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

PCA modeling


For the modeling process, we will use the following steps:

  1. Extract the components and determine the number to retain
  2. Rotate the retained components
  3. Interpret the rotated solution
  4. Create scores from the non-rotated components
  5. Use the scores as input variables for regression analysis with MARS and evaluate the performance on the test data

There are many different ways and packages used to conduct PCA in R, including what seems to be the most commonly used prcomp() and princomp() functions in base R. However, for my money, it seems that the psych package is the most flexible with the best options.

Component extraction

To extract the components with the psych package, you will use the principal() function. The syntax will include the data and whether or not we want to rotate the components at this time:

> pca <- principal(train_scale, rotate = "none")

You can examine the components by calling the pca object that we created. However, my primary intent is to determine what should be the...