Randomly Permute Time Points or Locations of
Monte Carlo tests for space-time interaction (
use the distribution of some test statistic under the null hypothesis
of no space-time interaction. For this purpose, the function
permute.epidataCS randomly permutes the time or space labels of
permute.epidataCS(x, what = c("time", "space"), keep)
an object of class
character string determining what to permute: time points (default) or locations.
optional logical expression to be evaluated in the context of
x$events@data, determining for which events the time and location should be kept as is. For instance, to keep some “prehistory” before time point 30 unchanged, use
keep = time <= 30.
data("imdepi") set.seed(3) permepi <- permute.epidataCS(imdepi, what = "time", keep = time <= 30) print(imdepi, n = 8) print(permepi, n = 8) ## the first 6 events are kept (as are all row.names), ## the time labels of the remaining events are shuffled ## (and events then again sorted by time), ## the marginal temporal distribution is unchanged