NAME¶

triangle - Triangle reference element

DESCRIPTION¶

The triangle reference element is

        K = { 0 < x < 1 and 0 < y < 1-x }

NUMBERING¶

      y

      2


      | +


      |   +


      |     +


      |       +


      0---------1   x

Curved high order Pk triangles (k >= 1), in 2d or 3d geometries, are supported. These triangles have additional edge-nodes and face-nodes.

THESE NODES ARE NUMBERED AS¶

first vertex, then edge-node, following the edge numbering order and orientation, and finally the face internal nodes, following the triangle lattice. See below for edge numbering and orientation.

      2               2               2


      | +             | +             | +


      |   +           7   6           9   8


      5     4         |     +        10 14  7


      |       +       8   9   5      11 12 13 6


      |         +     |         +     |         +


      0-----3-----1   0---3---4---1   0--3--4--5--1


            P2              P3              P4

IMPLEMENTATION¶

const size_t dimension = 2;
const Float  measure = 0.5;
const size_t n_vertex = 3;
const point vertex [n_vertex] = {


        point(0, 0),


        point(1, 0),


        point(0, 1) };
const size_t  n_edge = 3;
const size_t edge [n_edge][2] = {


        { 0, 1 },


        { 1, 2 },


        { 2, 0 } };

COPYRIGHT¶

Copyright (C) 2000-2018 Pierre Saramito <Pierre.Saramito@imag.fr> GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.