Table 3 R index, standard error of expected mean, s, and z statistic [13] for the data sets used. When the pattern is entirely random R = 1, if the events are uniform then R > 1 (R = 2.149 for a perfect hexagonal uniform distribution) and conversely when the population of events is clumped R < 1 (R approaches 0 for maximally clumped distribution). The z test statistic considers the null hypothesis that the spatial distribution is random. Data sets comparable to those generated in [1] in italics.
Dataset | R | s | z | Pattern |
|---|---|---|---|---|
Hexagonal | 2.15 | 0.003 | 76.53 | Uniform |
Rice 3 | 1.41 | 0.002 | 39.57 | Uniform |
PG 92 | 1.36 | 0.067 | 6.16 | Uniform |
Bee-eater | 1.34 | 0.086 | 8.17 | Uniform |
PG 93 | 1.3 | 0.077 | 4.9 | Uniform |
Uniform | 1.25 | 0.003 | 17.34 | Uniform |
Rice 1 | 1.08 | 0.004 | 6.12 | Uniform |
Rice 5 | 1.04 | 0.016 | 0.99 | Random |
Poisson | 0.98 | 0.003 | -1.1 | Random |
Rice 4 | 0.94 | 0.013 | -1.59 | Random |
Xanth | 0.89 | 0.017 | -4.3 | Clumped |
Corn 1 | 0.88 | 0.014 | -8.69 | Clumped |
Rice 2 | 0.88 | 0.019 | -2.43 | Clumped |
Sugar 1 | 0.83 | 0.002 | -8.15 | Clumped |
Clump 1 | 0.8 | 0.003 | -14.79 | Clumped |
Clump 2 | 0.8 | 0.002 | -16.34 | Clumped |
Sugar 3 | 0.76 | 0.003 | -9.45 | Clumped |
Corn 2 | 0.75 | 0.039 | -11.12 | Clumped |
Sugar 4 | 0.7 | 0.011 | -6.57 | Clumped |
Waterfowl | 0.65 | 0.007 | -12.6 | Clumped |
Sugar 2 | 0.64 | 0.013 | -7.32 | Clumped |
Corn 3 | 0.47 | 0.043 | -21.97 | Clumped |