I really appreciate your answer. The library is really useful and i will dig deeper into it. I am using the latest version of dealii. Thank you very much. Best regards. Pham Ngoc Kien
Vào 04:42 PM, T.6, 25 Th1, 2019 Jean-Paul Pelteret <[email protected]> đã viết: > Dear Pham, > > Welcome to deal.II! > > Your observation is related to this frequently asked question > <https://github.com/dealii/dealii/wiki/Frequently-Asked-Questions#the-graphical-output-files-dont-make-sense-to-me----they-seem-to-have-too-many-degrees-of-freedom>. > Basically, deal.II outputs the solution on each cell individually because > we cater for the situation where the solution is discontinuous between > elements. This could arise when the solution field is discretised by > discontinuous finite elements, when there are hanging nodes in the > triangulation, or when a post-processed quantity is naturally discontinuous > between elements. This patch-based output, although maybe a bit wasteful in > the case of continuous fields due to the data duplication, is the most > robust solution for all scenarios. > > For that particular file type and the default output options, the data > points are located at the vertices of the triangulation. If you are using > the developer version of deal.II it is now possible to output the solution > to "higher-order cells” (e.g. quadratic or cubic interpolatory cells). In > this case, you’d get extra data points on the edges and interior of each > cell. > > I hope that this helped! > > Best, > Jean-Paul > > On 25 Jan 2019, at 07:35, Phạm Ngọc Kiên <[email protected]> > wrote: > > Dear Prof. Wolfgang Bangerth, > I am a newbie with deal.II library, and I have a question in this topic. > Thus, I put my question here. > I can now output my vector values results using DataPostprocessor class > into vtk file. > However, when I opened the output file, I see some data points in the file > had the same positions. I had checked with the examples (step-3) and > received the same thing. > Could you please tell me why it is? > In my limited opinion, the function: attach_dof_handler(dof_handler) will > give me the data positions which are the positions of all nodes in my mesh. > I wonder if the same data points I mentioned above are the nodes on edge, > cell, face? > I would like to thank you very much in advance. > > Best regards, > Pham Ngoc Kien > > -- > 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. > > > -- > 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. > -- 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.
