Thank you Jean-Paul, this works now pretty well. In fact, I had some problems in installing version 8.5.0 that have been now overcame with Timo's 8.5.1 (see Getting error during cmake configuration step and later during make run. <https://groups.google.com/forum/#!searchin/dealii/cmake%7Csort:relevance/dealii/1Zrot_Ot70Q/W_bX4WS0AgAJ> ). I dare to ask another question on exporting tensors for vtk. I understand there is no data component interpretation for tensors (I mean anything like DataComponentInterpretation::component_is_part_of_tensor) and I read that in aspect 1.3 ASPECT 1.3 released. <https://groups.google.com/forum/#!searchin/dealii/output$20tensors%7Csort:relevance/dealii/qoJwnOgg_zE/bKjbgzY66dQJ> there are "New visualization postprocessors that can output the shear stress and full stress tensors". Is it a dedicated procedure for vtk?
Of course I can manage by projecting tensors on three orthogonal directions and visualize as vectors, but I find this inelegant. Thanks Alberto *Alberto Salvadori* Dipartimento di Ingegneria Civile, Architettura, Territorio, Ambiente e di Matematica (DICATAM) Universita` di Brescia, via Branze 43, 25123 Brescia Italy tel 030 3711239 fax 030 3711312 e-mail: alberto.salvad...@unibs.it web-pages: http://m4lab.unibs.it/faculty.html http://dicata.ing.unibs.it/salvadori On Fri, Aug 18, 2017 at 3:08 PM, Jean-Paul Pelteret <jppelte...@gmail.com> wrote: > Dear Alberto, > > From the link in your previous post I presume that you're working with > deal.II 8.4.1? The feature that I've referred to was introduced in version > 8.5.0. In fact, I see now that the latest version of step-33 > <https://www.dealii.org/8.5.0/doxygen/deal.II/step_33.html#EulerEquationsPostprocessor> > has been updated to demonstrate this new functionality. Does that help? > > Regards, > Jean-Paul > > On Friday, August 18, 2017 at 2:30:12 PM UTC+2, Alberto Salvadori wrote: >> >> Thank you Jean-Paul. >> >> From the CommonInputs class >> <https://www.dealii.org/8.5.0/doxygen/deal.II/structDataPostprocessorInputs_1_1CommonInputs.html>, >> I understand that I can retrieve a pointer to the current cell by using >> this instruction, provided that the right DoFHandler is passed: >> >> const typename hp::DoFHandler<dim>::cell_iterator >> <https://www.dealii.org/8.5.0/doxygen/deal.II/group__Iterators.html#ga60277a8a3957ba4b41c1e76a87decd30> >> current_cell = input_data.template get_cell<hp::DoFHandler<dim> >(); >> >> which is indeed what I am looking for. However, I have no clue about the >> input_data variable, which is passed to the evaluate_vector_field function >> in the example that computes the fluid norm of the stress, and how it >> connects to the Post-process class that is described in step-33, i.e. >> >> template <int dim> >> class BoussinesqFlowProblem<dim>::Postprocessor : public >> DataPostprocessor >> <https://www.dealii.org/8.4.1/doxygen/deal.II/classDataPostprocessor.html> >> <dim> >> { >> public: >> Postprocessor (const unsigned int partition, >> const double minimal_pressure); >> virtual >> void >> compute_derived_quantities_vector >> <https://www.dealii.org/8.4.1/doxygen/deal.II/classDataPostprocessor.html#adf1b8b97f2b2f9c65d4c7b143f61865f> >> (const std::vector<Vector<double> >> <https://www.dealii.org/8.4.1/doxygen/deal.II/classVector.html> > &uh, >> const std::vector<std::vector<Tensor<1,dim> >> <https://www.dealii.org/8.4.1/doxygen/deal.II/classTensor.html> > > &duh, >> const std::vector<std::vector<Tensor<2,dim> >> <https://www.dealii.org/8.4.1/doxygen/deal.II/classTensor.html> > > >> &dduh, >> const std::vector<Point<dim> >> <https://www.dealii.org/8.4.1/doxygen/deal.II/classPoint.html> > >> &normals, >> const std::vector<Point<dim> >> <https://www.dealii.org/8.4.1/doxygen/deal.II/classPoint.html> > >> &evaluation_points, >> std::vector<Vector<double> >> <https://www.dealii.org/8.4.1/doxygen/deal.II/classVector.html> > >> &computed_quantities) const; >> virtual std::vector<std::string> get_names >> <https://www.dealii.org/8.4.1/doxygen/deal.II/classDataPostprocessor.html#a254f38bcdf4bdb5aa94231b695da7d55> >> () const; >> virtual >> std::vector<DataComponentInterpretation::DataComponentInterpretation> >> get_data_component_interpretation >> <https://www.dealii.org/8.4.1/doxygen/deal.II/classDataPostprocessor.html#a4d808c941d39a0c41cc9ac4afa82d47e> >> () const; >> virtual UpdateFlags >> <https://www.dealii.org/8.4.1/doxygen/deal.II/group__feaccess.html#gaa94b67d2fdcc390690c523f28019e52f> >> get_needed_update_flags >> <https://www.dealii.org/8.4.1/doxygen/deal.II/classDataPostprocessor.html#aadecdd040447b395164397ea1196f721> >> () const; >> private: >> const unsigned int partition; >> const double minimal_pressure; >> }; >> >> Can you perhaps provide some further information, to fill the gap? >> Thank you, >> >> Alberto >> >> >> *Alberto Salvadori* Dipartimento di Ingegneria Civile, Architettura, >> Territorio, Ambiente e di Matematica (DICATAM) >> Universita` di Brescia, via Branze 43, 25123 Brescia >> Italy >> tel 030 3711239 >> fax 030 3711312 >> >> e-mail: >> alberto.salvad...@unibs.it >> web-pages: >> http://m4lab.unibs.it/faculty.html >> http://dicata.ing.unibs.it/salvadori >> >> On Fri, Aug 18, 2017 at 12:38 PM, Jean-Paul Pelteret <> wrote: >> >>> Dear Alberto, >>> >>> It looks like one can already do this, although its somewhat obscurely >>> documented. Here's a link to the documentation of the CommonInputs class >>> <https://www.dealii.org/8.5.0/doxygen/deal.II/structDataPostprocessorInputs_1_1CommonInputs.html>, >>> wherein you can find a documented example of computing some solution and >>> cell dependent data. It seems to be a relatively new feature (circa 2016) >>> and I didn't know about it, so I'm happy to have found out about it as well! >>> >>> Regards, >>> Jean-Paul >>> >>> On Friday, August 18, 2017 at 11:16:40 AM UTC+2, Alberto Salvadori wrote: >>>> >>>> Dear all, >>>> >>>> I have been studying step-32 and I have found the class Postprocessor nice >>>> and effective. >>>> It is my understanding that the method compute_derived_quantities_vector >>>> within the class operates at a call level, i.e. that beyond the hood >>>> the class Postprocessor >>>> implements loops over the triangulation. >>>> >>>> I wonder if there is a way to use the cell->user_pointer in the method >>>> compute_derived_quantities_vector, i.e. if there is a way to access a >>>> reference to the cell itself. >>>> >>>> This would be very useful in case of post-processing of data that >>>> depend on the history at each Gauss point, which is indeed my case of >>>> interest. >>>> >>>> Thanks! >>>> Alberto >>>> >>> -- >>> 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 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. >>> >> >> >> >> Informativa sulla Privacy: http://www.unibs.it/node/8155 >> > -- > 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. > -- Informativa sulla Privacy: http://www.unibs.it/node/8155 -- 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. 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