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geometry.html
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<html>
<head>
<title>
GEOMETRY - Geometric Calculations
</title>
</head>
<body bgcolor="#EEEEEE" link="#CC0000" alink="#FF3300" vlink="#000055">
<h1 align = "center">
GEOMETRY <br> Geometric Calculations
</h1>
<hr>
<p>
<b>GEOMETRY</b>
is a C++ library which
performs certain geometric calculations in 2, 3 and N space.
</p>
<p>
These calculations include angles, areas, containment, distances,
intersections, lengths, and volumes.
</p>
<p>
Some geometric objects can be described in a variety of ways.
For instance, a line has implicit, explicit and parametric
representations. The names of routines often will specify
the representation used, and there are routines to convert
from one representation to another.
</p>
<p>
Another useful task is the delineation of a standard geometric
object. For instance, there is a routine that will return
the location of the vertices of an octahedron, and others to
produce a series of "equally spaced" points on a circle, ellipse,
sphere, or within the interior of a triangle.
</p>
<p>
An open source directory of computational geometry routines is available
at <a href = "http://www.cgal.org/">http://www.cgal.org</a>,
the Computational Geometry Algorithms Library.
</p>
<h3 align = "center">
Licensing:
</h3>
<p>
The computer code and data files described and made available on this web page
are distributed under
<a href = "../../txt/gnu_lgpl.txt">the GNU LGPL license.</a>
</p>
<h3 align = "center">
Languages:
</h3>
<p>
<b>GEOMETRY</b> is available in
<a href = "../../c_src/geometry/geometry.html">a C version</a> and
<a href = "../../cpp_src/geometry/geometry.html">a C++ version</a> and
<a href = "../../f77_src/geometry/geometry.html">a FORTRAN77 version</a> and
<a href = "../../f_src/geometry/geometry.html">a FORTRAN90 version</a> and
<a href = "../../m_src/geometry/geometry.html">a MATLAB version</a>.
</p>
<h3 align = "center">
Related Programs:
</h3>
<p>
<a href = "../../f_src/dutch/dutch.html">
DUTCH</a>,
a FORTRAN90 library which
carries out various computational geometry tasks.
</p>
<p>
<a href = "../../cpp_src/geompack/geompack.html">
GEOMPACK</a>,
a C++ library which
computes the Delaunay triangulation and Voronoi diagram of 2D data.
</p>
<p>
<a href = "../../cpp_src/polygon_moments/polygon_moments.html">
POLYGON_MOMENTS</a>,
a C++ library which
computes arbitrary moments of a polygon.
</p>
<p>
<a href = "../../cpp_src/table_delaunay/table_delaunay.html">
TABLE_DELAUNAY</a>,
a C++ program which
reads a
file of 2d point coordinates and computes the Delaunay triangulation.
</p>
<p>
<a href = "../../cpp_src/tet_mesh/tet_mesh.html">
TET_MESH</a>,
a C++ library which
defines and analyzes
tetrahedral meshes.
</p>
<p>
<a href = "../../cpp_src/tetrahedron_properties/tetrahedron_properties.html">
TETRAHEDRON_PROPERTIES</a>,
a C++ program which
computes properties of a tetrahedron
whose vertex coordinates are read from a file.
</p>
<p>
<a href = "../../datasets/tetrahedrons/tetrahedrons.html">
TETRAHEDRONS</a>,
a dataset directory which
contains examples of tetrahedrons;
</p>
<p>
<a href = "../../datasets/triangles/triangles.html">
TRIANGLES</a>,
a dataset directory which
contains examples of triangles;
</p>
<p>
<a href = "../../c_src/triangulate/triangulate.html">
TRIANGULATE</a>,
a C program which
triangulates a (possibly nonconvex) polygon.
</p>
<p>
<a href = "../../cpp_src/triangulation/triangulation.html">
TRIANGULATION</a>,
a C++ library which
defines and analyzes triangulations.
</p>
<p>
<a href = "../../cpp_src/triangulation_display_opengl/triangulation_display_opengl.html">
TRIANGULATION_DISPLAY_OPENGL</a>,
a C++ program which
reads files defining a triangulation and displays an image
using Open GL.
