Geometric algorithm sought

Hi, my problem is directly isomorphic to the three dimensional closest

neighbor problem from geometry. So far I have used brute force and it

is not so bad on the typical small data set, but even so the delay is

noticeable. Is there something like a canned 3D-tree Perl

implementation? Randall: I _have_ searched CPAN this time.

--

Ian Zimmerman, Oakland, California, U.S.A.

In his own soul a man bears the source

from which he draws all his sorrows and his joys.

Sophocles.