Two other possibilities: The 'DierckxSpline' package includes a function 'percur' for fitting periodic splines. Unfortunately, it has a known bug that kills R with a segmentation fault, though it not affect your application. The 'fda' package supports the use of finite Fourier series for fitting periodic functions. Below please find code for this that I just posted to R-devel in response to a report of the 'percur' bug. Hope this helps. Spencer Graves

# problem
x <- seq(0.2, 0.8, 0.01)
y <- cos(2*pi*x2) + 0.1*rnorm(length(x))
plot(x, y, xlim=0:1)

# simple solution
library(fda)
Fourier1 <- create.fourier.basis()
FourierFit <- Data2fd(x, y, Fourier1)
plotfit.fd(y, x, FourierFit)

# Allow more flexibility
Fourier9 <- create.fourier.basis(nbasis=2*9+1)
# constant + 9 cosine & sine terms

# Naive initial solution
FourierSmooth0 <- smooth.basisPar(x, y, Fourier9)
plotfit.fd(y, x, FourierSmooth0$fd)
# Oops:  Need some smoothing

# Try again.
FourierSmooth1 <- smooth.basisPar(x, y, Fourier9, lambda=1)
plotfit.fd(y, x, FourierSmooth1$fd)
# Much better.

######################################
Simon Wood wrote:
The "cc" and "cp" bases in package `mgcv' provide periodic splines, [e.g. gam(y~s(x,bs="cc"))], but this may not be exactly the functionality you want.

best,
Simon

On Friday 16 January 2009 08:42, cmr.p...@gmail.com wrote:
Hello group!

Is there a package that allows to fit smooth *periodic* splines to
data? I'm interested in a function which combines the functionality of
smooth.spline and splines::periodicSpline.

Thanks,
Andrey

______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html and provide commented, minimal,
self-contained, reproducible code.



______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

Reply via email to