ellipse
ellipse,
an Octave code which
carries out geometric calculations for ellipses and ellipsoids, including
area, distance to a point, eccentricity, perimeter, points along the
perimeter, random sampling, conversion between standard and quadratic forms.
Licensing:
The computer code and data files described and made available on this web page
are distributed under
the GNU LGPL license.
Languages:
ellipse is available in
a C version and
a C++ version and
a Fortran90 version and
a MATLAB version and
an Octave version and
a Python version.
Related Programs:
ellipse_test
geometry,
a MATLAB code which
performs geometric calculations in 2, 3 and M dimensional space,
including the computation of angles, areas, containment, distances,
intersections, lengths, and volumes.
Source code:

ellipse_area1.m,
returns the area of an ellipse x'*A*x=r^2;

ellipse_area2.m,
returns the area of an ellipse ax^2+bxy+cy^2=d;

ellipse_area3.m,
returns the area of an ellipse (x/r1)^2+(y/r2)^2=1;

ellipse_aspect_ratio.m,
returns the aspect ratio of an ellipse (x/a)^2+(y/b)^2=1;

ellipse_ecentricity.m,
returns the eccentricity of an ellipse (x/a)^2+(y/b)^2=1;

ellipse_flattening.m,
returns the flattening of an ellipse (x/a)^2+(y/b)^2=1;

ellipse_perimeter.m,
returns the perimeter of an ellipse (x/a)^2+(y/b)^2=1;

ellipse_point_dist_2d.m,
returns the distance to an ellipse in 2D;

ellipse_point_near_2d.m,
returns the nearest point on an ellipse in 2D;

ellipse_points_2d.m,
returns points on an ellipse in 2D;

ellipse_points_arc_2d.m,
returns points on an elliptical arc;

ellipse_quadratic_to_standard.m,
converts the formula for an ellipse from quadratic to standard form.

ellipse_standard_to_quadratic.m,
converts the formula for an ellipse from standard to quadratic form.

ellipsoid_area.m,
returns the surface area of an ellipsoid.

elliptic_inc_em.m
evaluates the incomplete elliptic integral E(PHI,M).

elliptic_inc_fm.m
evaluates the incomplete elliptic integral F(PHI,M).

r8_modp.m,
returns the positive remainder of R8 division;

r8_sign.m,
returns the sign of an R8;

rd.m
computes an incomplete elliptic integral of the second kind, RD(X,Y,Z).

rf.m
computes an incomplete elliptic integral of the first kind, RF(X,Y,Z).
Last revised on 14 October 2022.