Because of the way you've constructed the plot with qplot, you need to use:
myPlot + geom_point( data=medians, aes(x=med,shape=cut, y=0), size=2.5, ) Hadley On Wed, Apr 7, 2010 at 5:11 AM, Johannes Graumann <johannes_graum...@web.de> wrote: > Hi, > > Please consider the example below. How can I manage to overlay the points > the way I want in the second case? > > Thanks, Joh > > library(ggplot2) > > # Modify data to match "real" case > myDiamonds <- diamonds > myDiamonds[["clarity"]] <- as.character(myDiamonds[["clarity"]]) > myDiamonds[myDiamonds[["clarity"]]=="I1","clarity"] <- 1 > myDiamonds[myDiamonds[["clarity"]]=="SI2","clarity"] <- 2 > myDiamonds[myDiamonds[["clarity"]]=="SI1","clarity"] <- 3 > myDiamonds[myDiamonds[["clarity"]]=="VS2","clarity"] <- 4 > myDiamonds[myDiamonds[["clarity"]]=="VS1","clarity"] <- 5 > myDiamonds[myDiamonds[["clarity"]]=="VVS2","clarity"] <- 6 > myDiamonds[myDiamonds[["clarity"]]=="VVS1","clarity"] <- 7 > myDiamonds[myDiamonds[["clarity"]]=="IF","clarity"] <- 8 > myDiamonds[["clarity"]] <- as.numeric(myDiamonds[["clarity"]]) > > # Calculate medians > medians <- ddply( > myDiamonds, > .(cut), > summarize, > med=median(clarity, na.rm=TRUE) > ) > > # Works > myPlot <- qplot( > factor(clarity), > data=myDiamonds, > fill=cut, > geom="bar", > position="dodge" > ) > > myPlot + > geom_point( > data=medians, > aes(x=med,shape=cut), > y=0, > size=2.5, > ) > > # Doesn't work - I want density rather than count > myPlot <-qplot( > factor(clarity), > y=..count../sum(..count..), > data=myDiamonds, > fill=cut, > geom="bar", > position="dodge" > ) > > myPlot + > geom_point( > data=medians, > aes(x=med,shape=cut), > y=0, > size=2.5, > ) > > ______________________________________________ > 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. > -- Assistant Professor / Dobelman Family Junior Chair Department of Statistics / Rice University http://had.co.nz/ ______________________________________________ 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.
