triangulate_rectangle

triangulate_rectangle, an Octave code which computes a simple triangulation of a rectangular region.

The triangulation will be represented by two sets of data:

• node coordinates, a set of NN pairs (X(I),Y(I)) that are the coordinates of points used to define the triangulation, stored as a 2xNN real array.
• elements, a set of NE triples (I1(J),I2(J),I3(J)) that are the indices of the nodes forming the vertex of triangle J, stored as a 3xNE integer array. For each triangle, the nodes are listed in counterclockwise order.

Usage:

triangulate_rectangle ( xl, xr, xn, yb, yt, yn, base )

• xl, xr are the left and rightmost X coordinates.
• xn is the number of elements along the X direction.
• yb, yt are the bottom and topmost Y coordinates.
• yn is the number of elements along the Y direction.
• base is an optional input that is 1 for 1-based element indexing (default), or 0 for 0-based indexing.

Licensing:

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

Languages:

triangulate_rectangle is available in a MATLAB version and an Octave version.

Related Data and Programs:

triangulate_rectangle_test

fem2d_poisson_rectangle_linear, an Octave code which solves the 2d Poisson equation on a rectangle, using the finite element method (FEM), and piecewise linear triangular elements.

triangulation, an Octave code which performs various operations on order 3 (linear) or order 6 (quadratic) triangulations, including searching a Delaunay triangulation to find which triangle contains a given point.

triangulation_display, an Octave code which displays the nodes and elements of a triangulation;

Source Code:

• i4mat_transpose_print.m, prints an I4MAT, transposed;
• i4mat_transpose_print_some.m, prints some of an I4MAT, transposed;
• i4mat_write.m, writes an I4MAT out to a file.
• r8mat_transpose_print.m, prints the transpose of an R8MAT;
• r8mat_transpose_print_some.m, prints some of the transpose of an R8MAT;
• r8mat_write.m, writes an R8MAT out to a file.
• triangulate_rectangle.m, decomposes a rectangle into a grid of triangles, creating a set of nodes, and a set of elements.