In this chapter we apply the general methods surveyed and developed in Chapter 6 to the problem of fitting circles to data.

7.1 Error analysis of geometric circle fit

First we analyze the geometric circle fit, i.e., the estimator Θˆ = (aˆ, bˆ, Rˆ) of the circle parameters (the center (a,b) and the radius R) minimizing ∑d2i , where di is the orthogonal (geometric) distance from the data point (xi,yi) to the fitted circle.