</p>
<p>
<a href = "../../cpp_src/triangulation_triangle_neighbors/triangulation_triangle_neighbors.html">
TRIANGULATION_TRIANGLE_NEIGHBORS</a>,
a C++ program which
reads data defining a triangulation, determines the neighboring
triangles of each triangle, and writes that information to a file.
</p>
<h3 align = "center">
Reference:
</h3>
<p>
<ol>
<li>
Gerard Bashein, Paul Detmer,<br>
Centroid of a Polygon,<br>
in Graphics Gems IV,<br>
edited by Paul Heckbert,<br>
AP Professional, 1994,<br>
ISBN: 0123361559,<br>
LC: T385.G6974.
</li>
<li>
SF Bockman,<br>
Generalizing the Formula for Areas of Polygons to Moments,<br>
American Mathematical Society Monthly,<br>
Volume 96, Number 2, February 1989, pages 131-132.
</li>
<li>
Adrian Bowyer, John Woodwark,<br>
A Programmer's Geometry,<br>
Butterworths, 1983,<br>
ISBN: 0408012420.
</li>
<li>
Paulo Cezar Pinto Carvalho, Paulo Roma Cavalcanti,<br>
Point in Polyhedron Testing Using Spherical Polygons,<br>
in Graphics Gems V,<br>
edited by Alan Paeth,<br>
Academic Press, 1995,<br>
ISBN: 0125434553,<br>
LC: T385.G6975.
</li>
<li>
Daniel Cohen,<br>
Voxel Traversal along a 3D Line,<br>
in Graphics Gems IV,<br>
edited by Paul Heckbert,<br>
AP Professional, 1994,<br>
ISBN: 0123361559,<br>
LC: T385.G6974.
</li>
<li>
Thomas Cormen, Charles Leiserson, Ronald Rivest,<br>
Introduction to Algorithms,<br>
MIT Press, 2001,<br>
ISBN: 0262032937,<br>
LC: QA76.C662.
</li>
<li>
Marc deBerg, Marc Krevald, Mark Overmars,
Otfried Schwarzkopf,<br>
Computational Geometry,<br>
Springer, 2000,<br>
ISBN: 3-540-65620-0,<br>
LC: QA448.D38.C65.
</li>
<li>
Jack Dongarra, Jim Bunch, Cleve Moler, Pete Stewart,<br>
LINPACK User's Guide,<br>
SIAM, 1979,<br>
ISBN13: 978-0-898711-72-1,<br>
LC: QA214.L56.
</li>
<li>
James Foley, Andries vanDam, Steven Feiner, John Hughes,<br>
Computer Graphics, Principles and Practice,<br>
Second Edition,<br>
Addison Wesley, 1995,<br>
ISBN: 0201848406,<br>
LC: T385.C5735.
</li>
<li>
Martin Gardner,<br>
The Mathematical Carnival,<br>
Knopf, 1975,<br>
ISBN: 0394494067,<br>
LC: QA95.G286.
</li>
<li>
Priamos Georgiades,<br>
Signed Distance From Point To Plane,<br>
in Graphics Gems III,<br>
edited by David Kirk,<br>
Academic Press, 1992,<br>
ISBN: 0124096735,<br>
LC: T385.G6973.
</li>
<li>
Branko Gruenbaum, Geoffrey Shephard,<br>
Pick's Theorem,<br>
The American Mathematical Monthly,<br>
Volume 100, Number 2, February 1993, pages 150-161.
</li>
<li>
John Harris, Horst Stocker,<br>
Handbook of Mathematics and Computational Science,<br>
Springer, 1998,<br>
ISBN: 0-387-94746-9,<br>
LC: QA40.S76.
</li>
<li>
Barry Joe,<br>
GEOMPACK - a software package for the generation of meshes
using geometric algorithms,<br>
Advances in Engineering Software,<br>
Volume 13, 1991, pages 325-331.
</li>
<li>
Anwei Liu, Barry Joe,<br>
Quality Local Refinement of Tetrahedral Meshes Based
on 8-Subtetrahedron Subdivision,<br>
Mathematics of Computation,<br>
Volume 65, Number 215, July 1996, pages 1183-1200.
</li>
<li>
Jack Kuipers,<br>
Quaternions and Rotation Sequences,<br>
Princeton, 1998,<br>
ISBN: 0691102988,<br>
LC: QA196.K85.
