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

Cleaning Text Data

A key component of all successful modeling exercises is a clean dataset that has been appropriately and sufficiently preprocessed for the specific data type and analysis being performed. Text data is no exception, as it is virtually unusable in its raw form. It does not matter what algorithm is being run: if the data isn't properly prepared, the results will be at best meaningless and at worst misleading. As the saying goes, garbage in, garbage out. For topic modeling, the goal of data cleaning is to isolate the words in each document that could be relevant by removing everything that could be obstructive.

Data cleaning and preprocessing is almost always specific to the dataset, meaning that each dataset will require a unique set of cleaning and preprocessing steps selected to specifically handle the issues in it. With text data, cleaning and preprocessing steps can include language filtering, removing URLs and screen names, lemmatizing, and stop word removal...