FORTRAN PROGRAM FOR THE ANALYSIS OF POINT PATTERNS WITH CORRECTION FOR EDGE EFFECTS

A FORTRAN program is presented for an algorithm to calculate Ripley's K(r) estimator for n points within a study region with an irregularly shaped boundary. When the boundary is digitized in vector mode, the re sult is a polygon consisting of a sequence of m straightline segments (sides). Each estimate of K(r) is computed from a single set of result s obtained after n(n - 1)m operations. Examples of application are con cerned with the clustering of wildcat wells in Canadian oil and gas pl ays. It is shown that oil discovery wells in the Devonian Beaverhill L ake Play, Central Alberta, are positively clustered. Strong deviations from randomness are exhibited by wildcats and gas discoveries in the Leduc Reef Complex-Windfall Play in the same region. The dataset for t he latter example is relatively large, consisting of n = 249 points wi thin a polygon with m = 264 sides.