Plot a Triangulation

TRIANGULATION_PLOT is a C++ program which plots a triangulation.

TRIANGULATION_PLOT reads one file listing the nodes, and a second file consisting of groups of 3 or 6 nodes that make up triangles, and creates an Encapsulated PostScript image of the triangulation.


triangulation_plot prefix node_vis triangle_vis
where prefix is the common prefix for the node and triangle files, and will also be used to name the output file: and node_vis is an integer defining the node visibility: and triangle_vis is an integer defining the triangle visibility:


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


TRIANGULATION_PLOT is available in a C++ version and a FORTRAN90 version and a MATLAB version.

Related Data and Programs:

TRIANGLE, a C program which computes a triangulation of a geometric region.

TRIANGULATION, a C++ library which is useful for working with triangulations.

TRIANGULATION_DISPLAY, a MATLAB program which displays the nodes and elements of a triangulation on the MATLAB graphics screen;

TRIANGULATION_DISPLAY_OPENGL, a C++ program which reads files defining a triangulation and displays an image using Open GL.

TRIANGULATION_NODE_TO_ELEMENT, a C++ program 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_SVG, a C++ program which creates an SVG image of a triangulation, which can be displayed by a web browser.


  1. Marc deBerg, Marc Krevald, Mark Overmars, Otfried Schwarzkopf,
    Computational Geometry,
    Springer, 2000,
    ISBN: 3-540-65620-0,
    LC: QA448.D38.C65.
  2. Joseph ORourke,
    Computational Geometry,
    Second Edition,
    Cambridge, 1998,
    ISBN: 0521649765,
    LC: QA448.D38.

Source Code:

Examples and Tests:

ELBOW3 is an elbow-shaped region, triangulated using order 3 triangles.

ELL3 is an order 3 triangulation of a set of nodes in an L-shaped region.

ELL6 is an order 6 triangulation of a set of nodes in an L-shaped region.

HEX_HOLES3 puts a set of nodes into the double hexagonal hole region using CVT techniques, and creates an order 3 triangulation using TABLE_DELAUNAY.

LAKE3 uses constrained CVT methods to place nodes inside and on the boundary of the problem 14 triangulation region, a lake with an island. An order 3 triangulation is used.

List of Routines:

You can go up one level to the C++ source codes.

Last revised on 22 August 2009.