How to save an object in a function

On Mar 18, 2016, at 11:18 PM, Prashobh Palakkeel <palakkeel at gmail.com> wrote:

This is the code for permutations from the package "gtools"

fn_perm_list <-
 function (n, r, v = 1:n)
 {
   if (r == 1)
     matrix(v, n, 1)
   else if (n == 1)
     matrix(v, 1, r)
   else {
     X <- NULL
     for (i in 1:n) X <- rbind(X, cbind(v[i], fn_perm_list(n - 1, r - 1,
v[-i])))
     X

   }

 }

How to save X as an object(matrix) while running the function