correspondence with X reveal keyword "data structure"

What-if analysis for point data sets using generalised Voronoi diagrams http://www.geocomputation.org/2000/GC049/Gc049.htm

http://www-numi.fnal.gov/HyperNews/get/software_discussion/9.html
http://www.cg.tuwien.ac.at/studentwork/CESCG99/RCuk/datStr_Vor.htm
http://www.geom.umn.edu/software/cglist/lowdvod.html