Here's a cool alternative to using a for loop to build arrays - line 39

[jackcarlisle]

https://github.com/kat4/heatMap/blob/master/index.html#L39

function arr_create (n, arr_so_far) {
    if(!n) return arr_so_far;
    var arr = arr_so_far || [ ];
    return arr_create(n-1, arr.concat([0]);
}
arr_create(10);