Book Image

Python Machine Learning By Example - Third Edition

By : Yuxi (Hayden) Liu
Book Image

Python Machine Learning By Example - Third Edition

By: Yuxi (Hayden) Liu

Overview of this book

Python Machine Learning By Example, Third Edition serves as a comprehensive gateway into the world of machine learning (ML). With six new chapters, on topics including movie recommendation engine development with Naïve Bayes, recognizing faces with support vector machine, predicting stock prices with artificial neural networks, categorizing images of clothing with convolutional neural networks, predicting with sequences using recurring neural networks, and leveraging reinforcement learning for making decisions, the book has been considerably updated for the latest enterprise requirements. At the same time, this book provides actionable insights on the key fundamentals of ML with Python programming. Hayden applies his expertise to demonstrate implementations of algorithms in Python, both from scratch and with libraries. Each chapter walks through an industry-adopted application. With the help of realistic examples, you will gain an understanding of the mechanics of ML techniques in areas such as exploratory data analysis, feature engineering, classification, regression, clustering, and NLP. By the end of this ML Python book, you will have gained a broad picture of the ML ecosystem and will be well-versed in the best practices of applying ML techniques to solve problems.
Table of Contents (17 chapters)
15
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16
Index

Discovering Underlying Topics in the Newsgroups Dataset with Clustering and Topic Modeling

In the previous chapter, we went through a text visualization using t-SNE. T-SNE, or any dimensionality reduction algorithm, is a type of unsupervised learning. Moving forward, in this chapter, we will be continuing our unsupervised learning journey, specifically focusing on clustering and topic modeling. We will start with how unsupervised learning learns without guidance and how it is good at discovering hidden information underneath data.

Next, we will talk about clustering as an important branch of unsupervised learning, which identifies different groups of observations from data. For instance, clustering is useful for market segmentation, where consumers of similar behaviors are grouped into one segment for marketing purposes. We will perform clustering on the 20 newsgroups text dataset and see what clusters will be produced.

Another unsupervised learning route we will take is topic...