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

Autoencoders

Autoencoders are a specifically designed neural network architecture that aims to compress the input information into lower dimensional space in an efficient yet descriptive manner. Autoencoder networks can be decomposed into two individual sub-networks or stages: an encoding stage and a decoding stage.

The following is a simplified autoencoder model using the CIFAR-10 dataset:

Figure 5.27: Simple autoencoder network architecture

The first, or encoding, stage takes the input information and compresses it through a subsequent layer that has fewer units than the size of the input sample. The latter stage, that is, the decoding stage, then expands the compressed form of the image and aims to return the compressed data to its original form. As such, the inputs and desired outputs of the network are the same; the network takes, say, an image in the CIFAR-10 dataset and tries to return the same image. This network architecture is shown in the preceding...