Chris, I've learned those things by using R and trying to solve the problems I encounter. The dummy is nothing more than a more elegant way of using factor(1). The only connection with ggplot2, is that the plots will use the name in the dataframe or the expression. And 'dummy' looks nicer than 'factor(1)'. I've found the position = "identity" solution by looking at the error message which pointed to position = "dodge". In this case using an alternative for the position argument solved the problem.
I'm using the same resource as you do: mainly my onw experience, the online manual and the book. In case I get really stuck I use the mailing list. I haven't used gplot. Getting to know ggplot2 takes some time when you want to do some fancy stuff. But once you get the hang of it ggplot2 gives nice graphs without a very complex code. 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: donderdag 28 februari 2008 13:51 Aan: r-help@r-project.org Onderwerp: Re: [R] ggplot2 boxplot confusion Hey thanks Thierry! I learned two things here ... position="identity" AND x=dummy. Can I ask where you learned these things. I've read a lot of the online reference manual, "the book", other presentations of ggplot2 and don't recall seeing these, especially the x=dummy reference. Does this come from experience with the previous gplot package? Perhaps I should use that too? ONKELINX, Thierry wrote: > > Chris, > > You need to specify position = "identity" > > library(ggplot2) > series <- c('C2','C4','C8','C10','C15','C20') > series <- factor(series, levels = series) > ids <- c('ID1','ID2','ID3') > mydata <- > data.frame(SERIES=rep(series,30),ID=rep(ids,60),VALUE=rnorm(180), dummy > = factor(1)) > ggplot(mydata, aes(y = VALUE, x = dummy)) + geom_boxplot(position = > "identity") + facet_grid(SERIES ~ ID) > > Thierry > > -- View this message in context: http://www.nabble.com/ggplot2-boxplot-confusion-tp15706116p15735720.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.
