使用 R while 循环生成随机变量

发布于05月17日

I want to generate a random variable X by continuing generating U(0,1) random variables as long as their product falls below exp(-2). Then my random variable X would be equal to the number of U(0,1) random variables that was generated minus 1.
I tried using the while loop to do it but not sure why the code does not return anything in my console. Please help me point out what I did wrong?

p <- 1
counter <- 0

while(p < exp(-2)) {
  u <- runif(1)
  p <- p*u
  counter <- counter+1

  X <- counter - 1
  print(X)
}

update

如果要将该过程复制100次，可以使用replicate

replicate(
    100,
    {
        p <- 1
        counter <- 0
        repeat {
            p <- p * runif(1)
            counter <- counter + 1
            if (p < exp(-2)) {
                break
            }
        }
        counter
    }
)

我想你可以用repeat和条件p < exp(-2)

p <- 1
counter <- 0
repeat {
    print(counter)
    p <- p * runif(1)
    counter <- counter + 1
    if (p < exp(-2)) {
        print(counter)
        break
    }
}