ABSTRACT
Computer software is generally designed to undertake particular tasks or to solve problems. Geographic Information Systems (GIS) are no exception, and of course in this case the tasks or problems involve spatial data. 0ne of the most intriguing things about spatial data problems is that things which appear to be trivially easy to a human being can be surprisingly difficult on a computer. This is partly due to the complex nature of spatial data, and partly to the way that computers tackle problems.