</li>
<li>
Robert Miller,<br>
Computing the Area of a Spherical Polygon,<br>
in Graphics Gems IV,<br>
edited by Paul Heckbert,<br>
Academic Press, 1994,<br>
ISBN: 0123361559,<br>
LC: T385.G6974.
</li>
<li>
Albert Nijenhuis, Herbert Wilf,<br>
Combinatorial Algorithms for Computers and Calculators,<br>
Second Edition,<br>
Academic Press, 1978,<br>
ISBN: 0-12-519260-6,<br>
LC: QA164.N54.
</li>
<li>
Atsuyuki Okabe, Barry Boots, Kokichi Sugihara, Sung Nok Chiu,<br>
Spatial Tesselations:
Concepts and Applications of Voronoi Diagrams,<br>
Second Edition,<br>
Wiley, 2000,<br>,
ISBN: 0-471-98635-6,<br>
LC: QA278.2.O36.
</li>
<li>
Joseph ORourke,<br>
Computational Geometry,<br>
Second Edition,<br>
Cambridge, 1998,<br>
ISBN: 0521649765,<br>
LC: QA448.D38.
</li>
<li>
Edward Saff, Arno Kuijlaars,<br>
Distributing Many Points on a Sphere,<br>
The Mathematical Intelligencer,<br>
Volume 19, Number 1, 1997, pages 5-11.
</li>
<li>
Philip Schneider, David Eberly,<br>
Geometric Tools for Computer Graphics,<br>
Elsevier, 2002,<br>
ISBN: 1558605940,<br>
LC: T385.S334.
</li>
<li>
Peter Schorn, Frederick Fisher,<br>
Testing the Convexity of a Polygon,<br>
in Graphics Gems IV,<br>
edited by Paul Heckbert,<br>
AP Professional, 1994,<br>
ISBN: 0123361559,<br>
LC: T385.G6974.
</li>
<li>
Moshe Shimrat,<br>
Algorithm 112:
Position of Point Relative to Polygon,<br>
Communications of the ACM,<br>
Volume 5, Number 8, August 1962, page 434.
</li>
<li>
Kenneth Stephenson,<br>
Introduction to Circle Packing,
The Theory of Discrete Analytic Functions,<br>
Cambridge, 2005,<br>
ISBN: 0521823560,<br>
LC: QA640.7S74.
</li>
<li>
Allen VanGelder,<br>
Efficient Computation of Polygon Area and Polyhedron Volume,<br>
in Graphics Gems V, <br>
edited by Alan Paeth,<br>
AP Professional, 1995,<br>
ISBN: 0125434553,<br>
LC: T385.G6975.
</li>
<li>
Daniel Zwillinger, Steven Kokoska,<br>
Standard Probability and Statistical Tables,<br>
CRC Press, 2000,<br>
ISBN: 1-58488-059-7,<br>
LC: QA273.3.Z95.
</li>
</ol>
</p>
<h3 align = "center">
Source Code:
</h3>
<p>
<ul>
<li>
<a href = "geometry.cpp">geometry.cpp</a>, the source code.
</li>
<li>
<a href = "geometry.hpp">geometry.hpp</a>, the include file.
</li>
<li>
<a href = "geometry.sh">geometry.sh</a>,
commands to compile the source code.
</li>
</ul>
</p>
<h3 align = "center">
Examples and Tests:
</h3>
<p>
<ul>
<li>
<a href = "geometry_prb.cpp">geometry_prb.cpp</a>,
a sample calling program.
</li>
<li>
<a href = "geometry_prb.sh">geometry_prb.sh</a>,
commands to compile and run the sample program.
</li>
<li>
<a href = "geometry_prb_output.txt">geometry_prb_output.txt</a>,
the output file.
</li>
</ul>
</p>
<h3 align = "center">
List of Routines:
</h3>
<p>
<ul>
<li>
<b>ANGLE_BOX_2D</b> "boxes" an angle defined by three points in 2D.
</li>
<li>
<b>ANGLE_CONTAINS_RAY_2D</b> determines if an angle contains a ray, in 2D.
</li>
<li>
<b>ANGLE_DEG_2D</b> returns the angle in degrees swept out between two rays in 2D.
</li>
<li>
<b>ANGLE_HALF_2D</b> finds half an angle in 2D.
</li>
<li>
<b>ANGLE_RAD_2D</b> returns the angle in radians swept out between two rays in 2D.
