You may do better (faster, more knowledgeable responses) posting on the r-sig-mixed-models list.
-- 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 Tue, Dec 20, 2016 at 6:24 PM, Wong Yoke Yong <yokeyong.w...@gmail.com> wrote: > HI all, > > I am using the nlme package to learn multilevel models, and following > examples from the textbook "Discovering Statistics Using R" when it > happened. > > [Mixed Models Code][1] > > The data set is Honeymoon Period.dat, also downloadable under their > companion website. > > [Data Set - Multilevel Models][2] > > require(nlme) > require(reshape2) > satisfactionData = read.delim("Honeymoon Period.dat", header = TRUE) > > restructuredData<-melt(satisfactionData, id = c("Person", "Gender"), > measured = c("Satisfaction_Base", "Satisfaction_6_Months", > "Satisfaction_12_Months", "Satisfaction_18_Months")) > names(restructuredData)<-c("Person", "Gender", "Time", > "Life_Satisfaction") > > > #print(restructuredData) > #restructuredData.sorted<-restructuredData[order(Person),] > > intercept <-gls(Life_Satisfaction~1, data = restructuredData, method = > "ML", na.action = na.exclude) > randomIntercept <-lme(Life_Satisfaction ~1, data = restructuredData, > random = ~1|Person, method = "ML", na.action = na.exclude, control = > list(opt="optim")) > anova(intercept, randomIntercept) > > timeRI<-update(randomIntercept, .~. + Time) > timeRS<-update(timeRI, random = ~Time|Person) > ARModel<-update(timeRS, correlation = corAR1(0, form = ~Time|Person)) > > The error occured at this moment, when I am trying to update "timeRS" > model. The error is as follows: > > Error in as.character.factor(X[[i]], ...) : malformed factor > > Help would be appreciated. Thanks! > > [1]: > https://studysites.uk.sagepub.com/dsur/study/DSUR%20R%20Script%20Files/Chapter%2019%20DSUR%20Mixed%20Models.R > [2]: https://studysites.uk.sagepub.com/dsur/study/articles.htm > > > Regards, > Yoke Yong > > [[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. ______________________________________________ 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.