Generate 3 random number that sum to 1 in R

Question

I am hoping to create 3 (non-negative) quasi-random numbers that sum to one, and repeat over and over.

Basically I am trying to partition something into three rand

Answer 1

I would simply randomly select 3 numbers from uniform distribution and then divide by their sum. Code as below.

n <- 3
x <- runif(3, 0, 1)
y <- x/sum(x)
sum(y)== 1

n could be any number you like.