Box-Muller normal distribution random number generator (Google App Script)

randnormal.gs

function randnormal(minimum, mean, maximum, stdev) 
{
  // start with two uniformly distributed random numbers
  var rn1 = Math.random();
  var rn2 = Math.random();
  
  // Box-Muller transform
  var r = Math.sqrt(-2 * Math.log(rn1));
  var theta = 2 * Math.PI * rn2;
  var x = r * Math.cos(theta); // 1st of 2 random numbers generated
  
  // transform 1st Box-Muller output to desired value space
  var n = x * stdev + mean;
  
  // if value within range, return result
  if (n >= minimum & n <= maximum)
    return n;
  
  // 1st random number wasn't in range, so try 2nd random number
  var y = r * Math.sin(theta);
  n = y * stdev + mean;
  
  // if still not in range, start over with another random pair
  if (n < minimum | n > maximum)
    return randnormal(minimum, mean, maximum, stdev); // try again
  
  // 2nd value is in range, return results
  return n;
}

For use in Google Spreadsheets in code behind scripts.