Methods to extract strata information from an object.
Here we only define a method for class "sts".
Usage
stratum(x, ...)
# S4 method for sts
stratum(x, which = NULL, ...)
Value
a character vector of strata names of length ncol(x).
Arguments
x
an object of class "sts".
...
further arguments passed to methods.
which
an integer (strata dimension) or NULL (to get the plain
colnames, the default).
Methods (by class)
sts: Extract the names of the units, i.e., the colnames,
from a multivariate "sts" object.
If the units result from the interaction of multiple strata
separated by dots, e.g., "region.group",
the function can also extract the names corresponding to a specific
strata dimension, e.g., which = 2 to get the group names.