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 - evaluating the performance of clustering models

With models such as regression, classification, and recommendation engines, there are many evaluation metrics that can be applied to clustering models to analyze their performance and the goodness of the clustering of the data points. Clustering evaluation is generally divided into either internal or external evaluation. Internal evaluation refers to the case where the same data used to train the model is used for evaluation. External evaluation refers to using data external to the training data for evaluation purposes.

Internal evaluation metrics

Common internal evaluation metrics include the WCSS we covered earlier (which is exactly the k-means objective function), the Davies-Bouldin Index, the Dunn Index...