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)

Variable selection

A fundamental question when doing linear regression is how to choose the best subset of variables that we have already included. Every variable that is added to a model changes the standard errors of the other variables already included. Consequently, the p-values also change, and the order is relevant. This happens because in general the variables are correlated, causing the coefficients' covariance matrix to change (hence changing the standard errors). Sandwich estimators use a different formula for the standard errors. Note the Ω which is the new element here. This matrix is estimated by the sandwich package. This formula also explicits why this is called the sandwich method (the Ω gets sandwiched between two equal expressions). Sandwich estimators use a different formula for the standard errors. Note the Ω which is the new element...