Book Image

Mastering Machine Learning with Spark 2.x

By : Michal Malohlava, Alex Tellez, Max Pumperla
Book Image

Mastering Machine Learning with Spark 2.x

By: Michal Malohlava, Alex Tellez, Max Pumperla

Overview of this book

The purpose of machine learning is to build systems that learn from data. Being able to understand trends and patterns in complex data is critical to success; it is one of the key strategies to unlock growth in the challenging contemporary marketplace today. With the meteoric rise of machine learning, developers are now keen on finding out how can they make their Spark applications smarter. This book gives you access to transform data into actionable knowledge. The book commences by defining machine learning primitives by the MLlib and H2O libraries. You will learn how to use Binary classification to detect the Higgs Boson particle in the huge amount of data produced by CERN particle collider and classify daily health activities using ensemble Methods for Multi-Class Classification. Next, you will solve a typical regression problem involving flight delay predictions and write sophisticated Spark pipelines. You will analyze Twitter data with help of the doc2vec algorithm and K-means clustering. Finally, you will build different pattern mining models using MLlib, perform complex manipulation of DataFrames using Spark and Spark SQL, and deploy your app in a Spark streaming environment.
Table of Contents (9 chapters)
3
Ensemble Methods for Multi-Class Classification

Motivation of word vectors

Similar to the work we did in the previous chapter, traditional NLP approaches rely on converting individual words--which we created via tokenization--into a format that a computer algorithm can learn (that is, predicting the movie sentiment). Doing this required us to convert a single review of N tokens into a fixed representation by creating a TF-IDF matrix. In doing so, we did two important things behind the scenes:

  1. Individual words were assigned an integer ID (for example, a hash). For example, the word friend might be assigned to 39,584, while the word bestie might be assigned to 99,928,472. Cognitively, we know that friend is very similar to bestie; however, any notion of similarity is lost by converting these tokens into integer IDs.
  2. By converting each token into an integer ID, we consequently lose the context with which the token was used. This...