On Fri, Jun 23, 2023 at 10:28 AM neil liu <liufi...@gmail.com> wrote:
> Dear Petsc developers, > > I am learning *PetscDTSimplexQuadrature *and plan to use it. > I found that, in the biunit simplex (tetra), > (-1,-1,-1),(1,-1,-1),(-1,1,-1),(-1,-1,1), > degree 1: npoints 4, the sum of weights = 4/3(the volume of this simplex) > degree 2 : npoints 8; > For my previous experience, I used Gauss quadrature rules, (npoints =4 , > 5, 11, 15). > Then I am curious what rule is Petsc using ? > There are two supported types: - Stroud Conical Quadrature - Minimal Symmetric Quadrature I think we prefer symmetric when it is available. > And is *PetscDTSimplexQuadrature *used by PetscFE? > Yes. Thanks, Matt > > Thanks a lot, > > Xiaodong > > -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener https://www.cse.buffalo.edu/~knepley/ <http://www.cse.buffalo.edu/~knepley/>