index.js
function sCurve(length, rotation) {
    var curve = new Float32Array(length),
        i,
        phase = rotation > 0 ? Math.PI / 2 : -(Math.PI / 2);

    for (i = 0; i < length; ++i) {
        curve[i] = Math.sin(Math.PI * i / length - phase) / 2 + 0.5;
    }
    return curve;
}
function sCurve(length, rotation) {
    var curve = new Float32Array(length),
        i,
        phase = rotation > 0 ? Math.PI / 2 : -(Math.PI / 2);

    for (i = 0; i < length; ++i) {
        curve[i] = Math.sin(Math.PI * i / length - phase) / 2 + 0.5;
    }
    return curve;
}
function sCurve ( length , rotation ) { var curve = new Float32Array ( length ) , i , phase = rotation > 0 ? Math . PI / 2 : - ( Math . PI / 2 ) ; for ( i = 0 ; i < length ; ++ i ) { curve [ i ] = Math . sin ( Math . PI * i / length - phase ) / 2 + 0.5 ; } return curve ; }
creating a curve to simulate an S-curve with setValueCurveAtTime.
creating a curve to simulate an S - curve with setValueCurveAtTime .