Sine and cosine

Animation of the sine and cosine curve. Click here to start and stop animation.

The underlying JavaScript code

var board = JXG.JSXGraph.initBoard('box', {boundingbox: [-1.33, 1.33, 1.33, -1.33], axis: true});
board.suspendUpdate();
var b1c1 = board.create('circle', [[0,0], [1,0]]);
var b1p1 = board.create('point', [2, 0], {slideObject: b1c1});
var perp = board.create('perpendicular', [board.defaultAxes.x,b1p1],[{strokeColor: '#ff0000', visible: true}, {visible: false}]);
var perp2 = board.create('perpendicular',[board.defaultAxes.y,b1p1],[{strokeColor: '#0000ff', visible: true}, {visible: false}]);
board.unsuspendUpdate();

// Animation
var animated = false;
function animate(point, direction, count) {
    if(animated) {
        point.stopAnimation();
        animated = false;
    } else {
        point.startAnimation(direction, count);
        animated = true;
    }
}

var board2 = JXG.JSXGraph.initBoard('box2', {boundingbox: [-1, 1.33, 7, -1.33]});
board2.suspendUpdate();
var xax2 = board2.create('axis', [[0,0], [1,0]]);
board2.create('axis', [[0,0], [0,1]]);
board2.create('ticks', [xax2, [Math.PI, 2*Math.PI]], {strokeColor: 'green', strokeWidth: 2});

// sine:
var b2p1 = board2.create('point', [
             function(){ return JXG.Math.Geometry.rad([1,0],[0,0],b1p1); }, 
             function() { return b1p1.Y() }], 
             {fixed: true, trace: true, color: '#ff0000', name: 'S'});
// cosine:
var b2p2 = board2.create('point', [
             function(){ return JXG.Math.Geometry.rad([1,0],[0,0],b1p1); }, 
             function() { return b1p1.X() }], 
             {fixed: true, trace: true, color: '#0000ff', name: 'C'});
// Dependencies (only necessary if b2p1 or b2p2 is deleted)
b1p1.addChild(b2p1);
b1p1.addChild(b2p2);
board2.unsuspendUpdate();

board.addChild(board2);