/**
 * Used to rotate a normalized vector around a get point.
 * @param double n Containing the rotation amount
 * @return vector Containing the rotated form
 */
rotate: function (n) {
    var
        // Normalise the vector
        v = this.normalize(),

        // Find the angle
        ca = Math.cos(n),
        sa = Math.sin(n),

        // And translate the position.
        xx = v.getX() * ca - v.getY() * sa,
        yy = v.getX() * sa + v.getY() * ca;

    return vector2(xx, yy);
},