smooth.fd {fda} | R Documentation |
This function is intended to apply a roughness penalized smooth to data already set up as a functional data object. For example, data may have been converted to a functional data object using function data2fd using a fairly large set of basis functions, and subsequently it was desired to smooth the functional data object that resulted.
smooth.fd(fd, lambda=0, Lfd=NULL, rebase=TRUE)
fd |
The functional data object to be smoothed. |
lambda |
A nonnegative value controlling the amount of roughness in the data. |
Lfd |
Either a nonnegative integer or a linear differential operator object. If present, the derivative or the value of applying the operator is evaluated rather than the functions themselves. |
rebase |
A logical variable that is only relevant if the basis is a polygonal basis of type "polyg". If this case, if rebase is TRUE , then the basis is changed to a cubic bspline basis before smoothing. |
See function smooth.basis for details.
A functional data object.
A discussion of roughness penalties can be found in Chapter 4 of Ramsay, J. O. and Silverman, B.W. (1997) Functional Data Analysis. More information can be found in recent texts on nonparametric regression.
data2fd, plotfit.fd, smooth.basis, project.basis