Book Image

Scala for Machine Learning, Second Edition - Second Edition

Book Image

Scala for Machine Learning, Second Edition - Second Edition

Overview of this book

The discovery of information through data clustering and classification is becoming a key differentiator for competitive organizations. Machine learning applications are everywhere, from self-driving cars, engineering design, logistics, manufacturing, and trading strategies, to detection of genetic anomalies. The book is your one stop guide that introduces you to the functional capabilities of the Scala programming language that are critical to the creation of machine learning algorithms such as dependency injection and implicits. You start by learning data preprocessing and filtering techniques. Following this, you'll move on to unsupervised learning techniques such as clustering and dimension reduction, followed by probabilistic graphical models such as Naïve Bayes, hidden Markov models and Monte Carlo inference. Further, it covers the discriminative algorithms such as linear, logistic regression with regularization, kernelization, support vector machines, neural networks, and deep learning. You’ll move on to evolutionary computing, multibandit algorithms, and reinforcement learning. Finally, the book includes a comprehensive overview of parallel computing in Scala and Akka followed by a description of Apache Spark and its ML library. With updated codes based on the latest version of Scala and comprehensive examples, this book will ensure that you have more than just a solid fundamental knowledge in machine learning with Scala.
Table of Contents (27 chapters)
Scala for Machine Learning Second Edition
Credits
About the Author
About the Reviewers
www.PacktPub.com
Customer Feedback
Preface
Index

The purpose of sampling


Sampling is the process to extract a subset of a dataset that is chosen to draw inferences about the properties of this dataset. It is not always practical to use an entire dataset for the following reasons:

  • Dataset is too large

  • Dataset is not available in a timely fashion

  • Extraction of complex features is very computationally intensive

  • A very large percentage of the training data is labeled to one of the classes which require down-sampling

  • Data is a continuous signal

The most commonly-cited benefits of sampling are reduction of computation cost and latency of execution.

Note

Independent and identical distribution

It is generally assumed that the original dataset reflects an independent and identically distributed population (i.i.d).

The challenge is to devise a procedure to generate a sample that represents accurately the original dataset so that any inference derived from the sample applies equally to the original dataset.