Fitting a Circle to a Given Set of Points

Date: 08/12/2005 at 12:03:21
From: Jessica
Subject: circular regression

Given a set of points how do you calculate the circle of best fit?  In
other words, if you were given a set of points how would you find the
center and radius, or the equation for the circle of best fit?  Is
there a way to do it on Excel or the graphing calculator?

I believe it has something to do with the least squares method and the
distance formula.  I have found some programs you can purchase to
calculate it, but I was curious on the method.

Date: 08/12/2005 at 13:56:09
From: Doctor George
Subject: Re: circular regression

Hi Jessica,

Thanks for writing to Doctor Math.  This link has an excellent paper 
on fitting curves, including least squares circles:

     http://nvl.nist.gov/pub/nistpubs/jres/103/6/j36sha.pdf 

Write again if you need more help.

- Doctor George, The Math Forum
  http://mathforum.org/dr.math/