I want to create the empirical cumulative distribution function for two samples and put the plots in the same plot [R]

Question

I am using this code to generate the empirical cumulative distribution function for the two samples (you can put any numerical values in them). I would like to put them in the same plot but if you run the following commands everything is overlapping really bad [see picture 1]. Is there any way to do it like this [see picture 2] (also I want the symbols to disappear and be a line like the picture 2) .

plot(ecdf(sample[,1]),pch = 1)
par(new=TRUE)        
plot(ecdf(sample[,2]),pch = 2)

picture 1: https://www.dropbox.com/s/sg1fr8jydsch4xp/vanboeren2.png?dl=0

picture 2: https://www.dropbox.com/s/erhgla34y5bxa58/vanboeren1.png?dl=0

Update : I am doing this

  df1 <- data.frame(x = sample[,1]) 
  df2 <- data.frame(x = sample[,2])   
  ggplot(df1, aes(x, colour = "g")) + stat_ecdf()
  +geom_step(data = df2) 
  scale_x_continuous(limits = c(0, 5000)) `

which is very close (in terms of shape) but still can not put them at the same plot.

Answer 1

Try this with basic plot:

df1 <- data.frame(x = runif(200,1,5)) 
df2 <- data.frame(x = runif(200,3,8))

plot(ecdf(df1[,1]),pch = 1, xlim=c(0,10), main=NULL)
par(new=TRUE)        
plot(ecdf(df2[,1]),pch = 2, xlim=c(0,10), main=NULL)

Both graphs have now the same xlim (try removing it to see both superimposed incorrectly). The main=NULL removes the title

Result: