Patty Haaem via R-help <r-help <at> r-project.org> writes:
> Dear all,I have studied “Mixed models in R using the lme4 package > Part 6: Nonlinear mixed models” by Douglas Bates. In this tutorial, > there are some codes to fit nonlinear mixed models for Theoph > data. The codes are as [follows:] Th. start <- c(lKe = -2.5, lKa = 0.5 , lCl = -3) nm1 <- nlmer ( conc ~ SSfol(Dose , Time ,lKe , lKa , lCl) ~ 0+ lKe+lKa+lCl +(0+ lKe| Subject )+(0+ lKa| Subject )+ (0+ lCl| Subject ), nAGQ =0, Theoph , start = Th.start , verbose = TRUE ) > I want to add a covariate (like age) to CL parameter. How should I > modify above codes? what's more, how are selected initial > values (lKe = -2.5, lKa = 0.5 , lCl = -3) ? Thanks in advanceElham You'll do better asking this question on r-sig-mixed-mod...@r-project.org The short answer (to the first question) is that it's not easy, but it can be done, see e.g. http://stackoverflow.com/questions/15141952/nlmer-longitudinal-data http://rpubs.com/bbolker/3423 Ben Bolker ______________________________________________ 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.