Groups "deal.II User Group" group. > To unsubscribe from this topic, visit https://groups.google.com/d/to > pic/dealii/5hC7jODg-7k/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- 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.
