## C.d.f. of the number of heads in n coin tosses
n <- 5
x <- 0:n
y <- cumsum(choose(n,x)/2^n)
png(filename="cdf_hnt.png")
plot(x,y)
x1 <- c(-100, x)
y1 <- c(0, y)
x2 <- c(x, 100)
segments(x1,y1,x2,y1)
title(paste('C.d.f for the number of heads in n=',
             n,' trials'))
dev.off();