</li>
<li>
<b>ANGLE_RAD_3D</b> returns the angle between two vectors in 3D.
</li>
<li>
<b>ANGLE_RAD_ND</b> returns the angle between two vectors in ND.
</li>
<li>
<b>ANGLE_TURN_2D</b> computes a turning angle in 2D.
</li>
<li>
<b>ANGLEI_DEG_2D</b> returns the interior angle in degrees between two rays in 2D.
</li>
<li>
<b>ANGLEI_RAD_2D</b> returns the interior angle in radians between two rays in 2D.
</li>
<li>
<b>ANNULUS_AREA_2D</b> computes the area of a circular annulus in 2D.
</li>
<li>
<b>ANNULUS_SECTOR_AREA_2D</b> computes the area of an annular sector in 2D.
</li>
<li>
<b>ANNULUS_SECTOR_CENTROID_2D</b> computes the centroid of an annular sector in 2D.
</li>
<li>
<b>r8_atan</b> computes the inverse tangent of the ratio Y / X.
</li>
<li>
<b>BALL_UNIT_SAMPLE_2D</b> picks a random point in the unit ball in 2D.
</li>
<li>
<b>BALL_UNIT_SAMPLE_3D</b> picks a random point in the unit ball in 3D.
</li>
<li>
<b>BALL_UNIT_SAMPLE_ND</b> picks a random point in the unit ball in ND.
</li>
<li>
<b>BASIS_MAP_3D</b> computes the matrix which maps one basis to another.
</li>
<li>
<b>BOX_01_CONTAINS_POINT_2D</b> reports if a point is contained in the unit box in 2D.
</li>
<li>
<b>BOX_01_CONTAINS_POINT_ND</b> reports if a point is contained in the unit box in ND.
</li>
<li>
<b>BOX_CONTAINS_POINT_2D</b> reports if a point is contained in a box in 2D.
</li>
<li>
<b>BOX_CONTAINS_POINT_ND</b> reports if a point is contained in a box in ND.
</li>
<li>
<b>BOX_RAY_INT_2D:</b> intersection ( box, ray ) in 2D.
</li>
<li>
<b>BOX_SEGMENT_CLIP_2D</b> uses a box to clip a line segment in 2D.
</li>
<li>
<b>CIRCLE_ARC_POINT_NEAR_2D</b> : nearest point on a circular arc.
</li>
<li>
<b>CIRCLE_AREA_2D</b> computes the area of a circle in 2D.
</li>
<li>
<b>CIRCLE_DIA2IMP_2D</b> converts a diameter to an implicit circle in 2D.
</li>
<li>
<b>CIRCLE_EXP_CONTAINS_POINT_2D</b> determines if an explicit circle contains a point in 2D.
</li>
<li>
<b>CIRCLE_EXP2IMP_2D</b> converts a circle from explicit to implicit form in 2D.
</li>
<li>
<b>CIRCLE_IMP_CONTAINS_POINT_2D</b> determines if an implicit circle contains a point in 2D.
</li>
<li>
<b>CIRCLE_IMP_LINE_PAR_INT_2D:</b> ( implicit circle, parametric line ) intersection in 2D.
</li>
<li>
<b>CIRCLE_IMP_POINT_DIST_2D:</b> distance ( implicit circle, point ) in 2D.
</li>
<li>
<b>CIRCLE_IMP_POINT_DIST_SIGNED_2D:</b> signed distance ( implicit circle, point ) in 2D.
</li>
<li>
<b>CIRCLE_IMP_POINT_NEAR_2D:</b> nearest ( implicit circle, point ) in 2D.
</li>
<li>
<b>CIRCLE_IMP_POINTS_2D</b> returns N equally spaced points on an implicit circle in 2D.
</li>
<li>
<b>CIRCLE_IMP_POINTS_3D</b> returns points on an implicit circle in 3D.
</li>
<li>
<b>CIRCLE_IMP_POINTS_ARC_2D</b> returns N points on an arc of an implicit circle in 2D.
</li>
<li>
<b>CIRCLE_IMP_PRINT_2D</b> prints an implicit circle in 2D.
</li>
<li>
<b>CIRCLE_IMP_PRINT_2D</b> prints an implicit circle in 3D.
</li>
<li>
<b>CIRCLE_IMP2EXP_2D</b> converts a circle from implicit to explicit form in 2D.
