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

In this section, we will use explicit rating data, without additional user, item metadata, or other information related to the user-item interactions. Hence, the features that we need as inputs are simply the user IDs, movie IDs, and the ratings assigned to each user and movie pair.

Extracting features from the MovieLens 100k dataset

In this example, we will use the same MovieLens dataset that we used in the previous chapter. Use the directory in which you placed the MovieLens 100k dataset as the input path in the following code.

First, let's inspect the raw ratings dataset:

object FeatureExtraction { 

def getFeatures(): Dataset[FeatureExtraction.Rating] = {
val spark = SparkSession.builder.master("local[2]...