R Packages

Preface

In This Book

This book will guide you from being a user of R packages to being a creator of R packages. In Chapter 1, Introduction, you’ll learn why mastering this skill is so important, and why it’s easier than you think. Next, you’ll learn about the basic structure of a package, and the forms it can take, in Chapter 2, Package Structure. The subsequent chapters go into more detail about each component. They’re roughly organized in order of importance:

Chapter 3, R code

The most important directory is R/, where your R code lives. A package with just this directory is still a useful package. (And indeed, if you stop reading the book after this chapter, you’ll have still learned some useful new skills.)

Chapter 4, Package Metadata

The DESCRIPTION lets you describe what your package needs to work. If you’re sharing your package, you’ll also use the DESCRIPTION to describe what it does, who can use it (the license), and who to contact if things go wrong.

Chapter 5, Object Documentation

If you want other people (including “future you”!) to understand how to use the functions in your package, you’ll need to document them. I’ll show you how to use roxygen2 to document your functions. I recommend roxygen2 because it lets you write code and documentation together while continuing to produce R’s standard documentation format.

Chapter 6, Vignettes: Long-Form Documentation

Function documentation describes the nitpicky details of every function in your package. Vignettes give the ...