triangulation_triangle_neighbors, a C++ code which computes the three neighboring triangles of each triangle in a triangulation.
The user supplies a node file and a triangle file, containing the coordinates of the nodes, and the indices of the nodes that make up each triangle. Either 3-node or 6-node triangles may be used.
The program reads the data, computes the triangle neighbor information, and writes out the information to a file. In cases where one side of a triangle has no triangle neighbor, a value of -1 is assigned.
The triangle neighbor array is useful if the triangulation has to be searched to find the triangle containing a given point. It is also useful when analyzing the bandwidth of the adjacency matrix, or of a finite element matrix derived from the triangulation.
triangulation_triangle_neighbors prefixwhere prefix is the common filename prefix:
The computer code and data files described and made available on this web page are distributed under the MIT license
triangulation_triangle_neighbors is available in a C version and a C++ version and a FORTRAN90 version and a MATLAB version.
MESH_BANDWIDTH, is a C++ code which returns the geometric bandwidth associated with a mesh of elements of any order and in a space of arbitrary dimension.
RCM, a C++ code which carries out reverse Cuthill-McKee computations.
TET_MESH_RCM, a FORTRAN90 library which applies the reverse Cuthill-McKee reordering to a tetrahedral mesh of nodes in 3D.
TRIANGLE, a C program which computes a triangulation of a geometric region.
TRIANGULATION, a C++ code which carries out various operations on order 3 ("linear") or order 6 ("quadratic") triangulations.
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_CORNER, a C++ code which patches triangulations so that no triangle has two sides on the boundary.
TRIANGULATION_DELAUNAY_DISCREPANCY, a C++ code which measures the amount by which a triangulation fails the local Delaunay test;
TRIANGULATION_DISPLAY_OPENGL, a C++ code which reads files defining a triangulation and displays an image using Open GL.
TRIANGULATION_HISTOGRAM, a C++ code which computes histograms of data over a triangulation.
TRIANGULATION_L2Q, a C++ code which reads data defining a 3-node triangulation and generates midside nodes and writes out the corresponding 6-node triangulation.
TRIANGULATION_MASK, a C++ code which takes an existing triangulation and deletes triangles and their corresponding nodes as requested by the user.
TRIANGULATION_NODE_TO_ELEMENT, a C++ code which reads files describing a set of nodes, their triangulation, and the value of one or more quantities at each node, and outputs a file that averages the quantities for each element. This operation in effect creates an "order1" finite element model of the data.
TRIANGULATION_ORDER3, a directory which contains a description and examples of order 3 triangulations.
TRIANGULATION_ORDER6, a directory which contains a description and examples of order 6 triangulations.
TRIANGULATION_ORIENT, a C++ code which reads data defining a triangulation, makes sure that every triangle has positive orientation, and if not, writes a corrected triangle file.
TRIANGULATION_PLOT, a C++ code which reads data defining a triangulation and creates a PostScript image of the nodes and triangles.
TRIANGULATION_Q2L, a C++ code which reads data defining a 6-node triangulation, and subdivides each triangle into 4 3-node triangles, writing the resulting triangulation to a file.
TRIANGULATION_QUAD, a C++ code which estimates the integral of a function over a triangulated region.
TRIANGULATION_QUALITY, a C++ code which reads data defining a triangulation and computes a number of quality measures.
TRIANGULATION_REFINE, a C++ code which reads data defining a triangulation, replaces each triangle by four congruent smaller ones, and writes the new triangulation information to a file.
triangulation_triangle_neighbors_test
TRIG_TO_NEIB, a C program which reads "NODE" and "ELE" files (a format prescribed by triangle) describing a triangulation, and produces a file defining the neighbor triangles of each element; the program can also produce information about the Voronoi diagram. The program is by Lili Ju.