r-sig-mixed-models is likely to be a better list for such queries. Cheers, Bert
Bert Gunter "The trouble with having an open mind is that people keep coming along and sticking things into it." -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip ) On Thu, Mar 22, 2018 at 5:59 AM, Sorkin, John <jsor...@som.umaryland.edu> wrote: > Windows 10 64-bit, R-Studio, R version 3.4.3 > > > Several questions relating to groupedData: > > (1) I am trying to create a groupedData object that can be used to run an > analysis that I have been able to urn using lmer. When I include the > interaction terms in the groupedData opbject I get an error message stating > that + is not meaningful for factors. How do I include factors in my model? > See code and error below. > > (2) I have read the help file for groupedData multiple times. I am unable > to understand the meaning or, or the use for the inner= and outer= > parameters in the call to groupedData. Can someone either explain the > meaning of these parameters or refer me to a source that give a clear > explanation? > > > > fit0 <- lmer(THmean~INTRVNTN+factor(TimePtID)+INTRVNTN*factor( > TimePtID)+(1|PatientID),data=smalldata) > > sdgd <- groupedData(THmean~INTRVNTN+TimePtID+INTRVNTN*TimePtID| > PatientID,data=smalldata) > Warning messages: > 1: In Ops.factor(INTRVNTN, TimePtID) : ‘+’ not meaningful for factors > 2: In Ops.factor(INTRVNTN, TimePtID) : ‘*’ not meaningful for factors > > > Thank you, > > John > > > John David Sorkin M.D., Ph.D. > Professor of Medicine > Chief, Biostatistics and Informatics > University of Maryland School of Medicine Division of Gerontology and > Geriatric Medicine > Baltimore VA Medical Center > 10 North Greene Street > GRECC (BT/18/GR) > Baltimore, MD 21201-1524 > (Phone) 410-605-7119 > (Fax) 410-605-7913 (Please call phone number above prior to faxing) > > > [[alternative HTML version deleted]] > > > ______________________________________________ > 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. > > [[alternative HTML version deleted]] ______________________________________________ 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.