jburkardt

TRIANGLE_PROPERTIES\ Properties of a Triangle {#triangle_properties-properties-of-a-triangle align=”center”} ========================

TRIANGLE_PROPERTIES is a C++ library which can compute properties of a triangle, including angles, area, centroid, circumcircle, edge lengths, incircle, orientation, orthocenter, and quality.

These properties include:

Angles;
Area;
Centroid;
Circumcircle (center and radius);
Edge lengths;
Incircle (center and radius);
Orientation;
Orthocenter;
Quality: ratio of incircle radius / circumcircle radius;

Licensing: {#licensing align=”center”}

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

Languages: {#languages align=”center”}

TRIANGLE_PROPERTIES is available in a C version and a C++ version and a FORTRAN90 version and a MATLAB version and a Python version.

GEOMETRY, a C++ library which performs geometric calculations in 2, 3 and N dimensional space.

HYPERSPHERE_PROPERTIES, a C++ library which carries out various operations for an M-dimensional hypersphere, including converting between Cartesian and spherical coordinates, stereographic projection, sampling the surface of the sphere, and computing the surface area and volume.

POLYGON_PROPERTIES, a C++ library which computes properties of an arbitrary polygon in the plane, defined by a sequence of vertices, including interior angles, area, centroid, containment of a point, convexity, diameter, distance to a point, inradius, lattice area, nearest point in set, outradius, uniform sampling.

TETRAHEDRON_PROPERTIES, a C++ program which computes properties of a given tetrahedron.

TRIANGLE_ANALYZE, a C++ program which reads a triangle from a file, and then reports various properties.

TRIANGLE_INTERPOLATE, a C++ library which shows how vertex data can be interpolated at any point in the interior of a triangle.

TRIANGLES, a dataset directory which contains examples of triangles;

Source Code: {#source-code align=”center”}

triangle_properties.cpp, the source code.
triangle_properties.hpp, the include file.

Examples and Tests: {#examples-and-tests align=”center”}

triangle_properties_prb.cpp a sample calling program.
triangle_properties_prb_output.txt, the output file.

List of Routines: {#list-of-routines align=”center”}

I4_MODP returns the nonnegative remainder of I4 division.
I4_WRAP forces an I4 to lie between given limits by wrapping.
LINE_EXP_IS_DEGENERATE_ND finds if an explicit line is degenerate in ND.
LINE_EXP_PERP computes a line perpendicular to a line and through a point.
LINE_EXP2IMP converts an explicit line to implicit form in 2D.
LINE_IMP_IS_DEGENERATE finds if an implicit point is degenerate in 2D.
LINES_EXP_INT determines where two explicit lines intersect in 2D.
LINES_IMP_INT determines where two implicit lines intersect in 2D.
R8_ACOS computes the arc cosine function, with argument truncation.
R8_HUGE returns a “huge” R8.
R8_MAX returns the maximum of two R8’s.
R8_MIN returns the minimum of two R8’s.
R8_UNIFORM_01 returns a pseudorandom R8 scaled to [0,1].
R8MAT_INVERSE_2D inverts a 2 by 2 R8MAT using Cramer’s rule.
R8MAT_SOLVE uses Gauss-Jordan elimination to solve an N by N linear system.
R8MAT_TRANSPOSE_PRINT prints an R8MAT, transposed.
R8MAT_TRANSPOSE_PRINT_SOME prints some of an R8MAT, transposed.
R8VEC_COPY copies an R8VEC.
R8VEC_EQ is true if two R8VEC’s are equal.
R8VEC_NORM returns the L2 norm of an R8VEC.
R8VEC_PRINT prints an R8VEC.
SEGMENT_POINT_DIST: distance ( line segment, point ) in 2D.
SEGMENT_POINT_NEAR finds the point on a line segment nearest a point in 2D.
TIMESTAMP prints the current YMDHMS date as a time stamp.
TRIANGLE_ANGLES computes the angles of a triangle in 2D.
TRIANGLE_AREA computes the area of a triangle in 2D.
TRIANGLE_CENTROID computes the centroid of a triangle in 2D.
TRIANGLE_CIRCUMCIRCLE computes the circumcircle of a triangle in 2D.
TRIANGLE_CONTAINS_POINT finds if a point is inside a triangle in 2D.
TRIANGLE_DIAMETER computes the diameter of a triangle in 2D.
TRIANGLE_EDGE_LENGTH returns edge lengths of a triangle in 2D.
TRIANGLE_INCIRCLE computes the inscribed circle of a triangle in 2D.
TRIANGLE_ORIENTATION determines the orientation of a triangle in 2D.
TRIANGLE_ORTHOCENTER computes the orthocenter of a triangle in 2D.
TRIANGLE_POINT_DIST: distance ( triangle, point ) in 2D.
TRIANGLE_POINT_NEAR computes the nearest triangle point to a point in 2D.
TRIANGLE_QUALITY: “quality” of a triangle in 2D.
TRIANGLE_REFERENCE_SAMPLE returns random points in the reference triangle.
TRIANGLE_SAMPLE returns random points in a triangle.
TRIANGLE_XSI_TO_XY converts from barycentric to XY coordinates in 2D.
TRIANGLE_XY_TO_XSI converts from XY to barycentric in 2D.

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

Last revised on 09 November 2015.