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)

Using a tf-idf model

While we often refer to training a tf-idf model, it is actually a feature extraction process or transformation rather than a machine learning model. Tf-idf weighting is often used as a preprocessing step for other models, such as dimensionality reduction, classification, or regression.

To illustrate the potential uses of tf-idf weighting, we will explore two examples. The first is using the tf-idf vectors to compute document similarity, while the second involves training a multilabel classification model with the tf-idf vectors as input features.

Document similarity with the 20 Newsgroups dataset and tf-idf features

You might recall from Chapter 5, Building a Recommendation Engine with Spark, that the similarity between two vectors can be computed...