Astroid Pedal Curve Variation

var xp:Number = 0;
var yp:Number = 0;
var t:Number = 0;
var r:Number = 200;
x = stage.stageWidth / 2;
y = stage.stageHeight / 2;

graphics.lineStyle(0,0x000000);
addEventListener(Event.ENTER_FRAME, onRun);
function onRun(evt:Event):void {
	r = 200 * Math.cos(t / 10);
	xp = r * Math.pow(Math.cos(t), 3);
	yp = r * Math.pow(Math.sin(t), 3);
	if (t == 0){
	  graphics.moveTo(xp, yp);
	}else{
	  graphics.lineTo(xp, yp);
	}
	t += 0.1;
}

While browsing mathworld I decided to do a variation on this curve . The above snippet will draw something like this: