Dear Chris, You'll need to add information on the facet factor (color) to the medians dataset.
library(ggplot2) medians <- aggregate(diamonds$price, list(cut = diamonds$cut, color = diamonds$color), median) ggplot(data=diamonds, aes(x=price)) + geom_density(aes(color=cut)) + geom_vline(data=medians, aes(color=cut, intercept = x)) + facet_grid(color~.) HTH, Thierry ------------------------------------------------------------------------ ---- ir. Thierry Onkelinx Instituut voor natuur- en bosonderzoek / Research Institute for Nature and Forest Cel biometrie, methodologie en kwaliteitszorg / Section biometrics, methodology and quality assurance Gaverstraat 4 9500 Geraardsbergen Belgium tel. + 32 54/436 185 [EMAIL PROTECTED] www.inbo.be Do not put your faith in what statistics say until you have carefully considered what they do not say. ~William W. Watt A statistical analysis, properly conducted, is a delicate dissection of uncertainties, a surgery of suppositions. ~M.J.Moroney -----Oorspronkelijk bericht----- Van: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Namens Chris Friedl Verzonden: dinsdag 4 maart 2008 13:17 Aan: r-help@r-project.org Onderwerp: [R] ggplot2 - Problem with grid plot Hi R-help I'm trying to create a grid plot in which each plot in the grid contains two density plots (colored by factor) and two vertical lines at the respective medians (also colored by the factor). Using the diamonds dataset as an example, the following commands give me price density plots by factor cut in a single, ungridded plot. p <- ggplot(data=diamonds, aes(x=price)) + geom_density(aes(color=cut)) p I can add vertical lines at the medians of each density as follows. medians <- data.frame(cut=levels(diamonds$cut), intercept=tapply(diamonds$price, list(diamonds$cut), median)) p + geom_vline(data=medians, aes(color=factor(cut))) I can create a gridded plot of price density by factors cut and color (where color is the grid reference) as follows. p + facet_grid(color~.) However I've had no luck trying to now add vertical grid lines on each density plot within each grid. Can anyone offer a suggestion on how to do this? Is this a limitation with ggplot2? I'm using ggplot2 0.5.7, R 2.6.2, Windows XP. -- View this message in context: http://www.nabble.com/ggplot2---Problem-with-grid-plot-tp15825952p158259 52.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. ______________________________________________ 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.
