Versión (4.19 KB) por Ohad Gal
Find the best fit for an ellipse using a given set of points (a closed contour).

33.2K descargas

Actualizado 2 Oct 2003

Ver licencia

This function uses the Least-Squares criterion for estimation of the best fit to an ellipse from a given set of points (x,y). The LS estimation is done for the conic representation of an ellipse (with a possible tilt).

Conic Ellipse representation = a*x^2+b*x*y+c*y^2+d*x+e*y+f=0
(Tilt/orientation for the ellipse occurs when the term x*y exists (i.e. b ~= 0))

Later, after the estimation, the tilt is removed from the ellipse (using a rotation matrix) and then, the rest of the parameters which describes an ellipse are extracted from the conic representation.

For debug purposes, the estimation can be drawn on top of a given axis handle.

1) This function does not work on a three-dimensional axis system. (only 2D)
2) At least 5 points are needed in order to estimate the 5 parameters of the ellipse.
3) If the data is a hyperbola or parabula, the function return empty fields and a status indication

Citar como

Ohad Gal (2023). fit_ellipse (, MATLAB Central File Exchange. Recuperado .

Compatibilidad con la versión de MATLAB
Se creó con R12.1
Compatible con cualquier versión
Compatibilidad con las plataformas
Windows macOS Linux

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!
Versión Publicado Notas de la versión

1. added a test to identify if the data is a hyperbola or parabola - returned in the "status" field
2. the routine finds now the center point of the original (tilted) ellipse as well (fields "X0_in","Y0_in")