/** * jQuery.rand v1.0 
* 
* Randomly filters any number of elements from a jQuery set. 
* 
* MIT License: @link http://www.afekenholm.se/license.txt 
* 
* @author: Alexander Wallin (http://www.afekenholm.se) 
* @version: 1.0 
* @url: http://www.afekenholm.se/jquery-rand 
*/
 (function($){ 
 	$.fn.rand = function(k){ 
 		var b = this, n = b.size(),k = k ? parseInt(k) : 1;
 
		// Special cases 
		if (k > n) return b.pushStack(b); 
		else if (k == 1) return b.filter(":eq(" 
				+ Math.floor(Math.random()*n) + ")");
 
		// Create a randomized copy of the set of elements, 
		// using Fisher-Yates sorting 
		r = b.get(); 
		for (var i = 0; i < n - 1; i++) {
			var swap = Math.floor(Math.random() * (n - i)) + i; 
			r[swap] = r.splice(i, 1, r[swap])[0]; 
		}
		r = r.slice(0, k);
 
		// Finally, filter jQuery stack 
		return b.filter(function(i){
			return $.inArray(b.get(i), r) > -1;
		});
	};
})(jQuery);