Divide into groups and reassemble.
# S3 method for intensity
split(x, f, drop = FALSE, ..., by, unit_size)
vector or data frame containing values to be divided into groups.
a ‘factor’ in the sense that as.factor(f)
defines the grouping, or a list of such factors in which case their
interaction is used for the grouping.
logical indicating if levels that do not occur should be dropped
(if f
is a factor
or a list).
further potential arguments passed to methods.
The name(s) of the variable(s) which define(s) the grouping.
Size of a group unit. It must be a named vector, with names
corresponding to non-observational variables (i.e. space and time
variables). If the size of a variable in the data set is not a multiple
of the provided value in unit_size
, some sampling units (the last
ones) will be dropped so that clumps of individuals remain even
throughout the data set.