R ddplyr example 1

gistfile1.r

## The code for the toy data is exactly the same
data <- data.frame(sex = c(rep(1, 1000), rep(2, 1000)),
                   treatment = rep(c(1, 2), 1000),
                   response1 = rnorm(2000, 0, 1),
                   response2 = rnorm(2000, 0, 1))
 
## reshape2 still does its thing:
library(reshape2)
melted <- melt(data, id.vars=c("sex", "treatment"))
 
## This part is new:
library(dplyr)
grouped <- group_by(melted, sex, treatment)
summarise(grouped, mean=mean(value), sd=sd(value))