仿射空间和仿射变换=》2.1

https://www.cnblogs.com/maplewizard/p/4047001.html

http://www.fuzihao.org/blog/2014/10/23/%E4%BB%BF%E5%B0%84%E7%A9%BA%E9%97%B4%E4%B8%8E%E4%BB%BF%E5%B0%84%E5%8F%98%E6%8D%A2/