Hi there, so far I had a great learning curve, but now i seem to be stuck. I try to solve my own little PDE, which is a system of multiple nonlinear time dependent equations and read through plenty of the Tutorials. Using Dirichlet-Boundary conditions everything worked out finally, now I wanted to switch to Neuman boundary conditions and I get some issue I do not understand.
I followed mostly step-72 to understand how to use automatic differentiation. For Neumann boundary conditions I have now to integrate over the boundary of my domain, therefore I jumped right into the cell_worker lambda function (step-72) right after the for-loop over all quadrature points. There I tried to stick to the example given in here: https://dealii.org/developer/doxygen/deal.II/classMeshWorker_1_1ScratchData.html and created a for loop: for (unsigned int f = 0; f < GeometryInfo<dim>::faces_per_cell; ++f) { if (cell->face(f)->at_boundary())//(face->at_boundary()) { std::cout << "reached line 1032" << std::endl; const auto &fe_face_values = scratch_data.reinit(cell, f); std::cout << "reached line 1034" << std::endl; /* here integration using fe_face_value should happen*/ but the last cout never gets executed, but the code crashes. I get a long but cryptic (to me?) stacktrace but also the following error message: An error occurred in line <3044> of file <./source/fe/fe_values.cc> in function dealii::FEValuesBase<dim, spacedim>::FEValuesBase(unsigned int, unsigned int, dealii::UpdateFlags, const dealii::Mapping<dim, spacedim>&, const dealii::FiniteElement<dim, spacedim>&) [with int dim = 2; int spacedim = 2] The violated condition was: n_q_points > 0 Additional information: There is nothing useful you can do with an FEValues object when using a quadrature formula with zero quadrature points! >From here I am quite unsure what I did wrong or how else to create the FEFaceValues Object? I would be really thankful about any hint! -- 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 dealii+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/dealii/03776b07-f004-4099-9428-36feb17d706fn%40googlegroups.com.
