AN ANSI-C PROGRAM TO DETERMINE IN EXPECTED LINEAR TIME THE VERTICES OF THE CONVEX-HULL OF A SET OF PLANAR POINTS

A convex polygon is one where any line connecting any two points within the polygon must lie entirely within the polygon. The convex hull of a set of planar data points is defined as the smallest such polygon containing all the data points. The convex hull may be used to define the area where values may be interpolated as opposed to extrapolated from the original data points. For example, it may be used to define the area within which it is valid to contour or krige. This paper presents algorithms and code to partition a set of planar data points into rectangular boxes and then determine the vertices of their convex hull in expected linear time.