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)

K-means - training a clustering model

Training for K-means in Spark ML takes an approach similar to the other models -- we pass a DataFrame that contains our training data to the fit method of the KMeans object.

Here we use the libsvm data format.

Training a clustering model on the MovieLens dataset

We will train a model for both the movie and user factors that we generated by running our recommendation model.

We need to pass in the number of clusters K and the maximum number of iterations for the algorithm to run. Model training might run for less than the maximum number of iterations if the change in the objective function from one iteration to the next is less than the tolerance level (the default for this tolerance is 0.0001).

Spark ML's k-means provides...