Hello Praveen, Thank you so much. I am wondering if you could tell me which
limiters you used, because if it is too hard for me to implement this limiter, I will have to try other ones. I am a newbie to C++, but will try to read your codes to see if I can make it. Thanks, Jiaqi 2016-09-19 23:43 GMT-04:00 Praveen C <cprav...@gmail.com>: > Hello Jiaqi > > I was interested in this some years back though I didnt pursue it after > some initial attempt. > > See this > > https://groups.google.com/forum/m/?hl=en-GB#!topic/dealii/gaongNBSXfY > > I tried writing an fespace based on FE_DGPNonparametric which does not use > a mapping and the shape functions are directly evaluated in physical space. > I attempted it here > > https://bitbucket.org/cpraveen/deal_ii/src/f1d8a33d4b5c7af02 > cca8e9e3c7f357d56c4c14d/fe_dgt/?at=master > > You need to modify fevalues so that it can use solution on one cell but > evaluate it on a different cell. See the reinit functions > > https://bitbucket.org/cpraveen/deal_ii/src/f1d8a33d4b5c7af02 > cca8e9e3c7f357d56c4c14d/fe_dgt/fe_values.cc?at=master& > fileviewer=file-view-default > > I dont remember clearly but this seemed to be working fine. Only problem > was that the shape functions were not orthogonal. > > I used this fe_dgt space here > > https://bitbucket.org/cpraveen/deal_ii/src/f1d8a33d4b5c7af02 > cca8e9e3c7f357d56c4c14d/dg/1d_scalar_taylor/?at=master > > https://bitbucket.org/cpraveen/deal_ii/src/f1d8a33d4b5c7af02 > cca8e9e3c7f357d56c4c14d/dg/2d_scalar_unsteady_taylor/?at=master > > There may be other discussion in mailing list related to this which I have > forgotten now. > > It *should be possible* to add a similar reinit function to FE_DGP with > MappingCartesian, and achieve what you want. The shape functions would be > orthogonal. So one would use it as (some syntax could be wrong here) > > fe_values.reinit(cell); > std::vector<Point<dim>>& points = fe_values.get_quadrature_points(); > fe_values_nbr.reinit(nbr_cell, points); > > The last reinit function should convert "points" to local coordinates on > nbr_cell and evaluate whatever it wants. > > Or you can modify my fe_dgt to use Legendre polynomials. > > On general grids, this is more difficult if you want to have orthogonal > shape functions. Only way would be to implement some gram-schmidt process. > If you dont care for orthogonality, then something like fe_dgt above works. > > Best > Praveen​ > > -- > 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. > -- Jiaqi Zhang Graduate student Department of Mathematics Virginia Tech -- 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.
