说明：  机器学习及其matlab实现一书第十九章关于强化学习的代码，有详细的注释，供初学者借鉴，很好学习强化学习资料。
(Chapter 19 of machine learning and its matlab implementation has detailed notes on the code of reinforcement learning, which can be used for reference by beginners, and is a good way to learn reinforcement learning materials.)