Creating a cumulative step graph in R

Question

Say I have this example data frame

set.seed(12345)
n1 <- 3
n2 <- 10
n3 <- 60

times <- seq(0, 100, 0.5)

individual <- c(rep(1, n1), 
                 


        

Answer 1

df$step <- 1

library(plyr)
df <- ddply(df,.(individual),transform,step=cumsum(step))

plot(step~events,data=df[df$individual==1,],type="s",xlim=c(0,max(df$events)),ylim=c(0,max(df$step)),xlab="time",ylab="step")
lines(step~events,data=df[df$individual==2,],type="s",col=2)
lines(step~events,data=df[df$individual==3,],type="s",col=3)