Rick DeShon <deshon <at> msu.edu> writes: .. > When I use nlsList code that is virtually identical to the example in > the doc file I get the following error. .. > "Error in nlsList.formula(RT ~ SSasymp(trial, Asym, R0, lrc), > data = df.group, : > Data must be a groupedData object if formula does not include groups" .. > The data are clearly grouped. Just to be sure.... > > str(df.group) > Classes 'nfnGroupedData', 'nfGroupedData', 'groupedData' and > 'data.frame': 15480 obs. of 5 variables: > $ id : Ord.factor w/ 43 levels "31"<"8"<"30"<..: 41 11 33 22 4 27 5
Try to make id a non-ordered factor. I never tried this, but an ordered factor is treated more like an ordinal equispaced variable. Dieter ______________________________________________ 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.
