helper function to quickly break up array into smaller equal size arrays

chunk-it-up.js

function chunkitup(arr, chunks) {

    var len = arr.length;
    var out = [];
    var i   = 0;

    while (i < len) {

        var chunkSize = Math.ceil((len - i) / chunks--);

        out.push(arr.slice(i, i + chunkSize));

        i += chunkSize;
    }

    return out;

},