Rug plot - an laternative to show a scatter plot with densities

rugplot.r

library(ggplot2)

x<-rnorm(300)
y<-rt(300,df=2)
xy<-data.frame(x,y)

qplot(x,y, data=xy) +
  scale_x_continuous(limits=c(min(x),max(x))) +
  scale_y_continuous(limits=c(min(y),max(y))) +
  geom_rug(col=rgb(.5,0,0,alpha=.2))