Barr's "superquadrics" ellipsoid.
[x,y,z] = SUPERQUAD(n,e,m) is a generalized ellipsoid with
n = vertical roundness, e = horizontal roundness and m facets.
If values of n and e are not given, random values are supplied.
The default value of m is 24.
SUPERQUAD(...) , with no output arguments, does a SURF plot.
Ref: A. H. Barr, IEEE Computer Graphics and Applications, 1981,
or, Graphics Gems III, David Kirk, editor, 1992.
See also: SQDEMO .