Sample with a max

Question

If I want to sample numbers to create a vector I do:

set.seed(123)
x <- sample(1:100,200, replace = TRUE)
sum(x)
# [1] 10228

What if I

Answer 1

I thought of stars and bars and partitions in combinatorics:

foo <- function(n,total) {
  while(!exists("x",inherits=FALSE) || 1 %in% diff(x)) {
    x <- sort(c(0,sample.int(n+total,n-1,replace=FALSE),n+total))
  }
  print(x)
  sort(diff(x)-1)
}

Another method is to use the partitions package. This is more suited to enumerating all partitions, but it is okay for now. It works as long as your total number is small.

require(partitions)
foo <- function(n,total) { 
  x <- restrictedparts(total,n,include.zero=FALSE)
  return(x[,sample.int(ncol(x),1)])
}