miniball - Smallest enclosing ball

Hi all,

the appended algorithm solves a common problem in computational
geometry.  It determines the (euclidian) center and radius of the
smallest enclosing ball of a set of n points in d dimensions.

Example: 50 random points in 5 dimensions

octave:1> a=randn(5,50); [c,r]=miniball(a)
c =

  -0.491455
   0.475413
  -0.685300
   0.096564
  -0.164695

r = 3.3357

I hereby release the code under the GPL for inclusion in a future
release of octave-(forge).

Comments are welcome.

Have fun,
-Harald