Book Image

Advanced Machine Learning with R

By : Cory Lesmeister, Dr. Sunil Kumar Chinnamgari
Book Image

Advanced Machine Learning with R

By: Cory Lesmeister, Dr. Sunil Kumar Chinnamgari

Overview of this book

R is one of the most popular languages when it comes to exploring the mathematical side of machine learning and easily performing computational statistics. This Learning Path shows you how to leverage the R ecosystem to build efficient machine learning applications that carry out intelligent tasks within your organization. You’ll work through realistic projects such as building powerful machine learning models with ensembles to predict employee attrition. Next, you’ll explore different clustering techniques to segment customers using wholesale data and even apply TensorFlow and Keras-R for performing advanced computations. Each chapter will help you implement advanced machine learning algorithms using real-world examples. You’ll also be introduced to reinforcement learning along with its use cases and models. Finally, this Learning Path will provide you with a glimpse into how some of these black box models can be diagnosed and understood. By the end of this Learning Path, you’ll be equipped with the skills you need to deploy machine learning techniques in your own projects.
Table of Contents (30 chapters)
Title Page
Copyright and Credits
About Packt
Contributors
Preface
Index

The credit card fraud dataset


Generally in a fraud dataset, we have sufficient data for the negative class (non-fraud/genuine transactions) and very few or no data for the positive class (fraudulent transactions). This is termedclass imbalance problem in the ML world. We train an AE on the non-fraud data and learn features using the encoder. The decoder is then used to compute the reconstruction error on the training set to find a threshold. This threshold will be used on the unseen data (test dataset or otherwise). We use the threshold to identify those test instances whose values are greater than the threshold as fraud instances.

For the project in this chapter, we will be using a dataset that is sourced from this URL: https://essentials.togaware.com/data/. This is a public dataset of credit card transactions. This dataset is originally made available through the research paper Calibrating Probability with Undersampling for Unbalanced Classification, A. Dal Pozzolo, O. Caelen, R. A Johnson...