nth function, execute a function every nth invocation

nth.js

/**
 * Wrap your function such that it will be executed every N times it's called.
 * This is useful in a long-running loop such as the main loop in a game, where
 * you want to execute certain functions every 10 frames, or similar, but don't
 * want to manage a dozen separate "timers".
 *
 * @param {Function} f the function to wrap
 * @param {Number} n execute the function every `n` times
 */
function nth(f, n) {
    var _i = 0;
    var _n = Math.max(n, 0);
    return function() {
        if (_i === _n) {
            _i = 0;
            return f.apply(this, arguments);
        }
        else {
            _i++;
        }
    }
}

// function ping() { return 'ping!!!' }
// 
// var ping_sample = nth( ping, 3 );
// 
// ping_sample(); // returns: undefined
// ping_sample(); // returns: undefined
// ping_sample(); // returns: ping!!!
// ping_sample(); // returns: undefined
// ping_sample(); // returns: undefined
// ping_sample(); // returns: ping!!!
// ping_sample(); // returns: undefined
// ping_sample(); // returns: undefined
// ping_sample(); // returns: ping!!!