https://blog.csdn.net/snowdroptulip/article/details/79125912
https://www.cnblogs.com/runner-ljt/p/5245080.html
http://www.nniiem.ru/file/news/2016/stl-statistical-model.pdf
https://www.cnblogs.com/en-heng/p/9202654.html
原文：https://www.cnblogs.com/xuxm2007/p/10166041.html