Plot-R

 x <- rnorm(50)
> hist(x, probability = TRUE)
> lines(density(x))
> xval <- pretty(c(-3, 3), 50)
> lines(xval, dnorm(xval), col = "red")
> plot(density(rnorm(50), bw = 0.2), type = "l")
> plot(density(rnorm(50), bw = 0.6), type = "l")