How many datapoints do you have? The spline smoothers assume a default of 10 degrees of freedom (i think), so If you have less datapoints than 10 I would guess that you get this error. Same would be true if you have >10 datapoints but many replicates of CoT~incline combinations.
Either reduce the degrees of freedom of the smoother or gather more data ;-). I would not be too sure about the sense of fitting univariate gams....There should be not too much of a difference to just plotting CoT~incline and fitting some spline to it ( i might be wrong here!) HTH Jannis --- natalieh <fbs...@leeds.ac.uk> schrieb am Do, 3.6.2010: > Von: natalieh <fbs...@leeds.ac.uk> > Betreff: [R] gam error > An: r-help@r-project.org > Datum: Donnerstag, 3. Juni, 2010 11:24 Uhr > > Hi all, > > I'm trying to use a gam (mgcv package) to analyse some data > with a roughly U > shaped curve. My model is very simple with just one > explanatory variable: > > m1<-gam(CoT~s(incline)) > > However I just keep getting the error message > > "Error in smooth.construct.tp.smooth.spec(object, dk$data, > dk$knots) : > A term has fewer unique covariate combinations than > specified maximum > degrees of freedom" > > Just wondering if anyone had come across this before/ could > offer any advice > on where the problem might lie > > Many thanks, > > Natalie > > > > -- > View this message in context: > http://r.789695.n4.nabble.com/gam-error-tp2241518p2241518.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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.
