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

Bagging


Bootstrap aggregation or bagging is the earliest ensemble technique adopted widely by the ML-practicing community. Bagging involves creating multiple different models from a single dataset. It is important to understand an important statistical technique called bootstrapping in order to get an understanding of bagging.

Bootstrapping involves multiple random subsets of a dataset being created. It is possible that the same data sample gets picked up in multiple subsets and this is termed as bootstrapping with replacement. The advantage with this approach is that the standard error in estimating a quantity that occurs due to the use of whole dataset. This technique can be better explained with an example.

Assume you have a small dataset of 1,000 samples. Based on the samples, you are asked to compute the average of the population that the sample represents. Now, a direct way of doing it is through the following formula:

As this is a small sample, we may have an error in estimating the...