# [ 机器学习 – 吴恩达 ] 介绍 | 1-4 非监督学习([machine learning – Wu Enda] introduction | 1-4 unsupervised learning)-其他

## [ 机器学习 – 吴恩达 ] 介绍 | 1-4 非监督学习([machine learning – Wu Enda] introduction | 1-4 unsupervised learning)

### 鸡尾酒会问题

[W,s,v] = svd((repmat(sum(x.*x,1),size(x,1),1).*x)*x’)

A: 给定标记为垃圾或非垃圾的邮件，学习一个垃圾邮件分类器
B: 给定在网上找到的一组文章，将它们分为关于同一故事的一组文章
C：给定一个客户数据库，自动发现细分市场，并将客户分为不同的市场划分。
D：给定一个诊断为患有或未患糖尿病的患者数据集，学习将新患者分为是否患有糖尿病。

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### clustering algorithm

Examples: Google News, gene classification, organization, computer clustering, social network analysis, market segmentation, astronomical data analysis

### Cocktail Party Problem

[W,s,v] = svd((repmat(sum(x.*x,1),size(x,1),1).*x)*x’)

< strong > question 1: < / strong > which of the following examples would you use unsupervised learning algorithm to solve?
< strong > answer: < / strong > BC
A: Given a message marked as spam or non spam, learn a spam classifier
B: Given a group of articles found on the Internet, divide them into a group of articles about the same story
C: Given a customer database, we can automatically find market segments and divide customers into different market segments.
D: given a dataset diagnosed with or without diabetes, we divided the new patient into diabetes.