</li>
<li>
<b>CIRCLE_LLR2IMP_2D</b> converts a circle from LLR to implicit form in 2D.
</li>
<li>
<b>CIRCLE_LUNE_AREA_2D</b> returns the area of a circular lune in 2D.
</li>
<li>
<b>CIRCLE_LUNE_CENTROID_2D</b> returns the centroid of a circular lune in 2D.
</li>
<li>
<b>CIRCLE_PPR2IMP_3D</b> converts a circle from PPR to implicit form in 3D.
</li>
<li>
<b>CIRCLE_PPR2IMP_2D</b> converts a circle from PPR to implicit form in 2D.
</li>
<li>
<b>CIRCLE_SECTOR_AREA_2D</b> computes the area of a circular sector in 2D.
</li>
<li>
<b>CIRCLE_SECTOR_CENTROID_2D</b> returns the centroid of a circular sector in 2D.
</li>
<li>
<b>CIRCLE_SECTOR_CONTAINS_POINT_2D</b> : is a point inside a circular sector?
</li>
<li>
<b>CIRCLE_SECTOR_PRINT_2D</b> prints a circular sector in 2D.
</li>
<li>
<b>CIRCLE_TRIANGLE_AREA_2D</b> returns the area of a circle triangle in 2D.
</li>
<li>
<b>CIRCLE_TRIPLE_ANGLE_2D</b> returns an angle formed by three circles in 2D.
</li>
<li>
<b>CIRCLES_IMP_INT_2D:</b> finds the intersection of two implicit circles in 2D.
</li>
<li>
<b>CONE_AREA_3D</b> computes the surface area of a right circular cone in 3D.
</li>
<li>
<b>CONE_CENTROID_3D</b> returns the centroid of a cone in 3D.
</li>
<li>
<b>CONE_VOLUME_3D</b> computes the volume of a right circular cone in 3D.
</li>
<li>
<b>CONV3D</b> converts 3D data to a 2D projection.
</li>
<li>
<b>COS_DEG</b> returns the cosine of an angle given in degrees.
</li>
<li>
<b>COT_DEG</b> returns the cotangent of an angle given in degrees.
</li>
<li>
<b>COT_RAD</b> returns the cotangent of an angle.
</li>
<li>
<b>CSC_DEG</b> returns the cosecant of an angle given in degrees.
</li>
<li>
<b>CUBE_SHAPE_3D</b> describes a cube in 3D.
</li>
<li>
<b>CUBE_SIZE_3D</b> gives "sizes" for a cube in 3D.
</li>
<li>
<b>CYLINDER_POINT_DIST_3D</b> determines the distance from a cylinder to a point in 3D.
</li>
<li>
<b>CYLINDER_POINT_DIST_SIGNED_3D:</b> signed distance from cylinder to point in 3D.
</li>
<li>
<b>CYLINDER_POINT_INSIDE_3D</b> determines if a cylinder contains a point in 3D.
</li>
<li>
<b>CYLINDER_POINT_NEAR_3D:</b> nearest point on a cylinder to a point in 3D.
</li>
<li>
<b>CYLINDER_SAMPLE_3D</b> samples a cylinder in 3D.
</li>
<li>
<b>CYLINDER_VOLUME_3D</b> determines the volume of a cylinder in 3D.
</li>
<li>
<b>DEGREES_TO_RADIANS</b> converts an angle from degrees to radians.
</li>
<li>
<b>DGE_DET</b> computes the determinant of a matrix factored by SGE_FA.
</li>
<li>
<b>DGE_FA</b> factors a general matrix.
</li>
<li>
<b>DGE_SL</b> solves a system factored by SGE_FA.
</li>
<li>
<b>DIRECTION_PERT_3D</b> randomly perturbs a direction vector in 3D.
</li>
<li>
<b>DIRECTION_UNIFORM_2D</b> picks a random direction vector in 2D.
</li>
<li>
<b>DIRECTION_UNIFORM_3D</b> picks a random direction vector in 3D.
</li>
<li>
<b>DIRECTION_UNIFORM_ND</b> generates a random direction vector in ND.
</li>
<li>
<b>DISK_POINT_DIST_3D</b> determines the distance from a disk to a point in 3D.
</li>
<li>
<b>DMS_TO_RADIANS</b> converts an angle from degrees/minutes/seconds to radians.
