**triangle_grid**,
a FORTRAN90 code which
generates a grid of points
over the interior of a triangle in 2D.

Starting with any 3 points A, B, and C that define a triangle, we can divide each side of the triangle into N subintervals, and create a triangular grid. This defines ((N+1)*(N+2))/2 points that lie on the intersections of grid lines. The arrangement is suggested by this diagram:

X 9 X 8 9 X 7 8 9 X 6 7 8 9 X 5 6 7 8 9 X 4 5 6 7 8 9 X 3 4 5 6 7 8 9 X 2 3 4 5 6 7 8 9 X 1 2 3 4 5 6 7 8 9 X 0 1 2 3 4 5 6 7 8 9 X

The library includes a routine which allows the user to pick an arbitrary triangle and an arbitrary number of subdivisions. It then returns the triangular gridpoints defined by that choice.

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

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

BALL_GRID, a FORTRAN90 code which computes a grid of points over the interior of a ball in 3D.

CIRCLE_ARC_GRID, a FORTRAN90 code which computes points equally spaced along a circular arc;

CUBE_GRID, a FORTRAN90 code which computes a grid of points over the interior of a cube in 3D.

DISK_GRID, a FORTRAN90 code which computes a grid of points over the interior of a disk in 2D.

ELLIPSE_GRID, a FORTRAN90 code which computes a grid of points over the interior of an ellipse in 2D.

ELLIPSOID_GRID, a FORTRAN90 code which computes a grid of points over the interior of an ellipsoid in 3D.

HYPERCUBE_GRID, a FORTRAN90 code which computes a grid of points over the interior of a hypercube in M dimensions.

LINE_GRID, a FORTRAN90 code which computes a grid of points over the interior of a line segment in 1D.

POLYGON_GRID, a FORTRAN90 code which generates a grid of points over the interior of a polygon in 2D.

PYRAMID_GRID, a FORTRAN90 code which computes a grid of points over the interior of the unit pyramid in 3D;

SIMPLEX_GRID, a FORTRAN90 code which generates a grid of points over the interior of a simplex in M dimensions.

SPHERE_CUBED_GRID, a FORTRAN90 code which uses the projection of a cube to create grids of points, lines, and quadrilaterals on the surface of the unit sphere in 3D.

SPHERE_FIBONACCI_GRID, a FORTRAN90 code which uses a Fibonacci spiral to create a grid of points on the surface of the unit sphere in 3D.

SPHERE_GRID, a FORTRAN90 code which provides a number of ways of generating grids of points, or of points and lines, or of points and lines and faces, on the surface of the unit sphere in 3D.

SPHERE_LLQ_GRID, a FORTRAN90 code which uses longitudes and latitudes to create grids of points, lines, and quadrilaterals on the surface of the unit sphere in 3D.

SPHERE_LLT_GRID, a FORTRAN90 code which uses longitudes and latitudes to create grids of points, lines, and triangles on the surface of the unit sphere in 3D.

TETRAHEDRON_GRID, a FORTRAN90 code which computes a grid of points over the interior of a tetrahedron in 3D.

WEDGE_GRID, a FORTRAN90 code which computes a grid of points over the interior of the unit wedge in 3D.

- triangle_grid.f90, the source code.
- triangle_grid.sh, compiles the source code.