Random Numbers Are Too Similar To Each Other?-CodePudding

I am using this code that generates 3 random numbers that add to 72:

# https://stackoverflow.com/questions/24845909/generate-n-random-integers-that-sum-to-m-in-r
rand_vect <- function(N, M, sd = 1, pos.only = TRUE) {
    vec <- rnorm(N, M/N, sd)
    if (abs(sum(vec)) < 0.01) vec <- vec   1
    vec <- round(vec / sum(vec) * M)
    deviation <- M - sum(vec)
    for (. in seq_len(abs(deviation))) {
        vec[i] <- vec[i <- sample(N, 1)]   sign(deviation)
    }
    if (pos.only) while (any(vec < 0)) {
        negs <- vec < 0
        pos  <- vec > 0
        vec[negs][i] <- vec[negs][i <- sample(sum(negs), 1)]   1
        vec[pos][i]  <- vec[pos ][i <- sample(sum(pos ), 1)] - 1
    }
    vec
}

If I run this code 100 times:

results <- list()

for (i in 1:100)

{

r_i = rand_vect(3,72)

results[[i]] <- r_i


}

When I look at the numbers that came out:

[[1]]
[1] 23 24 25

[[2]]
[1] 25 24 23

[[3]]
[1] 24 25 23

[[4]]
[1] 23 24 25

[[5]]
[1] 25 24 23

[[6]]
[1] 24 24 24

[[7]]
[1] 24 25 23

[[8]]
[1] 24 25 23

[[9]]
[1] 24 25 23

[[10]]
[1] 24 23 25

In each iteration, all the numbers add to 72 as expected - but the numbers don't really "look that random". They all seem to be "clumped" around "24, 23, 25". I was hoping to see more "randomness" in these numbers. For example:

[[11]] [1] 5 50 17

[[12]] [1] 12 40 20

Why are the numbers in the code I am using "clumped" around 24, 23, 25 - and how can I change the above code so that there is more "randomness" in the numbers being generated?

Thank you!

CodePudding user response：

If you just want three random integers that sum to 72 you could do something like

diff(c(0, sort(sample(72, 2)), 72))