</li>
<li>
<b>DODEC_SHAPE_3D</b> describes a dodecahedron in 3D.
</li>
<li>
<b>DODEC_SIZE_3D</b> gives "sizes" for a dodecahedron in 3D.
</li>
<li>
<b>DUAL_SHAPE_3D</b> constructs the dual of a shape in 3D.
</li>
<li>
<b>DUAL_SIZE_3D</b> determines sizes for a dual of a shape in 3D.
</li>
<li>
<b>ELLIPSE_AREA_2D</b> returns the area of an ellipse in 2D.
</li>
<li>
<b>ELLIPSE_POINT_DIST_2D</b> finds the distance from a point to an ellipse in 2D.
</li>
<li>
<b>ELLIPSE_POINT_NEAR_2D</b> finds the nearest point on an ellipse in 2D.
</li>
<li>
<b>ELLIPSE_POINTS_2D</b> returns N points on an tilted ellipse in 2D.
</li>
<li>
<b>ELLIPSE_POINTS_ARC_2D</b> returns N points on a tilted elliptical arc in 2D.
</li>
<li>
<b>ENORM0_ND</b> computes the Euclidean norm of a (X-Y) in N space.
</li>
<li>
<b>GET_SEED</b> returns a random seed for the random number generator.
</li>
<li>
<b>GLOB2LOC_3D</b> converts from a global to a local coordinate system in 3D.
</li>
<li>
<b>HALFPLANE_CONTAINS_POINT_2D</b> reports if a half-plane contains a point in 2d.
</li>
<li>
<b>HALFSPACE_IMP_TRIANGLE_INT_3D:</b> intersection ( implicit halfspace, triangle ) in 3D.
</li>
<li>
<b>HALFSPACE_NORM_TRIANGLE_INT_3D:</b> intersection ( normal halfspace, triangle ) in 3D.
</li>
<li>
<b>HALFSPACE_TRIANGLE_INT_3D:</b> intersection ( halfspace, triangle ) in 3D.
</li>
<li>
<b>HAVERSINE</b> computes the haversine of an angle.
</li>
<li>
<b>HELIX_SHAPE_3D</b> computes points on a helix in 3D.
</li>
<li>
<b>HEXAGON_AREA_2D</b> returns the area of a regular hexagon in 2D.
</li>
<li>
<b>HEXAGON_CONTAINS_POINT_2D</b> finds if a point is inside a hexagon in 2D.
</li>
<li>
<b>HEXAGON_SHAPE_2D</b> returns points on the unit regular hexagon in 2D.
</li>
<li>
<b>HEXAGON_UNIT_AREA_2D</b> returns the area of a unit regular hexagon in 2D.
</li>
<li>
<b>HEXAGON_VERTICES_2D</b> returns the vertices of the unit hexagon in 2D.
</li>
<li>
<b>I4_DEDEKIND_FACTOR</b> computes a function needed for a Dedekind sum.
</li>
<li>
<b>I4_DEDEKIND_SUM</b> computes the Dedekind sum of two I4's.
</li>
<li>
<b>I4_FACTORIAL2</b> computes the double factorial function N!!
</li>
<li>
<b>I4_GCD</b> finds the greatest common divisor of two I4's.
</li>
<li>
<b>I4_LCM</b> computes the least common multiple of two I4's.
</li>
<li>
<b>I4_MAX</b> returns the maximum of two I4's.
</li>
<li>
<b>I4_MIN</b> returns the smaller of two I4's.
</li>
<li>
<b>I4_MODP</b> returns the nonnegative remainder of I4 division.
</li>
<li>
<b>I4_SIGN</b> returns the sign of an I4.
</li>
<li>
<b>I4_SWAP</b> switches two I4's.
</li>
<li>
<b>I4_UNIFORM</b> returns a scaled pseudorandom I4.
</li>
<li>
<b>I4_WRAP</b> forces an I4 to lie between given limits by wrapping.
</li>
<li>
<b>I4COL_COMPARE</b> compares columns I and J of an I4COL
</li>
<li>
<b>I4COL_FIND_ITEM</b> searches an I4COL for a given value.
</li>
<li>
<b>I4COL_FIND_PAIR_WRAP</b> wrap searches an I4COL for a pair of items.
</li>
<li>
<b>I4COL_SORT_A</b> ascending sorts the columns of an integer array.
