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)

Paired t-test

There is a variant of the t-test that can be used when the data is paired (this usually happens when we have two observations for each subject). For example, this may occur if we use a specific program and we want to evaluate its effectiveness by taking one measurement before and after the program is executed. The advantage of this is that the difference (after-before) truly represents the impact of the program that we are evaluating (we are making sure that any possible external variable has been filtered out).

This is much better than having just two samples, where one is taken before the policy was executed and another is one (with different individuals) taken after. If there are differences between those two samples, they might bring trouble to our test. For example, let's suppose that sample1 contains individuals that perform better at work, while sample2...