bootEllipse {fitConic}

Simple, Medium-Quality Ellipse Fitting Function

Description

This function generates a half-decent fit to the source data. It is intended only for internal use, to bootstrap the higher-quality fitConic function.

Usage

bootEllipse(x, y = NULL, ...)

Arguments

x

vector of x-values, or a Nx2 array of x and y values. In the latter case, the input y is ignored.

y

vector of y-values.

...

possible other arguments to be passed to future upgrades

Details

This can be used as a Q&D ellipse fitting algorithm, but is intended only for internal use by fitConic, providing that function with an initial estimate for the ellipse's defining parameter set.

Value

parA

6-element set with estimate of the "ABCDEF" coefficients for the general quadratic equation

centroid

estimate of the ellipse's centroid

Author(s)

Carl Witthoft, [e-mail]

References

This is a revision of the function EllipseDirectFit in package conicfit by Jose Gama, with minor upgrades. Original MATLAB code by: Nikolai Chernov https://www.mathworks.com/matlabcentral/fileexchange/22684-ellipse-fit-direct-method A. W. Fitzgibbon, M. Pilu, R. B. Fisher, "Direct Least Squares Fitting of Ellipses", IEEE Trans. PAMI, Vol. 21, pages 476-480 (1999) Halir R, Flusser J (1998) Proceedings of the 6th International Conference in Central Europe on Computer Graphics and Visualization, Numerically stable direct least squares fitting of ellipses (WSCG, Plzen, Czech Republic), pp 125132.

See Also

fitConic , createConic