</li>
<li>
<b>I4COL_SORTED_UNIQUE_COUNT</b> counts unique elements in an ICOL array.
</li>
<li>
<b>I4COL_SWAP</b> swaps two columns of an integer array.
</li>
<li>
<b>I4MAT_PRINT</b> prints an I4MAT, with an optional title.
</li>
<li>
<b>I4MAT_PRINT_SOME</b> prints some of an I4MAT.
</li>
<li>
<b>I4MAT_TRANSPOSE_PRINT</b> prints an I4MAT, transposed.
</li>
<li>
<b>I4MAT_TRANSPOSE_PRINT_SOME</b> prints some of an I4MAT, transposed.
</li>
<li>
<b>I4ROW_COMPARE</b> compares two rows of an I4ROW.
</li>
<li>
<b>I4ROW_SORT_A</b> ascending sorts the rows of an I4ROW.
</li>
<li>
<b>I4ROW_SWAP</b> swaps two rows of an I4ROW.
</li>
<li>
<b>I4VEC_COPY</b> copies an I4VEC.
</li>
<li>
<b>I4VEC_HEAP_D</b> reorders an I4VEC into a descending heap.
</li>
<li>
<b>I4VEC_INDICATOR_NEW</b> sets an I4VEC to the indicator vector.
</li>
<li>
<b>I4VEC_LCM</b> returns the least common multiple of an I4VEC.
</li>
<li>
<b>I4VEC_PRINT</b> prints an I4VEC.
</li>
<li>
<b>I4VEC_PRODUCT</b> multiplies the entries of an I4VEC.
</li>
<li>
<b>I4VEC_REVERSE</b> reverses the elements of an I4VEC.
</li>
<li>
<b>I4VEC_SORT_HEAP_A</b> ascending sorts an I4VEC using heap sort.
</li>
<li>
<b>I4VEC_SORTED_UNIQUE</b> finds unique elements in a sorted I4VEC.
</li>
<li>
<b>I4VEC_UNIFORM_NEW</b> returns a scaled pseudorandom I4VEC.
</li>
<li>
<b>I4VEC_ZERO</b> zeroes an I4VEC.
</li>
<li>
<b>I4VEC2_COMPARE</b> compares pairs of integers stored in two vectors.
</li>
<li>
<b>I4VEC2_SORT_A</b> ascending sorts a vector of pairs of integers.
</li>
<li>
<b>I4VEC2_SORTED_UNIQUE</b> finds unique elements in a sorted I4VEC2.
</li>
<li>
<b>ICOS_SHAPE</b> describes a icosahedron.
</li>
<li>
<b>ICOS_SIZE</b> gives "sizes" for an icosahedron.
</li>
<li>
<b>LINE_EXP_IS_DEGENERATE_ND</b> finds if an explicit line is degenerate in ND.
</li>
<li>
<b>LINE_EXP_NORMAL_2D</b> computes the unit normal vector to a line in 2D.
</li>
<li>
<b>LINE_EXP_PERP_2D</b> computes a line perpendicular to a line and through a point.
</li>
<li>
<b>LINE_EXP_POINT_DIST_2D:</b> distance ( explicit line, point ) in 2D.
</li>
<li>
<b>LINE_EXP_POINT_DIST_3D:</b> distance ( explicit line, point ) in 3D.
</li>
<li>
<b>LINE_EXP_POINT_DIST_SIGNED_2D:</b> signed distance ( explicit line, point ) in 2D.
</li>
<li>
<b>LINE_EXP_POINT_NEAR_2D</b> computes the point on an explicit line nearest a point in 2D.
</li>
<li>
<b>LINE_EXP_POINT_NEAR_3D:</b> nearest point on explicit line to point in 3D.
</li>
<li>
<b>LINE_EXP2IMP_2D</b> converts an explicit line to implicit form in 2D.
</li>
<li>
<b>LINE_EXP2PAR_2D</b> converts a line from explicit to parametric form in 2D.
</li>
<li>
<b>LINE_EXP2PAR_3D</b> converts an explicit line into parametric form in 3D.
</li>
<li>
<b>LINE_IMP_IS_DEGENERATE_2D</b> finds if an implicit point is degenerate in 2D.
</li>
<li>
<b>LINE_IMP_POINT_DIST_2D:</b> distance ( implicit line, point ) in 2D.
