## About the picture

This is the Voronoi diagram of a set of points, using a
distance
function determined by a convex quadrilateral, as computed by an
applet written by Lihong
Ma at FernUniversität Hagen. The
applet maintains the Voronoi diagram as either sites (the black points in the diagram)
or vertices of the unit ball are interactively inserted, deleted, and moved around. I
added the colors myself; since the Voronoi diagram is a planar map, I only needed four
colors to ensure that adjacent Voronoi regions are colored differently.

CS 497 (Spring 2000) -
Jeff Erickson
(jeffe@cs.uiuc.edu)
19 Nov 1999