TOMS112
Point in Polygon

TOMS112 is a FORTRAN90 library which determines whether a point is inside a polygon.

Licensing:

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

Languages:

TOMS112 is available in a C version and a C++ version and a FORTRAN90 version and a MATLAB version and a Python version.

Related Software and Data:

GEOMETRY, a FORTRAN90 library which performs geometric calculations in 2, 3 and N dimensional space.

POLYGON_MONTE_CARLO, a FORTRAN90 library which applies a Monte Carlo method to estimate the integral of a function over the interior of a polygon in 2D.

POLYGON_PROPERTIES, a FORTRAN90 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.

POLYGON_TRIANGULATE, a FORTRAN90 library which triangulates a possibly nonconvex polygon, and which can use gnuplot to display the external edges and internal diagonals of the triangulation.

Reference:

1. Moshe Shimrat,
   Algorithm 112: Position of Point Relative to Polygon,
   Communications of the ACM,
   Volume 5, Number 8, August 1962, page 434.

Source Code:

• toms112.f90, the source code.

Examples and Tests:

• toms112_test.f90, a sample calling program.
• toms112_test.txt, the output file.

List of Routines:

• POINT_IN_POLYGON determines if a point is inside a polygon
• R8VEC2_PRINT prints an R8VEC2.
• TIMESTAMP prints the current YMDHMS date as a time stamp.

You can go up one level to the FORTRAN90 source codes.