Random points

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Draw 50 random points - version 1

In the first version each point receives random coordinates once at construction time.

board = JXG.JSXGraph.initBoard('box', {boundingbox: [-0.02, 1.02, 1.02, -0.02]});
                
function reload() {
    JXG.JSXGraph.freeBoard(board);        
    board = JXG.JSXGraph.initBoard('box', {boundingbox: [-0.02, 1.02, 1.02, -0.02]});

    board.suspendUpdate();
    for (var i=0;i<50;i++) {
        var p = board.createElement('point',
            [Math.random(),Math.random()],{size:3,withLabel:false});
    }
    board.unsuspendUpdate();
}
reload();

Draw 50 random points - version 2

Here, at construction time each point receives a function pair as coordinates. In each update these functions which return Math.random() are called. Thus in each update each point receives new random coordinates. The 50 points are updated on the onmousemove event.

Please, move the mouse pointer over this area:

board2 = JXG.JSXGraph.initBoard('box', {boundingbox: [-0.02, 1.02, 1.02, -0.02]});
board2.suspendUpdate();
for (var i=0;i<50;i++) {
    var p2 = board2.createElement('point', [function(){return Math.random();},function(){ return Math.random()}], {size:3, withLabel: false});
}
board2.unsuspendUpdate();
JXG.addEvent(document.getElementById('box2'), 'mousemove', function () { this.update(); }, board2);