谈谈分类器的损失函数(1):
http://www.10tiao.com/html/149/201607/2650470558/1.html
http://www.csuldw.com/2016/03/26/2016-03-26-loss-function/
http://blog.youkuaiyun.com/google19890102/article/details/50522945
logistic回归的计算:http://www.cnblogs.com/sparkwen/p/3441197.html
softmax回归:
http://ufldl.stanford.edu/wiki/index.php/Softmax%E5%9B%9E%E5%BD%92
最大似然估计:
https://zh.wikipedia.org/wiki/%E6%9C%80%E5%A4%A7%E4%BC%BC%E7%84%B6%E4%BC%B0%E8%AE%A1
中心极限定理: