Hi Wolfgang Thank you very much for adding this documentation! I'm trying to use the same technique on my linear elasticity problem. To compute the displacement gradient, the idea is to extract ux, uy, uz from the solution and then compute their individual gradients as you suggested. However I have some troubles:
My gradient processor is exactly the same as the one your wrote in include/deal.II/numerics/data_postprocessor.h <https://github.com/dealii/dealii/pull/4991/files#diff-0e837098279c080004cb4372efaf37e6> and the way I compute the gradient of ux is like this: > > Vector<double> ux(this->solution.size()/dim); for (unsigned int i = 0; i < ux.size(); ++i) { ux[i] = this->solution[i]; } GradientPostProcessor<dim> gradientProcessor; data.add_data_vector(scalarDofHandler, ux, gradientProcessor); where I assume the sequence of the solution is ux, uy, uz.. I guess this is not the right way to do it? And the scalarDofHandler is constructed just for the purpose of outputing nodal scalars: > FE_Q<dim> scalarFe(1); DoFHandler<dim> scalarDofHandler(this->tria); scalarDofHandler.distribute_dofs(scalarFe); When I run this code, I got: > -------------------------------------------------------- An error occurred in line <104> of file > </home/jie/dealii/source/base/subscriptor.cc> in function void dealii::Subscriptor::check_no_subscribers() const The violated condition was: counter == 0 Additional information: (none) > Stacktrace: ----------- #0 /home/jie/dealii-build/lib/libdeal_II.g.so.9.0.0-pre: > dealii::Subscriptor::check_no_subscribers() const #1 /home/jie/dealii-build/lib/libdeal_II.g.so.9.0.0-pre: > dealii::Subscriptor::~Subscriptor() #2 /home/jie/dealii-build/lib/libdeal_II.g.so.9.0.0-pre: > dealii::DataPostprocessor<2>::~DataPostprocessor() #3 ./main: dealii::DataPostprocessorVector<2>::~DataPostprocessorVector() #4 ./main: IFEM::LinearElasticSolver<2>::output(unsigned int) const #5 ./main: main -------------------------------------------------------- I pulled the latest master from dealii yesterday, and pass Test #2976 data_out_postprocessor_vector_03. My code crashed at add_data_vector. Can you see why this happened? Thank you Jie -- 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. For more options, visit https://groups.google.com/d/optout.
