On Wed, Apr 18, 2012 at 2:07 PM, Louis Plough <lplo...@usc.edu> wrote: > If you could lead me to an example with code, that would help me figure out > how to do it for my function
The states example in ?xyplot uses groups and subscripts in a panel function >> I read it, but I guess I don't quite understand which arguments to pass >> panel.groups to get different lm objects based on the two groups within >> Food. You are confused. panel.superpose != panel.groups. You probably wanted something like (and next time please provide data): x <- rep(1:10,2) y <- rnorm(20,rep(1:2,each=10)*x) g <- gl(2,10) xyplot(y~x,groups=g, panel=panel.superpose, panel.groups=function(x,y,...){ tmp.lm<-lm(y~x) panel.abline(tmp.lm) panel.text(2, coef(tmp.lm)%*%c(1,2), label=format(tmp.lm$coefficients[2], digits=4), pos=4) panel.xyplot(x,y,...) }) HTH >> >> On Wed, Apr 18, 2012 at 3:44 PM, Bert Gunter <gunter.ber...@gene.com>wrote: >> >>> Please read ?panel.superpose again and pay attention to the >>> panel.groups argument, where this can be specified. >>> >>> -- Bert >>> >>> On Wed, Apr 18, 2012 at 12:34 PM, Louis Plough <lplo...@usc.edu> wrote: >>> > Hi, >>> > I am trying to use xyplot to plot the relationship between size and day >>> > (y~x) by a food factor that has two levels, low and high. I have 3 reps >>> per >>> > factor/day. I want the plots from each food treatment on the same >>> axiss, >>> > so I used this code: >>> > >>> > xyplot(Size ~ Day, groups = Food, data = louis.data.means,col=1, >>> > pch=c(1,17), >>> > panel=function(x,y,groups,...){ >>> > panel.superpose(x,y,groups,...) >>> > tmp.lm<-lm(y~x) >>> > panel.abline(tmp.lm) >>> > panel.text(2, 250, label=format(tmp.lm$coefficients[2], digits=4), >>> pos=4) >>> > } >>> > ) >>> > This produces a graph of the two treatments (open circles for the low >>> food >>> > vs triangles for the high food) on the same plot, but only one >>> regression >>> > line (and slope) which seems to splits the difference between the two >>> > factors (treats them as the same data set). I would like to produce a >>> > separate regression line for the data from each of the two factors (high >>> > food vs low food). >>> > >>> > Is there a way to subset the lm by the factor "food"? >>> > >>> > Louis >>> > >>> > [[alternative HTML version deleted]] >>> > >>> > ______________________________________________ >>> > 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. >>> >>> >>> >>> -- >>> >>> Bert Gunter >>> Genentech Nonclinical Biostatistics >>> >>> Internal Contact Info: >>> Phone: 467-7374 >>> Website: >>> >>> http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm >>> >> >> > > [[alternative HTML version deleted]] > > ______________________________________________ > 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.