#' @title My sum function
#' @description a symple sum function
#' @param x is a numeric vector
#' @param y is a numeric vector
#' @author Marco Beccutim marco[dot]beccuti[at]unito[dot]it, Univ. of Turin
#' @return the sum of x and y
#'
#' @examples
#'  sum(1,1)
#'  \dontrun{
#'   sum(x,y)
#'  }
#'
#' @export
sum <-function(x,y){
  return(x+y)
}