ang {locfit} | R Documentation |
The ang()
function is used in a locfit model formula
to specify that a variable should be treated as an angular
or periodic term. The scale
argument of
locfit()
is used to set the period.
ang(x)
x |
numeric variable to be treated periodically. |
The scale
argument to locfit
is used to specify
the period divided by 2π of the term. The default is
sacle=1
, giving a period of 2π.
Loader, C. (1999). Local Regression and Likelihood. Springer, NY (Section 6.2).
# generate an x variable, and a response with period 0.2 x <- seq(0, 1, length=200) y <- sin(10*pi*x) + rnorm(200) / 5 # compute the periodic local fit. Note the scale argument is period/(2pi) fit <- locfit(y ~ ang(x), scale=0.2/(2*pi)) # plot the fit over a single period plot(fit) # plot the fit over the full range of the data plot(fit, xlim=c(0,1))