</li>
<li>
<b>LINE_IMP_POINT_DIST_SIGNED_2D:</b> signed distance ( implicit line, point ) in 2D.
</li>
<li>
<b>LINE_IMP2EXP_2D</b> converts an implicit line to explicit form in 2D.
</li>
<li>
<b>LINE_IMP2PAR_2D</b> converts an implicit line to parametric form in 2D.
</li>
<li>
<b>LINE_PAR_POINT_DIST_2D:</b> distance ( parametric line, point ) in 2D.
</li>
<li>
<b>LINE_PAR_POINT_DIST_3D:</b> distance ( parametric line, point ) in 3D.
</li>
<li>
<b>LINE_PAR_POINT_NEAR_2D:</b> nearest point on parametric line to point in 2D.
</li>
<li>
<b>LINE_PAR_POINT_DIST_3D:</b> distance ( parametric line, point ) in 3D.
</li>
<li>
<b>LINE_PAR2EXP_2D</b> converts a parametric line to explicit form in 2D.
</li>
<li>
<b>LINE_PAR2EXP_2D</b> converts a parametric line to explicit form in 3D.
</li>
<li>
<b>LINE_PAR2IMP_2D</b> converts a parametric line to implicit form in 2D.
</li>
<li>
<b>LINES_EXP_ANGLE_3D</b> finds the angle between two explicit lines in 3D.
</li>
<li>
<b>LINES_EXP_ANGLE_ND</b> returns the angle between two explicit lines in ND.
</li>
<li>
<b>LINES_EXP_DIST_3D</b> computes the distance between two explicit lines in 3D.
</li>
<li>
<b>LINES_EXP_DIST_3D_2</b> computes the distance between two explicit lines in 3D.
</li>
<li>
<b>LINES_EXP_EQUAL_2D</b> determines if two explicit lines are equal in 2D.
</li>
<li>
<b>LINES_EXP_INT_2D</b> determines where two explicit lines intersect in 2D.
</li>
<li>
<b>LINES_EXP_NEAR_3D</b> computes nearest points on two explicit lines in 3D.
</li>
<li>
<b>LINES_EXP_PARALLEL_2D</b> determines if two lines are parallel in 2D.
</li>
<li>
<b>LINES_EXP_PARALLEL_3D</b> determines if two lines are parallel in 3D.
</li>
<li>
<b>LINES_IMP_ANGLE_2D</b> finds the angle between two implicit lines in 2D.
</li>
<li>
<b>LINES_IMP_DIST_2D</b> determines the distance between two implicit lines in 2D.
</li>
<li>
<b>LINES_IMP_INT_2D</b> determines where two implicit lines intersect in 2D.
</li>
<li>
<b>LINES_PAR_ANGLE_2D</b> finds the angle between two parametric lines in 2D.
</li>
<li>
<b>LINES_PAR_ANGLE_3D</b> finds the angle between two parametric lines in 3D.
</li>
<li>
<b>LINES_PAR_DIST_3D</b> finds the distance between two parametric lines in 3D.
</li>
<li>
<b>LINES_PAR_INT_2D</b> determines where two parametric lines intersect in 2D.
</li>
<li>
<b>LOC2GLOB_3D</b> converts from a local to global coordinate system in 3D.
</li>
<li>
<b>LVEC_PRINT</b> prints a logical vector.
</li>
<li>
<b>MINABS</b> finds a local minimum of F(X) = A * abs ( X ) + B.
</li>
<li>
<b>MINQUAD</b> finds a local minimum of F(X) = A * X^2 + B * X + C.
</li>
<li>
<b>OCTAHEDRON_SHAPE_3D</b> describes an octahedron in 3D.
</li>
<li>
<b>OCTAHEDRON_SIZE_3D</b> returns size information for an octahedron in 3D.
</li>
<li>
<b>PARABOLA_EX</b> finds the extremal point of a parabola determined by three points.
</li>
<li>
<b>PARABOLA_EX2</b> finds the extremal point of a parabola determined by three points.
</li>
<li>
<b>PARALLELOGRAM_AREA_2D</b> computes the area of a parallelogram in 2D.
</li>
<li>
<b>PARALLELOGRAM_AREA_3D</b> computes the area of a parallelogram in 3D.
</li>
<li>