Preprint #97-3



Analysis of Spatial Point Patterns Using Bundles of Product Density Lisa Functions

by

Linda Brant Collins and Noel Cressie


Abstract

The analysis of a spatial point pattern is often involved with looking for structure, such as clustering or regularity. This can be done through (kernel density) estimates of the K-function or its derivative, the product density function. In this article, we define a local version of the product density function for each event derived under Anselin's (1995) definition of a local indicator of spatial association (LISA). These product density LISA functions are then grouped by a standard hierarchical clustering algorithm into bundles of functions with similar behavior. Events corresponding to LISA functions within the same bundle are similar with respect to their distance to other nearby events. This grouping of events is very different from the usual clustering notion in spatial point patterns. Our research provides a new quantification of structure in the analysis of spatial point patterns.


Copies of preprints are available from the author upon request. Use the preprint number (located at the top of the page) and make the request directly to the author, Iowa State University, Department of Statistics, Snedecor Hall, Ames, IA 50011-1210.