x <-window(sunspots, start=1750, end=1800)
plot(x, type = 'p', ylab = "",main = "Sunspot numbers")
k <- 20
lines( filter(x, rep(1/k,k)), col = "red", lwd = 3 )
请教:其中的filter参数rep(1/k,k)该怎样理解?查阅R帮助,得到如下提示:
| filter | a vector of filter coefficients in reverse time order (as for AR or MA coefficients). |
案例:
x <- 1:100filter(x, rep(1, 3))
看后仍不解,请高人解惑!感谢!