Book Image

The Unsupervised Learning Workshop

By : Aaron Jones, Christopher Kruger, Benjamin Johnston
Book Image

The Unsupervised Learning Workshop

By: Aaron Jones, Christopher Kruger, Benjamin Johnston

Overview of this book

Do you find it difficult to understand how popular companies like WhatsApp and Amazon find valuable insights from large amounts of unorganized data? The Unsupervised Learning Workshop will give you the confidence to deal with cluttered and unlabeled datasets, using unsupervised algorithms in an easy and interactive manner. The book starts by introducing the most popular clustering algorithms of unsupervised learning. You'll find out how hierarchical clustering differs from k-means, along with understanding how to apply DBSCAN to highly complex and noisy data. Moving ahead, you'll use autoencoders for efficient data encoding. As you progress, you’ll use t-SNE models to extract high-dimensional information into a lower dimension for better visualization, in addition to working with topic modeling for implementing natural language processing (NLP). In later chapters, you’ll find key relationships between customers and businesses using Market Basket Analysis, before going on to use Hotspot Analysis for estimating the population density of an area. By the end of this book, you’ll be equipped with the skills you need to apply unsupervised algorithms on cluttered datasets to find useful patterns and insights.
Table of Contents (11 chapters)
Preface

Clusters as Neighborhoods

Until now, we have explored the concept of likeness being described as a function of Euclidean distance – data points that are closer to any one point can be seen as similar, while those that are further away in Euclidean space can be seen as dissimilar. This notion is seen once again in the DBSCAN algorithm. As alluded to by the lengthy name, the DBSCAN approach expands upon basic distance metric evaluation by also incorporating the notion of density. If there are clumps of data points that all exist in the same area as one another, they can be seen as members of the same cluster:

Figure 3.1: Neighbors have a direct connection to clusters

Figure 3.1: Neighbors have a direct connection to clusters

In the preceding figure, we can see four neighborhoods. The density-based approach has a number of benefits when compared to the past approaches we've covered that focus exclusively on distance. If you were just focusing on distance as a clustering threshold, then you may find your...