gearyc: Geary's C Autocorrelation Statistic

In DCluster: Functions for the Detection of Spatial Clusters of Diseases

Description

Geary's c statistic is used to measure autocorrelation between areas within a region, as follows:

c = (n-1) [sum_i sum_j W_ij (Z_i-Z_j)^2]/[2(sum_i sum_j W_ij) sum_k (Z_k-mean({Z))^2}

W is a squared matrix which represents the relationship between each pair of regions. An usual approach is set w_ij to 1 if regions i and j have a common boundary and 0 otherwise, or it may represent the inverse distance between the centroids of that two regions.

Small values of this statistic may indicate the presence of highly correlated areas, which may be a cluster.

References

Geary, R. C. (1954). The contiguity ratio and statistical mapping. The Incorporated Statistician 5, 115-145.

See Also

DCluster, gearyc.stat, gearyc.boot, gearyc.pboot

DCluster documentation built on May 2, 2019, 6:10 p.m.