Contained within is a lightweight quadtree implementation.  It was originally 
intended io improve performance with a ruby-gnome app but also works standalone.

Usage:

QuadTreeAccelerator is the most interesting class.  Given a set of points,
it'll partition the points in a quad-tree,ie,

qball = QuadTreeAccelerator.new(myObjectArray)

Atm, only point-like objects are supported :/  So the objects must respond 
to x, y, z and id messages (see UniquePoint3). For example, in IRB:

require 'quad_tree_accelerator'
ps = (1..100).map{|x| UniquePoint3.new(rand(1000),rand(1000),rand(1000))};nil
qball = QuadTreeAccelerator.new(ps);nil
puts qball

The accelerator includes methods for manipulating the tree contents,
iterating over points/nodes and queries.

Tests are included and run via run_tests.rb

daniel.g