circle_apply
Description
This is a wrapper for zoo::rollapply() allowing to fill the resulting leading and tailing NAs by circling the vector back on itself. Apply a function to a vector and fill the ends by circling the vector so that the last values proceed the head and the first values follow the tail. Useful to smooth vectors that can be regarded as repetitive, e.g. daily climatologies.
Arguments
values – vector of values
n – size of the rolling window (passed to width argument of zoo::rollapply)
fun – function to apply (passed to FUN argument of zoo::rollapply), defaults to “mean”
Example
set.seed(200)
v <- rnorm(12, 2, 2)
r <- zoo::rollapply(v, 5, mean, fill=NA)
s <- circle_apply(v, n = 5)
plot(v)
points(r, col="blue")
points(s, col="red", pch="x")