Circle fitting using modified Coopes method

Robust method for fitting a circle to data using Weighted Linear Least Squares.

Description

The included function 'ciclefit' estimates the radius and center of a circle represented by data-points.
This is achieved using a modified version of Coopes method(Coope, I. D.,Circle Fitting by Linear and Nonlinear Least Squares, 1993. http://link.springer.com/article/10.1007%2FBF00939613 ) which yields robust results comparable to the Total Least Squares approach while using only a (directly solvable) Linear Least Squares. It has been modified to use weights for the data points (thus using Weighted Linear Least Squares).

That modification has been added to enable a fast and robust estimate of the (causal) curvature of a given path.

Included is a quick demonstration (circfit_DEMO.m) that showcases general circle fitting and how to use that to estimate curvature.

• MATLAB release: MATLAB 8.0 (R2012b)