
7
Correlation
This chapter deals with measuring dependence betwe en points in a point pattern, using the concept
of c orrelation.
7.1 Introduction
Often the motivation for analysing point pattern data is to determine whether the points appe ar
to have been placed independently of each other, or whether they exhibit some kind of inter point
dependence.
Figure 7.1 shows th ree archetypal point patter ns repr esenting ‘regularity’ (where points tend to
avoid each oth er), ‘independence ’ (complete spatial randomness), and ‘clustering’ (where points
tend to be close tog ether).
Figure 7.1. Classical trichotomy between regular (Left), independent (Middle), ...