TABLE_DELAUNAY
Triangulate Points in 2D
TABLE_DELAUNAY
is a FORTRAN90 program which
computes the Delaunay triangulation of a set of points in the plane.
Specifically, TABLE_DELAUNAY reads a data file of node coordinates,
computes the Delaunay triangulation of those points, and writes a
triangle file listing the indices of nodes that form each triangle.
Usage:
table_delaunay prefix
where prefix is the common prefix for the node and triangle files,

prefix_nodes.txt, the node coordinate file (input).

prefix_elements.txt, the element file (output).
Licensing:
The computer code and data files described and made available on this web page
are distributed under
the GNU LGPL license.
Languages:
TABLE_DELAUNAY is available in
a C++ version and
a FORTRAN90 version and
a MATLAB version.
Related Programs:
DELAUNAY_LMAP_2D,
a FORTRAN90 program which
computes the Delaunay triangulation of points in the plane under a linear mapping.
GEOMPACK,
a FORTRAN90 library which
contains the routines used for computing the Delaunay triangulation, by Barry Joe.
STRIPACK,
a FORTRAN90 library which
can compute the Delaunay triangulation or Voronoi diagram
of points on a sphere.
TABLE_IO,
a FORTRAN90 library which
supplies the routines used to read the TABLE file.
TABLE_TET_MESH,
a FORTRAN90 program which
can read a table file of 3D data, and compute a tetrahedral mesh.
TABLE_VORONOI,
a FORTRAN90 program which
can be used to compute information about
the Voronoi diagram of the points.
TRIANGULATION_DISPLAY_OPENGL,
a C++ program which
reads files defining a triangulation and displays an image using Open GL.
TRIANGULATION_PLOT,
a FORTRAN90 program which
may be used to visualize triangulations.
TRIPACK,
a FORTRAN90 library which
can compute the Delaunay triangulation of points in the plane.
Reference:

Marc deBerg, Marc Krevald, Mark Overmars,
Otfried Schwarzkopf,
Computational Geometry,
Springer, 2000,
ISBN: 3540656200,
LC: QA448.D38.C65.

Herbert Edelsbrunner,
Geometry and Topology for Mesh Generation,
Cambridge, 2001,
ISBN: 0521793092,
LC: QA377.E36.

Barry Joe,
GEOMPACK  a software package for the generation of meshes
using geometric algorithms,
Advances in Engineering Software,
Volume 13, pages 325331, 1991.

Joseph ORourke,
Computational Geometry,
Second Edition,
Cambridge, 1998,
ISBN: 0521649765,
LC: QA448.D38.

PerOlof Persson, Gilbert Strang,
A Simple Mesh Generator in MATLAB,
SIAM Review,
Volume 46, Number 2, pages 329345, June 2004.
Source Code:
Examples and Tests:
P09 is a set of 211 nodes in a region with two hexagonal
holes. When TABLE_DELAUNAY triangulates the data, the holes get
filled in.
List of Routines:

MAIN is the main program for TABLE_DELAUNAY.

CH_CAP capitalizes a single character.

CH_EQI is a case insensitive comparison of two characters for equality.

CH_TO_DIGIT returns the integer value of a base 10 digit.

DIAEDG chooses a diagonal edge.

DTRIS2 constructs a Delaunay triangulation of 2D vertices.

FILE_COLUMN_COUNT counts the number of columns in the first line of a file.

FILE_ROW_COUNT counts the number of row records in a file.

GET_UNIT returns a free FORTRAN unit number.

I4_MODP returns the nonnegative remainder of I4 division.

I4_SIGN evaluates the sign of an I4.

I4_WRAP forces an I4 to lie between given limits by wrapping.

I4MAT_TRANSPOSE_PRINT_SOME prints some of the transpose of an I4MAT.

I4MAT_WRITE writes an I4MAT file.

I4VEC_INDICATOR sets an I4VEC to the indicator vector.

LRLINE determines if a point is left of, right or, or on a directed line.

PERM_CHECK checks that a vector represents a permutation.

PERM_INVERSE inverts a permutation "in place".

R82VEC_PERMUTE permutes an R82VEC in place.

R82VEC_SORT_HEAP_INDEX_A ascending index heaps an R82VEC.

R8MAT_DATA_READ reads data from an R8MAT file.

R8MAT_HEADER_READ reads the header from an R8MAT file.

R8MAT_TRANSPOSE_PRINT_SOME prints some of an R8MAT, transposed.

S_BLANK_DELETE removes blanks from a string, left justifying the remainder.

S_TO_R8 reads an R8 from a string.

S_TO_R8VEC reads an R8VEC from a string.

S_WORD_COUNT counts the number of "words" in a string.

SWAPEC swaps diagonal edges until all triangles are Delaunay.

TIMESTAMP prints the current YMDHMS date as a time stamp.

VBEDG determines which boundary edges are visible to a point.
You can go up one level to
the FORTRAN90 source codes.
Last revised on 01 October 2009.