Book Image

Machine Learning with Spark - Second Edition

By : Rajdeep Dua, Manpreet Singh Ghotra
Book Image

Machine Learning with Spark - Second Edition

By: Rajdeep Dua, Manpreet Singh Ghotra

Overview of this book

This book will teach you about popular machine learning algorithms and their implementation. You will learn how various machine learning concepts are implemented in the context of Spark ML. You will start by installing Spark in a single and multinode cluster. Next you'll see how to execute Scala and Python based programs for Spark ML. Then we will take a few datasets and go deeper into clustering, classification, and regression. Toward the end, we will also cover text processing using Spark ML. Once you have learned the concepts, they can be applied to implement algorithms in either green-field implementations or to migrate existing systems to this new platform. You can migrate from Mahout or Scikit to use Spark ML. By the end of this book, you will acquire the skills to leverage Spark's features to create your own scalable machine learning applications and power a modern data-driven business.
Table of Contents (13 chapters)

Extracting the right features from your data

The field of Natural Language Processing (NLP) covers a wide range of techniques to work with text, from text processing and feature extraction through to modeling and machine learning. In this chapter, we will focus on two feature extraction techniques available within Spark MLlib and Spark ML: the term frequency-inverse document frequency (tf-idf) term weighting scheme and feature hashing.

Working through an example of tf-idf, we will also explore the ways in which processing, tokenization, and filtering during feature extraction can help reduce the dimensionality of our input data as well as improve the information content and usefulness of the features we extract.

Term weighting schemes