Book Image

Hands-On Unsupervised Learning with Python

By : Giuseppe Bonaccorso
Book Image

Hands-On Unsupervised Learning with Python

By: Giuseppe Bonaccorso

Overview of this book

Unsupervised learning is about making use of raw, untagged data and applying learning algorithms to it to help a machine predict its outcome. With this book, you will explore the concept of unsupervised learning to cluster large sets of data and analyze them repeatedly until the desired outcome is found using Python. This book starts with the key differences between supervised, unsupervised, and semi-supervised learning. You will be introduced to the best-used libraries and frameworks from the Python ecosystem and address unsupervised learning in both the machine learning and deep learning domains. You will explore various algorithms, techniques that are used to implement unsupervised learning in real-world use cases. You will learn a variety of unsupervised learning approaches, including randomized optimization, clustering, feature selection and transformation, and information theory. You will get hands-on experience with how neural networks can be employed in unsupervised scenarios. You will also explore the steps involved in building and training a GAN in order to process images. By the end of this book, you will have learned the art of unsupervised learning for different real-world challenges.
Table of Contents (12 chapters)

Evaluation metrics

In this section, we are going to analyze some common methods that can be employed to evaluate the performances of a clustering algorithm and also to help find the optimal number of clusters.

Minimizing the inertia

One of the biggest drawbacks of K-means and similar algorithms is the explicit request for the number of clusters. Sometimes this piece of information is imposed by external constraints (for example, in the example of breast cancer, there are only two possible diagnoses), but in many cases (when an exploratory analysis is needed), the data scientist has to check different configurations and evaluate them. The simplest way to evaluate K-means performance and choose an appropriate number of clusters...