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
logical indicating if levels that do not occur should be dropped
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