Animation of lines
From JSXGraph Wiki
Click here, to start animation
The JavaScript code
The point "p0" controls the movement of the line. The coordinates of p0 define a transformation (translation). This transformation is applied to the points p1 and p2. Of course, p0 should be hidden.
var brd = JXG.JSXGraph.initBoard('jxgbox', {boundingbox: [-10, 10, 10, -10], axis: true});
var p0 = brd.create('point', [0,0], {name:'T',trace:true});
var p1 = brd.create('point', [7, 5], {name:'A',trace:true});
var p2 = brd.create('point', [5, 7], {name:'B',trace:true});
var l = brd.create('line', [p1,p2], {name:''});
var t = brd.create('transform', [function(){return p0.X();},function(){return p0.Y();}], {type:'translate'});
t.bindTo([p1,p2]); // The translation is bound to the points, but the points are not updated, yet
function startAnimation1() {
p0.moveTo([-5,-8],1500);
}
<span onClick="startAnimation1()" style="color:blue">Click here, to start animation 1</span>