Lesson 1:
课程的资源：http://www.stanford.edu/class/cs229/
机器学习分类：
1. 有监督学习（supervised learning）
2. 无监督学习（unsupervised learning）
Would you please find interesting structure in this data set?
3. 增强学习( reinforcement learning )
This refers to problems where you don't do oneshot decision-making.In reinforcement learning problems, you are usually asked to make a sequence of decisions over time. The basic idea behind a reinforcement learning algorithm is this idea of what's called a reward function. What we have to think about is imagine you're trying to train a dog. So every time your dog does something good, you say, "Good dog," and you reward the dog. Every time your dog does something bad, you go, "Bad dog," right? And hopefully, over time, your dog will learn to do the right things to get more of the positive rewards, to get more of the "Good dogs" and to get fewer of the "Bad dogs.”