[ 机器学习 - 吴恩达 ] | 1-4 Unsupervised Learning

Clustering algorithms

? E.g., Google news, Genes (基因) Classification, Organize computing clusters, Social network analysis, Market segmentation, Astronomical (天文) data analysis.

Cocktail party problem (鸡尾酒会问题)

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

Q-1: Of the following examples, which would you address using an unsupervised learning algorithm?
Answer: BC
? A: Given email labeled as spam/not spam, learn a spam filter.
? B: Given a set of news articles found on the web, group them into set of articles about the same story.
? C: Given a database of customer data, automatically discover market segments and group customers into different market segments.
? D: Given a dataset of patients diagnosed (确诊) as either having diabetes (糖尿病) or not, learn to classify new patients as having diabetes or not.