Answer by Shanimal for JavaScript % (modulo) gives a negative result for negative numbers

A "mod" function to return a positive result.

var mod = function (n, m) {    var remain = n % m;    return Math.floor(remain >= 0 ? remain : remain + m);};mod(5,22)   // 5mod(25,22)  // 3mod(-1,22)  // 21mod(-2,22)  // 20mod(0,22)   // 0mod(-1,22)  // 21mod(-21,22) // 1

And of course

mod(-13,64) // 51