【ML吴恩达】3 有监督学习和无监督学习

Course 课程Machine learning with python

1 What is supervised learning ?

（1）we teach the model then with that knowledge.it can predict unkown or future instances

（2）Teaching the model with labeled data告诉模型数据和数据特征对应的标签

（3）有两种类型的监督学习-Classification and Regression

• Classification is the process of predict discrete class labels or categories • Regerssion is the process of predicting continuous values

2 What is unsupervised learning?

（1）我们不用监督模型，让模型自己去挖掘特征和标签。The model works on its own to discover information .意味着无监督学习算法训练数据，然后得到一个未标签的数据。 （2）无监督学习技术 • Dimension reduction • Density estimation发现数据结构 • Market basket analysis • Clustering

3 What is clustering?

（1）Clustering is grouping of data points or objects that are somehow similar by • Discover structure • Summarization • Anomaly detection

4 Supervised VS unsupervised learning