/*
 * return random number within lower/upper range
 *   output a whole number by passing returnInteger=1
 *   Examples: $R(0, 10);     >>>  3.141592653589793
 *             $R(0, 10, 1);  >>>  7
 */
function $R(lowerLimit, upperLimit, returnInteger) {
  var step1 = Math.random() * (upperLimit - lowerLimit);
  if (returnInteger && (returnInteger === 1)) {
    return lowerLimit + parseInt(step1, 10);
  } else {
    return lowerLimit + step1;
  }
}