Book Image

Apache Spark 2.x Machine Learning Cookbook

By : Mohammed Guller, Siamak Amirghodsi, Shuen Mei, Meenakshi Rajendran, Broderick Hall
Book Image

Apache Spark 2.x Machine Learning Cookbook

By: Mohammed Guller, Siamak Amirghodsi, Shuen Mei, Meenakshi Rajendran, Broderick Hall

Overview of this book

Machine learning aims to extract knowledge from data, relying on fundamental concepts in computer science, statistics, probability, and optimization. Learning about algorithms enables a wide range of applications, from everyday tasks such as product recommendations and spam filtering to cutting edge applications such as self-driving cars and personalized medicine. You will gain hands-on experience of applying these principles using Apache Spark, a resilient cluster computing system well suited for large-scale machine learning tasks. This book begins with a quick overview of setting up the necessary IDEs to facilitate the execution of code examples that will be covered in various chapters. It also highlights some key issues developers face while working with machine learning algorithms on the Spark platform. We progress by uncovering the various Spark APIs and the implementation of ML algorithms with developing classification systems, recommendation engines, text analytics, clustering, and learning systems. Toward the final chapters, we’ll focus on building high-end applications and explain various unsupervised methodologies and challenges to tackle when implementing with big data ML systems.
Table of Contents (20 chapters)
Title Page
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Principal Component Analysis (PCA) to pick the most effective latent factor for machine learning in Spark


In this recipe, we use PCA (Principal Component Analysis) to map the higher-dimension data (the apparent dimensions) to a lower-dimensional space (actual dimensions). It is hard to believe, but PCA has its root as early as 1901(see K. Pearson's writings) and again in the 1930s by H. Hotelling.

PCA attempts to pick new components in a manner that maximizes the variance along perpendicular axes and effectively transforms high-dimensional original features to a lower-dimensional space with derived components that can explain the variation (discriminate classes) in a more concise form.

The intuition beyond PCA is depicted in the following figure. Let's assume for now that our data has two dimensions (x, y) and the question we are going to ask the data is whether most of the variation (and discrimination) can be explained by only one dimension or more precisely with a linear combination of...