ggchull example usage

R function to add convex hulls (i.e. minimum convex polygons) to scatterplot in ggplot2, with optional grouping variable

First, download the file ggchull.R from github, then you will use source(), which gives you access to the stat_chull() function

source("ggchull.R")

require(ggplot2)

example_dataframe <- data.frame(
      x=c(rnorm(50,1),rnorm(50,10), rnorm(50,10)),
      y=c(rnorm(50,1),rnorm(50,10), rnorm(50,20)),
      grouping=rep(c("A","B","C"), each=50)
      )

qplot(x, y, data = example_dataframe) + 
  stat_chull(mapping=aes(fill=grouping), alpha=0.5) + 
  theme_bw(20)