Book Image

R Statistics Cookbook

By : Francisco Juretig
2 (2)
Book Image

R Statistics Cookbook

2 (2)
By: Francisco Juretig

Overview of this book

R is a popular programming language for developing statistical software. This book will be a useful guide to solving common and not-so-common challenges in statistics. With this book, you'll be equipped to confidently perform essential statistical procedures across your organization with the help of cutting-edge statistical tools. You'll start by implementing data modeling, data analysis, and machine learning to solve real-world problems. You'll then understand how to work with nonparametric methods, mixed effects models, and hidden Markov models. This book contains recipes that will guide you in performing univariate and multivariate hypothesis tests, several regression techniques, and using robust techniques to minimize the impact of outliers in data.You'll also learn how to use the caret package for performing machine learning in R. Furthermore, this book will help you understand how to interpret charts and plots to get insights for better decision making. By the end of this book, you will be able to apply your skills to statistical computations using R 3.5. You will also become well-versed with a wide array of statistical techniques in R that are extensively used in the data science industry.
Table of Contents (12 chapters)

Preprocessing

The caret package allows us to do a variety of things for preprocessing our data, such as scaling, centering, removing variables with very low variability, and projecting it via principal components. The main workhorse for this is the preProcess() function.

In this recipe, we will explore how to undertake several data transformation steps, before modeling using the Boston dataset (included in the MASS package). This is a famous dataset containing house price indexes for several areas in Boston. The objective is to use several metrics for each area and predict the price index there. We will explain how to do it using random forests.

There are essentially two ways of doing this in caret:

  • By calling the preProcess= argument in the train function (this is less flexible, but can be used with cross-validation)
  • By calling the preProcess() function before calling train...