
264 Data Analysis and Statistics for Geography, Environmental Science, and Engineering
k
mT
T
=
−
/
/
2
2
(8.9)
and p is the probability that a cell contains a point
p
k
mT
k
==
/
(8.10)
The mean is the rate m/T. We then use chi-square to test if pattern distributed according to a nega-
tive binomial.
For example, suppose we have T = 3 × 3 = 9 cells and that we observe m = 13 points. The rate
is m/T = 13/9 = 1.44. Suppose we observe the following counts in each cell 1, 0, 1, 0, 1, 5, 2, 2, 1.
Therefore, the observed values of number of cells with r = 0, 1, 2, 3, 4, 5 are 2, 4, 2, 0, 0, 1. The
variance is calculated to be s
2
= 2.27. Therefore, the clus ...