If you are going to use Cartesian meshes only, then you may want to check out
https://dealii.org/developer/doxygen/deal.II/classFE__RaviartThomasNodal.html <https://dealii.org/developer/doxygen/deal.II/classFE__RaviartThomasNodal.html> Best praveen > On 24-Sep-2019, at 10:42 AM, Phạm Ngọc Kiên <[email protected]> wrote: > > Dear Prof. Wolfgang Bangerth, > The function fe.has_support_points() returns false. This means that the > FE_Raviart_Thomas does not have support points. > I think generalized_support_points are used for this type of finite element. > > For FE_RaviartThomas > <https://www.dealii.org/current/doxygen/deal.II/classFE__RaviartThomas.html#adc8e64d0cdb38af6e29dc9ac0279f121>(0), > are the dofs defined at the centers of the faces of a cell? > Is the order of the dofs the same as that of the faces. In that case, I think > I can loop over the faces to evaluate the shape function at a point on each > surface for the purpose of finding the direction. > > Thank you very much for your guidance. > > Best regards, > Kien > > > Vào Th 3, 24 thg 9, 2019 vào lúc 12:02 Wolfgang Bangerth > <[email protected] <mailto:[email protected]>> đã viết: > > Pham, > > > With FE_Raviart_Thomas in 3D, the dofs are defined normal to the faces of > > each > > cell. > > For example, if we use FE_RaviartThomas > > <https://www.dealii.org/current/doxygen/deal.II/classFE__RaviartThomas.html#adc8e64d0cdb38af6e29dc9ac0279f121 > > > > <https://www.dealii.org/current/doxygen/deal.II/classFE__RaviartThomas.html#adc8e64d0cdb38af6e29dc9ac0279f121>>(0), > > > > then in a cell we have 6 dofs defined on the 6 faces, and there is no dofs > > on > > the lines. > > Do we have any way to get the dof coordinates and the direction of the > > shape > > function of the dof? > > You can get the coordinates using DoFTools::map_dofs_to_support_points(). As > for the direction: That's something that the RT element does internally using > a convention that takes into account the two adjacent cells. I don't think > there is a way to determine this direction outside the element short of > evaluating the shape function at a point on the face. > > Best > W. > -- 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]. To view this discussion on the web visit https://groups.google.com/d/msgid/dealii/DD266C39-2898-4511-A900-330578D15CC6%40gmail.com.
