On Fri, Nov 14, 2008 at 1:23 PM, Stavros Macrakis <[EMAIL PROTECTED]> wrote: > Given a data frame of a categorical variable and two continuous > variables, I would like to display one continuous variable against the > other for each value of the categorical variable, all superimposed on > the same plot. For example: > > data(Indometh); str(Indometh) > Classes 'nfnGroupedData', 'nfGroupedData', 'groupedData' and > 'data.frame': 66 obs. of 3 variables: > $ Subject: Ord.factor w/ 6 levels "1"<"4"<"2"<"5"<..: 1 1 1 1 1 1 1 1 1 1 ... > $ time : num 0.25 0.5 0.75 1 1.25 2 3 4 5 6 ... > $ conc : num 1.5 0.94 0.78 0.48 0.37 0.19 0.12 0.11 0.08 0.07 ... > ... > > I can easily display conc as a function of time with one panel per > value of the categorical variable: > > xyplot ( conc ~ time | Subject , Indometh ) > > But how do I specify that I want to display all the Subjects on a > single graph, superimposing them all?
Have you tried xyplot ( conc ~ time , Indometh, groups = Subject ) ? -Deepayan > I have played with various > combinations of the formula operators ~, *, +, :, and |, but not > gotten anywhere, and I haven't been able to find a clear description > of the semantics of these operators either in the xyplot man page or > in Murrell's R Graphics > > What I'm looking for is something like the output of: > > I <- Indometh; > for (i in I$Subject) > { (if (i==1) plot else points)( > I[ I$Subject==i, c("time","conc")], > col=i, type="l"); > par(new=TRUE); } > par(new=FALSE); > > I recognize this is atrocious programming style, but I'm afraid I > don't know any better; I would appreciate guidance on how to do this > right in traditional graphics, too.... > > -s > > ______________________________________________ > 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. > ______________________________________________ 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.