smooth(x, twiceit=T)
"rts"
or
"cts"
) but not irregular (class
"its"
). The length of each vector, column, or channel must be at least four. Missing values (
NA
,
NaN
or
Inf
) are not accepted.
TRUE
,
smooth
performs twicing. Twicing is the process of smoothing, computing the residuals from the smooth, smoothing these, and then adding the two smoothed series together. By default,
twiceit=TRUE
.
The object to be smoothed is coerced to a regular time series. The components of the smoothing process are as follows:
Running medians of length 4.
Tukey, J.W. (1977). Exploratory Data Analysis. Reading, Massachusetts: Addison-Wesley.
Velleman, P.F. and Hoaglin, D.C. (1981). Applications, Basics, and Computing of Exploratory Data Analysis. Boston: Duxbury.
McNeil, D.R. (1976). Interactive Data Analysis.
tsplot(hstart, lty=2) lines(smooth(hstart))