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)

Independent Component Analysis

When working with standard PCA (or other techniques, such as factor analysis), the components are uncorrelated, but it's not guaranteed that they are statistically independent. In other words, let's suppose that we have a dataset, X, drawn from a joint probability distribution, p(X); if there are n components, we cannot always be sure that the following equality holds:

However, there are many important tasks, based on a common model called the cocktail party. In such scenarios, we can suppose (or we know) that many different and independent sources (for example, voices and music) overlap and generate a single signal. At this point, our goal is to try to separate the sources by applying a linear transformation to each sample. Let's consider a whitened dataset, X (so all of the components have the same informative content), which we...