Randomly Permute Time Points or Locations of "epidataCS"
epidataCS_permute.RdMonte Carlo tests for space-time interaction (epitest)
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
the events.
Usage
permute.epidataCS(x, what = c("time", "space"), keep)Arguments
- x
an object of class
"epidataCS".- what
character string determining what to permute: time points (default) or locations.
- keep
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, usekeep = time <= 30.
Value
the permuted "epidataCS" object.
Examples
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