ggplot2: Adding points to a density plot

Hi:

Try this:

library(ggplot2)
movmed <- ddply(movies, .(decade), summarise, med = median(rating))
m + geom_point(data = movmed, aes(x = med), y = 0, size = 2)

HTH,
Dennis

On Wed, Mar 31, 2010 at 4:46 AM, Johannes Graumann
<johannes_graumann at web.de

wrote:

Hi,

Consider something like

library(ggplot2)
movies$decade <- round_any(movies$year, 10)
m <- qplot(rating,data=movies,colour=factor(decade),geom="density")
m

(modified from "?stat_density").

I'd like to add on the line y=0 a dot for the median of each "decade"
category (using the same colour coding as the "fill"). I'm failing
miserably
at all my

m + geom_point

based approaches and would appreciate if someone could show me the
ggplot2 way of achieving this.

Thanks, Joh

[[alternative HTML version deleted]]