Aggregate an "sts" Object Over Time or Across Units

Aggregate the matrix slots of an "sts" object. Either the time series is aggregated so a new sampling frequency of nfreq observations per year is obtained (i.e., as in aggregate.ts), or the aggregation is over all columns (units).

Usage

# S4 method for class 'sts'
aggregate(x, by = "time", nfreq = "all", ...)

Arguments

x

an object of class "sts".

by

a string being either "time" or "unit".

nfreq

new sampling frequency for by="time". If nfreq="all" then all time points are summed.

...

unused (argument of the generic).

Value

an object of class "sts".

Warning

Aggregation over units fills the upperbound slot with NAs and the map slot is left as-is, but the object cannot be plotted by unit any longer.

The populationFrac slot is aggregated just like observed. Population fractions are recomputed if and only if x is no multinomialTS and already contains population fractions. This might not be intended, especially for aggregation over time.

Examples

data("ha.sts")
dim(ha.sts)
dim(aggregate(ha.sts, by = "unit"))
dim(aggregate(ha.sts, nfreq = 13))
# \dontshow{
## population(ha.sts) are trivial fractions, aggregate() should keep them
stopifnot(population(aggregate(ha.sts)) == 1/ncol(ha.sts))
## failed in surveillance <= 1.16.2
# }