adolfpf wrote: > > How do I "group" my data in "dolf" the same way the data "Orthodont" are > grouped. > >> show(dolf) > distance age Subjectt Sex > 1 6.83679 22.01 F1 F > 2 6.63245 23.04 F1 F > 3 11.58730 39.26 M2 M > >
I know that many sample in that excellent book use grouped data, but the concept of "grouped data" is more confusing than helpful. I only got started using nlme/lme when I realized that everything could be done without grouped data. Too bad, many examples in Pinheiro/Bates rely on the concept (but no longer do in the cooooooooommmming lme4). So I suggest that you try to solve the problem with vanilla data frames instead of grouped ones. In most cases, it only means that you have to put the formula into the lme(..) call instead of relying on some hidden defaults. Dieter -- View this message in context: http://r.789695.n4.nabble.com/grouping-data-tp3679803p3680115.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.