[Error Function] math.erf is not define (Are some functions disabled in roll20?

I can't for the life of me get the math.erf function to work (as documented to be a function available in javascript  1 )? Is it disabled/prohibited or am i doing something incorrectly?

Here's the solution: function erf(y) { // save the sign of y var sign = (y >= 0) ? 1 : -1; y = Math.abs(y); var a1 = 0.254829592; var a2 = -0.284496736; var a3 = 1.421413741; var a4 = -1.453152027; var a5 = 1.061405429; var p = 0.3275911; var t = 1.0/(1.0 + p*y); var z = 1.0 - (((((a5 * t + a4) * t) + a3) * t + a2) * t + a1) * t * Math.exp(-y * y); return sign * z; }

math.js is a library for JavaScript, not a part of the language. Glad you found a solution. 

For the actual built-in Math functions, see&nbsp;<a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math" rel="nofollow">https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math</a>