Turtle animation of the "8"
From JSXGraph Wiki
The JavaScript code
var brd = JXG.JSXGraph.initBoard('jxgbox',{boundingbox: [-250, 250, 250, -250]});
var t = brd.create('turtle',[0, 0], {strokeOpacity:0.5});
t.setPenSize(3);
t.right(90);
var alpha = 0;
var run = function() {
t.fd(2);
if (Math.floor(alpha / 360) % 2 === 0) {
t.left(1);
} else {
t.right(1);
}
alpha += 1;
if (alpha < 1440) {
setTimeout(run,25);
}
}
run();