rbinom; How to ensure at least one "success" is returned?

Question

Is there a way to ensure rbinom() returns at least one success?

I am running rbinom() with a really low probability:

rbinom(5015, size=2, prob= 1/5000))

Since it is a probability distribution, there is a chance all 0s are returned. Is there a way to ensure that at there is at least one success returned?

Answer 1

A simple while loop can be written to keep iterating until there is at least one success in the vector (here, defined as x):

x <- 0
while(sum(x) == 0) {
  x <- rbinom(5015, size=2, prob= 1/5000)
}

# check

table(x)
#x
#   0    1 
#5013    2 # here there were two