Choose specific number with probability

Question

How can one choose a number with a specific probability p?

Say we must choose between {0, 1} and the probability p stands for

Answer 1

Take a look at sample function.

> set.seed(1)
> sample(c(0,1), size=10, replace=TRUE, prob=c(0.2,0.8))
 [1] 1 1 1 0 1 0 0 1 1 1

From the helpfile you can read:

sample takes a sample of the specified size from the elements of x using either with or without replacement.

and the argument prob in sample acts as ...

A vector of probability weights for obtaining the elements of the vector being sampled.