In Part 1 of this series (see ” Accessing Spatial Data, Part 1” in the December 1997 issue), David provided the routines for determining whether two lines intersect. In Part 2, he completes the spatial data toolset with the functions for area.
In last month’s article, I showed you how to use Access with geographical data. I then went on to describe a Line Intersection function as one of the primary tools for working with spatial data. In this month’s article, I’ll spend a little time looking at some more data represent-ations before going on to two further functions: one to calculate areas, and one to determine whether or not a point lies within a defined area.