tango.stat {DCluster}R Documentation

Compute Tango's statistic for general clustering

Description

Compute Tango's statistic for general clustering. See tango manual page for details.

Usage

tango.stat(data, listw, zero.policy)

Arguments

data Dataframe with the data as described in DCluster.
listw Neighbours list with spatial weights created, for example, by 'nb2listw' (package spdep).
zero.policy See nb2listw in package spdep.

References

Tango, Toshiro (1995). A Class of Tests for Detecting 'General' and 'Focused' Clustering of Rare Diseases. Statistics in Medicine 14, 2323-2334.

See Also

DCluster, tango, tango.boot, tango.pboot

Examples

library(spdep)
data(nc.sids)

sids<-data.frame(Observed=nc.sids$SID74)
sids<-cbind(sids, Expected=nc.sids$BIR74*sum(nc.sids$SID74)/sum(nc.sids$BIR74) )
sids<-cbind(sids, x=nc.sids$x, y=nc.sids$y)

#Calculate neighbours based on distance
coords<-as.matrix(sids[,c("x", "y")])

dlist<-dnearneigh(coords, 0, Inf)
dlist<-include.self(dlist)
dlist.d<-nbdists(dlist, coords)

#Calculate weights. They are globally standardised but it doesn't
#change significance.
col.W.tango<-nb2listw(dlist, glist=lapply(dlist.d, function(x) {exp(-x)}),
        style="C")

niter<-100

#use exp(-D) as closeness matrix
tango.stat(sids, col.W.tango, zero.policy=TRUE)


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