The Essential R Reference

Introduction

R is rapidly becoming the de facto standard among professionals, and is used in every conceivable discipline from science and medicine to business and engineering. R is more than just a computer program; it is a statistical programming environment and language. R is free and open source and is, therefore, available to everyone with a computer.

R is a language with its own vocabulary and grammar. To make R work for you, you communicate with the computer using the language of R and tell it what to do. You accomplish this by typing commands directly into the program. This means that you need to know some of the words of the language and how to put them together to make a “sentence” that R understands. This book aims to help with this task by providing a “dictionary” of words that R understands.

The help system built into R is extensive, but it is arranged by command name; this makes it hard to use unless you know some command names to start with. That’s where this book comes in handy; the command names (the vocabulary of R) are arranged by topic, so you can look up the kind of task that you require and find the correct R command for your needs.

I like to think of this book as a cross between a dictionary, a thesaurus, and a glossary, with a fair sprinkling of practical examples. Even though some may consider me an “R expert” at this point, I am still learning and still forgetting! I often have to refer to notes to remind me how to carry out a task in R. That is why I ...