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)

The standard model and ANOVA

In this recipe, we will be more interested in the regression part of it, instead of the ANOVA part. In the previous ANOVA chapter, we only used random effects for the intercepts, and this is usually not the price only way that random effects are introduced. Imagine that we model the sales in terms of price for certain customers, where we have several observations for each one of them. The ordinary least squares (OLS) standard approach would be to ignore this heterogeneity and pool all the observations together.

Naturally, this would introduce a problem, because the residuals would then be correlated (observations belonging to the same individual will produce similar residuals). The correct approach would be to introduce a random effect per individual, but there is a subtle point here: we are not expecting the response to differ in terms of an intercept...