【Math】拟合优度

https://blog.csdn.net/ytdxyhz/article/details/51730995

https://blog.csdn.net/snowdroptulip/article/details/79022532

https://zhidao.baidu.com/question/2122004004119441267.html

https://zhidao.baidu.com/question/2122004004119441267.html