Trawling the online and pdf manuals for density plots further I found a reference to position and tried it with histograms. It worked!
So here is an example that gives me overlapping histograms, alpha transparency so they can both be seen in the area of overlap, and with properly labelled and colored legend. require(ggplot2) x <- data.frame(value=rnorm(5000, mean=0), case="A") y <- data.frame(value=rnorm(5000, mean=3), case="B") xy <- rbind(x, y) ggplot(xy, aes(x=value, fill=case, group=case)) + geom_histogram(alpha=0.5, binwidth=0.1, position="identity") hth -- View this message in context: http://www.nabble.com/ggplot2-legend-problem-tp25036665p25037667.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.
