<div id="container"></div>
html, body, #container {
width: 100%;
height: 100%;
margin: 0;
padding: 0;
}
var stage = acgraph.create("container");
var center = new acgraph.math.Coordinate(150, 100);
var simpleEllipse = stage.ellipse();
// Sets center.
simpleEllipse.center(center);
simpleEllipse.setRadius(100, 50);