Dear All, I have created a time trend by doing x<-1:93 because I have a time series with 93 data points. Next I did :-
y = lm(series ~ poly(x,4))$residuals to detrend series. I choose this 4 as the order of my polynomial using cross validation/ checking the absence of trend in the residuals so I think I have not overfit this series. I wish to document the formula of poly(x,4). I am not able to find it in ?poly Can someone please tell me what the formula for the orthogonal polynomial used by R is ? Thank you, Ashim [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.