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]> 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>(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. > > > -- > ------------------------------------------------------------------------ > Wolfgang Bangerth email: [email protected] > www: http://www.math.colostate.edu/~bangerth/ > > -- > 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/4457bd19-2f78-fb99-ada7-778b6e921e7e%40colostate.edu > . > -- 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/CAAo%2BSZfT98hCAOXdpUcAJ%2Bxjr1Bt17AXzY8rJiEj4cb8s7XTAQ%40mail.gmail.com.
