**triangulation_boundary_nodes_test**,
a C++ code which
calls triangulation_boundary_nodes(), which
analyzes the triangulation
of a region, and lists those nodes which lie on the boundary
of the triangulation.

The computer code and data files described and made available on this web page are distributed under the MIT license

triangulation_boundary_nodes, a C++ code which reads data defining a triangulation, determines which nodes lie on the boundary, and writes their coordinates to a file.

- triangulation_boundary_nodes_test.sh, runs all the tests.
- triangulation_boundary_nodes_test.txt, the output file.

**ELBOW** is a curved region, looking like an elbow, that lies inside
the unit square. It is triangulated using order 3 triangles. There are
320 nodes and 568 triangles. There are 66 nodes on the boundary.

- elbow_nodes.txt, the node file.
- elbow_nodes.png, a PNG image of the nodes.
- elbow_elements.txt, the triangles.
- elbow_boundary_nodes.txt, the boundary node file.
- elbow_boundary_nodes.png, a PNG image of the boundary nodes.

**LAKE** is an irregular lake-shaped region with an "island".
It is triangulated using order 3 triangles.

- lake_nodes.txt, the node file.
- lake_nodes.png, a PNG image of the nodes.
- lake_elements.txt, the triangles.
- lake_boundary_nodes.txt, the boundary node file.
- lake_boundary_nodes.png, a PNG image of the boundary nodes.