From: David Eppstein <eppstein@ics.uci.edu>
Subject: Re: Circle around points ?
Date: Fri, 02 Feb 2001 17:51:01 -0800
Newsgroups: sci.math
Summary: Bounding circles in R^2

> > How would you find the centre and radius of the smallest circle which
> > encloses a set of points in (x,y) format ?
> > Neil Bennett - neilb@texas.net - 200102021715

Use Bernd Gärtner's miniball code... 
http://www.inf.ethz.ch/personal/gaertner/miniball.html

If by "how" you mean you want to have some idea how it works, you can try 
his paper 
http://www.inf.ethz.ch/personal/gaertner/texts/own_work/esa99_final.ps.gz
-- 
David Eppstein       UC Irvine Dept. of Information & Computer Science
eppstein@ics.uci.edu http://www.ics.uci.edu/~eppstein/