Andrew Ng Machine learning Introduction

1. 机器学习的定义：Machine learning is programming computers to optimize a performance criterion(优化性能标准) using example data or past experience.

2. 监督学习（Supervised Learning）：The term supervised learning refers to the fact that we gave the algorithm a data set in which the "right answer" were given.

    1) 回归问题（Regression）：Predict continuous valued output

    2) 分类问题（Classification）：Discrete valued output(0 or 1)

3.非监督学习（Supervised Learning）：Clustering Algorithm（聚类算法）