Are you sure the factors of T are in the order you think they are? (Are you sure you are using the expected version of T.) Use print(levels(T)) to make sure.
I tried timeCats <- c("Presurgery", "Day 30", "Day 60", "Day 180", "Day 365") d <- data.frame(T = factor(rep(timeCats, 11:15), levels=timeCats), Y=seq_len(sum(11:15))) boxplot(Y ~ T, data=d) and the boxes and labels are in the order given in 'timeCats'. Bill Dunlap TIBCO Software wdunlap tibco.com On Wed, Jan 21, 2015 at 2:37 PM, Ravi Varadhan <ravi.varad...@jhu.edu> wrote: > Hi, > I have a fairly elementary problem that I am unable to figure out. I have > a continuous variable, Y, repeatedly measured at multiple times, T. The > variable T is however is coded as a factor variable having these levels: > c("Presurgery", "Day 30", "Day 60", "Day 180", "Day 365"). > When I plot the boxplot, e.g., boxplot(Y ~ T), it displays the boxes in > this order: c("Day 180", "Day 30", "Day 365", "Day 60", "Presurgery"). > Is there a way to control the order of the boxes such that they are > plotted in a particular order that I want, for example: c("Presurgery", > "Day 30", "Day 60", "Day 180", "Day 365")? > > More generally, is there a simple way to redefine the ordering of the > categorical variable such that this ordering will be used in whatever > operation is done? I looked at relevel, reorder, etc., but they did not > seem to be applicable to my problem. > > Thanks for any help. > > Best, > Ravi > > > [[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.