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Turtle animation of the "8"
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<iframe 
    src="http://jsxgraph.org/share/iframe/turtle-animation-of-the-8" 
    style="border: 1px solid black; overflow: hidden; width: 550px; aspect-ratio: 55 / 65;" 
    name="JSXGraph example: Turtle animation of the "8"" 
    allowfullscreen
></iframe>
This code has to 
<div id="board-0-wrapper" class="jxgbox-wrapper " style="width: 100%; ">
   <div id="board-0" class="jxgbox" style="aspect-ratio: 1 / 1; width: 100%;" data-ar="1 / 1"></div>
</div>

<script type = "text/javascript"> 
    /*
    This example is licensed under a 
    Creative Commons Attribution ShareAlike 4.0 International License.
    https://creativecommons.org/licenses/by-sa/4.0/
    
    Please note you have to mention 
    The Center of Mobile Learning with Digital Technology
    in the credits.
    */
    
    const BOARDID = 'board-0';

    var board = JXG.JSXGraph.initBoard(BOARDID, { boundingbox: [-250, 250, 250, -250], keepaspectratio: true });
    var t = board.create('turtle', [0, 0], { strokeOpacity: 0.5 });
    t.setPenSize(3);
    t.right(90);
    var alpha = 0;
    
    var run = function() {
        t.forward(2);
        if (Math.floor(alpha / 360) % 2 === 0) {
            t.left(1); // turn left by 1 degree
        } else {
            t.right(1); // turn right by 1 degree
        }
    
        alpha += 1;
    
        if (alpha < 1440) { // stop after two rounds
            setTimeout(run, 20);
        }
    }
    
    run();
 </script> 
/*
This example is licensed under a 
Creative Commons Attribution ShareAlike 4.0 International License.
https://creativecommons.org/licenses/by-sa/4.0/

Please note you have to mention 
The Center of Mobile Learning with Digital Technology
in the credits.
*/

const BOARDID = 'your_div_id'; // Insert your id here!

var board = JXG.JSXGraph.initBoard(BOARDID, { boundingbox: [-250, 250, 250, -250], keepaspectratio: true });
var t = board.create('turtle', [0, 0], { strokeOpacity: 0.5 });
t.setPenSize(3);
t.right(90);
var alpha = 0;

var run = function() {
    t.forward(2);
    if (Math.floor(alpha / 360) % 2 === 0) {
        t.left(1); // turn left by 1 degree
    } else {
        t.right(1); // turn right by 1 degree
    }

    alpha += 1;

    if (alpha < 1440) { // stop after two rounds
        setTimeout(run, 20);
    }
}

run();
<jsxgraph width="100%" aspect-ratio="1 / 1" title="Turtle animation of the "8"" description="This construction was copied from JSXGraph examples database: BTW HERE SHOULD BE A GENERATED LINKuseGlobalJS="false">
   /*
   This example is licensed under a 
   Creative Commons Attribution ShareAlike 4.0 International License.
   https://creativecommons.org/licenses/by-sa/4.0/
   
   Please note you have to mention 
   The Center of Mobile Learning with Digital Technology
   in the credits.
   */
   
   var board = JXG.JSXGraph.initBoard(BOARDID, { boundingbox: [-250, 250, 250, -250], keepaspectratio: true });
   var t = board.create('turtle', [0, 0], { strokeOpacity: 0.5 });
   t.setPenSize(3);
   t.right(90);
   var alpha = 0;
   
   var run = function() {
       t.forward(2);
       if (Math.floor(alpha / 360) % 2 === 0) {
           t.left(1); // turn left by 1 degree
       } else {
           t.right(1); // turn right by 1 degree
       }
   
       alpha += 1;
   
       if (alpha < 1440) { // stop after two rounds
           setTimeout(run, 20);
       }
   }
   
   run();
</jsxgraph>
Use the JSXGraph turtle to draw a simple "8". 
// Define the id of your board in BOARDID

var board = JXG.JSXGraph.initBoard(BOARDID, { boundingbox: [-250, 250, 250, -250], keepaspectratio: true });
var t = board.create('turtle', [0, 0], { strokeOpacity: 0.5 });
t.setPenSize(3);
t.right(90);
var alpha = 0;

var run = function() {
    t.forward(2);
    if (Math.floor(alpha / 360) % 2 === 0) {
        t.left(1); // turn left by 1 degree
    } else {
        t.right(1); // turn right by 1 degree
    }

    alpha += 1;

    if (alpha < 1440) { // stop after two rounds
        setTimeout(run, 20);
    }
}

run();

license

This example is licensed under a Creative Commons Attribution ShareAlike 4.0 International License.
Please note you have to mention The Center of Mobile Learning with Digital Technology in the credits.