On Thu, 10 Jan 2008, Carson Farmer wrote: > Hello R community, > > Does anyone know of a package that will perform cycle regression > analysis? I have searched the R-help archives etc. but have come up with > nothing so far. > If I am unable to find an existing R package to do so, is there anyone > familiar with fitting sine functions to data. My problem is this: > I have a long time-series of daily SWE estimates (SWE = snow water > equivalence, or the amount of water stored in a snowpack) which follows > a sinusoidal pattern, and I need to estimate the parameters of the sine > function that best fits this data. While there may be many contributing > sine functions and/or linear trends, I am only interested in a single > sine function that most closely fits the data (trends can be removed > separately if need be). Perhaps some sort of non-linear least squares > method would be best?
Or maybe stl? ( Seasonal Decomposition of Time Series by Loess ) Try example( stl ) and see the reference in ?stl HTH, Chuck p.s. Surely, SWE is NOT sinusoidal. At least not in my local mountains. > > Any help, or suggestions to get me on the right track are greatly > appreciated. > > Carson > > ______________________________________________ > 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. > Charles C. Berry (858) 534-2098 Dept of Family/Preventive Medicine E mailto:[EMAIL PROTECTED] UC San Diego http://famprevmed.ucsd.edu/faculty/cberry/ La Jolla, San Diego 92093-0901 ______________________________________________ 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.