#After spending the entire day working on this question, I have decided to reach out for support:
#I am trying to overlay a densityplot from one data set over a histogram of another, if I were to plot the two individually, they would look like: # data frame construction data.frame.A <- data.frame(rnorm(12*8), c(rep("one", 4), rep("two", 4), rep("three", 4)), c("red", "orange", "yellow", "green")) names(data.frame.A) <- c("vals", "factor.1", "factor.2") data.frame.B <- data.frame(rnorm(12*15), c(rep("one", 4), rep("two", 4), rep("three", 4)), c("red", "orange", "yellow", "green")) names(data.frame.B) <- names(data.frame.A) # stand alone plots histogram(~ vals|factor.1*factor.2, data.frame.A, type = "density") densityplot(~ vals | factor.1*factor.2, data.frame.B, plot.points = F) # I found http://www.ats.ucla.edu/STAT/R/faq/overlay_trellis.htm xyplot(write~read | ses.f, hsb2, panel=function(x, y, subscripts){ panel.xyplot(x, y, pch=16) panel.lmline(x, y, lty=4) panel.xyplot(hsb2$science[subscripts], hsb2$math[subscripts], pch=3) panel.lmline(hsb2$science[subscripts], hsb2$math[subscripts]) }, as.table=T, subscripts=T) # but it seems that the overlay only works in cases where the data comes from the same data.frame and has the same subscripting. # I have attempted a variety of incarnations of: histogram(~ vals|factor.1*factor.2, data.frame.A, type = "density", panel=function(x, ...){ panel.histogram(x,...) panel.densityplot(~ vals | factor.1*factor.2, data.frame.B, plot.points = F) }) # which obviously doesn't work. # I'm not sure if the problem lies in my poor understanding of writing functions or my poor understanding of Lattice. Is it indeed possible? # Thank you for your time. # Erin ______________________________________________ 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.