Suzette Blanchard <[EMAIL PROTECTED]> writes: > Greetings, I would like to use a cubic spline > or smoother to model the fixed effects within > nlme. So far the only smoother I have been able > to get to run successfully in nlme is smooth(). > > I tried smooth.spline: > fixed=list(lKa~1,lCL~smooth.spline(BSA, df=3)) > the error I got was the following. > Error in model.frame(formula, rownames, variables, varnames, extras, > extranames, : invalid variable type > > Can anyone suggest a cubic spline that would work within > this context?
The fixed-knots ones (ns(), bs()) should work (and did so in at least one case a couple of years ago...). These are linear, so lme() is used rather than nlme(), unless of course you have other parts that need to be modeled nonlinearly. -- O__ ---- Peter Dalgaard Blegdamsvej 3 c/ /'_ --- Dept. of Biostatistics 2200 Cph. N (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - ([EMAIL PROTECTED]) FAX: (+45) 35327907 ______________________________________________ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
