quad_mesh_test, a FORTRAN90 code which calls quad_mesh(), which carries out operations involving meshes of quadrilaterals.
The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.
quad_mesh, a FORTRAN90 code which handles meshes of quadrilaterals over a 2D region;
EXAMPLE1 is a mesh made up of squares of uniform size. The squares are arranged in a grid with a few irregularities, however. In particular, there is an interior hole.
EXAMPLE2 is a mesh made up of quadrilaterals that are "trying" to tile a semicircle. The row of elements that touches the origin is degenerate, and are essentially triangles. The elements vary in area.
SAMPLE_QUAD demonstrates how a single quadrilateral can be randomly sampled.