With this phase function, the neural network recognizes that we are not only learning periodic motions, but it knows when these motions start and when they end.

有这种相位，经网络就不仅仅认识到我们在学习周期性动作，还道这些动作该何时开始和结束。

For now, you learned about the qualities of rotational motion, including angular position, angular velocity, periodic motion, and the special case of rolling without slipping.

现在，您解运动的性质，包括角位置、角速度、周期运动，以及滚动不打滑的特殊情况。