On Sat, Apr 7, 2012 at 8:29 PM, wcheckle <wchec...@jhsph.edu> wrote: > Thank you David, the bwplot option does what I need: <snip> > However, I am interested in also learning how to do it in xyplot as well. I > wasn’t able to follow the last two set of instructions
That was me. Sorry for any confusion. wcheckle, these were not instructions but ramblings on an earlier code which used the original data.frame inside the lattice panel function, which in my view is an added complication in the case of only 2-3 conditioning variables. You were not meant to try and follow (the alternative was given in the form of bwplot). Your original post had two plots - in base graphics you had one conditional variable (type) and median lines, and a second was lattice with 2 variables (attend|type) without median lines. You were offered 2 solutions - David's to reproduce the first plot in lattice, and the bwplot to add medians to the second. You could work through the examples in lattice and on-line to find there is a multitude of ways to add features to grid/lattice plots. An example with panel.segments might look (untested) something like: panel=function(x,y,...) { panel.xyplot(x,y,...) yy<- tapply(y,x,median) panel.segments(x0, x1, y0= yy , y1= yy , col="red",lwd=4) } Hope that clarifies things, and again sorry everyone for any confusion that may have resulted. Best, Elai ______________________________________________ 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.