Book Image

Python Machine Learning Cookbook - Second Edition

By : Giuseppe Ciaburro, Prateek Joshi
Book Image

Python Machine Learning Cookbook - Second Edition

By: Giuseppe Ciaburro, Prateek Joshi

Overview of this book

This eagerly anticipated second edition of the popular Python Machine Learning Cookbook will enable you to adopt a fresh approach to dealing with real-world machine learning and deep learning tasks. With the help of over 100 recipes, you will learn to build powerful machine learning applications using modern libraries from the Python ecosystem. The book will also guide you on how to implement various machine learning algorithms for classification, clustering, and recommendation engines, using a recipe-based approach. With emphasis on practical solutions, dedicated sections in the book will help you to apply supervised and unsupervised learning techniques to real-world problems. Toward the concluding chapters, you will get to grips with recipes that teach you advanced techniques including reinforcement learning, deep neural networks, and automated machine learning. By the end of this book, you will be equipped with the skills you need to apply machine learning techniques and leverage the full capabilities of the Python ecosystem through real-world examples.
Table of Contents (18 chapters)

Evaluating the performance of clustering algorithms

So far, we have built different clustering algorithms, but haven't measured their performance. In supervised learning, the predicted values with the original labels are compared to calculate their accuracy. In contrast, in unsupervised learning, we have no labels, so we need to find a way to measure the performance of our algorithms.

Getting ready

A good way to measure a clustering algorithm is by seeing how well the clusters are separated. Are the clusters well separated? Are the datapoints in a cluster that is tight enough? We need a metric that can quantify this behavior. We will use a metric called the silhouette coefficient score. This score is defined for each...