#' @title Generates random numbers
#' @return vector of length `nc` with r.v. realizations from Gamma(rate=1)
#' @examples randdir(matrix(c(10, 30, 60), 3), 3)
#' @param counts shape parameter
#' @param nc number of rows on output
#' @seealso randga
#' @export
randdir <- function(counts, nc) {
  svar <- zeros(nc, 1)
  for (i in 1:nc) {
    svar[i, 1] <- randga(counts[i, 1], 1)
  }
  svar <- svar / sum(svar)
  return(svar)
}