Get full state, scaled into (approximately) [0, 1].

def get_scaled_state(self):
        '''Get full state, scaled into (approximately) [0, 1].'''
        return [0.5 * (self.x + self.position_limit) / self.position_limit,
                (self.dx + 0.75) / 1.5,
                0.5 * (self.theta + self.angle_limit_radians) / self.angle_limit_radians,
                (self.dtheta + 1.0) / 2.0]