Divide into groups and reassemble.

# S3 method for intensity
split(x, f, drop = FALSE, ..., by, unit_size)

## Arguments

x 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.