continue seasonality of time series from forecast stl decomposition

Question

The stl function in the stats package decomposes a time series into seasonal, trend, and remainder:

sstl <- stl(ts(rnorm(100), frequency=12), "period")
plot(sstl)

The seasonality is a regular pattern, how can I continue this pattern for the next 50 data points?

Answer 1

You could extract the unique values of the seasonal component and then use rep_len to create a vector of length 150 as follows

rep_len(unique(sstl$time.series[, "seasonal"]), length.out = 150)