I was able to get the predicted values from the splines. Thanks so much for the help.
I wrote a loop with some of the code that Bill suggested. It seems that when using predict with nlme, it is important to be specific with what one is using as newdata. This does come through in Pinheiro and Bates, I just didn't recognize it to begin with. Bert, I did try your code, but was only getting coefficients, so I may have neglected a step. ##The successful code: library(nlme) library(splines) rootCN<-read.table("spline.txt", header=3DTRUE) rootCN$plotF<-as.factor(rootCN$plot) rcn10G<-groupedData(N ~ day | plotF, data=3DrootCN) fit10 <- lme( N~ns(day, 3), data =3D rcn10G) plot(augPred(fit10)) t<- 152:305 subject<-rootCN[11:22,2] sim<-NULL for(i in 1:12){ sim<- cbind(sim, predict(fit10, data.frame(day=3Dt, plotF=3Drep(subject[i], length(t))))) } colnames(sim) <- c(subject) par(mfrow=3Dc(4,3)) for(i in 1:12){ plot(t, sim[,i], type=3D"l", main=3Dsubject[i]) } -Ranae -- View this message in context: http://r.789695.n4.nabble.com/Do-YOU-know-an-equation-for-splines-ns-tp4632440p4633037.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.