Hi: Try using package sos to address your question re which packages perform sine/trig regression:
library(sos) findFn('sine regression') # 12 matches on my system findFn('trigonometric regression') # 9 matches The results point largely to the mFilter, oce, circStats and circular packages. It's a place to start... HTH, Dennis On Mon, Dec 20, 2010 at 12:01 PM, Paolo Rossi < statmailingli...@googlemail.com> wrote: > Hi everyone, > > I am trying to fit a sine function on one year of wind data. I have two > questions below. > > Looking around on the net I managed to get the following: > > Sine Equation: y = a + b * sin( c + d*x ) > > b is the amplitude, c is the phase shift, d is something deal with > periodicty of data*.* > > This can be linearised by sin( c+dx ) = cos(c) * sin(dx) + sin(c) * > cos(dx). > > If one calls dx = x1 > > y = a + b * sin( c + d*x ) > y = a + b * [cos(c) * sin(x1) + sin(c) * cos(x1)] > y = a + b * cos(c) * sin(x1) + b * sin(c) * cos(x1) > y = a + b1 * sin(x1) + b2 * cos(x1) > > where b1 = b * cos(c) and b2 = b * sin(c) > > This works fine for me as I am not interested in the value for b and c. By > trial and error I also detemined that the sensibel value for d is 1/58. I > have 366 days of data and want to fit a single sine onto it. > > *First question*: 1/ 58 = (2 pi) / 366. I guess 366 is the period of my > data, I have 366 days. so *d = (2 pi) / Period*. Is this correct. > *Second question*: I reckon that all of this looks very DIY. Is there a > better way to do this in R? Maybe through a package I dont know? > > > Thanks in advance > > Paolo > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. > [[alternative HTML version deleted]] ______________________________________________ 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.