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)

Summary

In this chapter, we have discussed the properties of the probability density functions and how they can be employed to compute actual probabilities and relative likelihoods. We have seen how to create a histogram, which is the simplest method to represent the frequency of values after grouping them into predefined bins. As histograms have some important limitations (they are very discontinuous and it's difficult to find out the optimal bin size), we have introduced the concept of kernel density estimation, which is a slightly more sophisticated way to estimate a density using smooth functions.

We have analyzed the properties of the most common kernels (Gaussian, Epanechnikov, Exponential, and Uniform) and two empirical methods that can be employed to find out the best bandwidth for each dataset. Using such a technique, we have tried to solve a very simple univariate...