smerc (version 1.8.3)

fast.zones: Determine sequence of fast subset scan zones

Description

fast.zones determines the unique zones obtained by implementing the fast subset scan method of Neill (2012).

Usage

fast.zones(cases, pop, ubpop = 0.5, simple = TRUE)

Value

Returns a vector of regions to sequentially and cumulatively consider for clustering.

Arguments

cases

The number of cases observed in each region.

pop

The population size associated with each region.

ubpop

The upperbound of the proportion of the total population to consider for a cluster.

simple

A logical value indicating whether a simple version of the fast zones should be returned. See Details.

Author

Joshua French

Details

The simple argument determines the formatting of the returned zones. If simple = TRUE, then a vector containing the sequential indices of the regions in each successive zones is returned. If simple = FALSE, then the complete list of all zones is returned (which is the standard format of most of the other *.zones functions.

The zones returned must have a total population less than ubpop * sum(pop) of all regions in the study area.

References

Neill, D. B. (2012), Fast subset scan for spatial pattern detection. Journal of the Royal Statistical Society: Series B (Statistical Methodology), 74: 337-360. <doi:10.1111/j.1467-9868.2011.01014.x>

Examples

data(nydf)
cases <- nydf$cases
pop <- nydf$pop
# compare output format
fast.zones(cases, pop, ubpop = 0.05)
fast.zones(cases, pop, ubpop = 0.05, simple = FALSE)