A First Lesson on R and RStudio

Abstract

R is a powerful tool for statistical analyses and data visualization that is widely used and increasingly popular in criminology and criminal justice. R is open source—and it’s free! In early 2020, there were over 15,000 available packages, and the number of things that can be done with R grows exponentially every day as users keep adding new packages. Because it is open source, new statistical methods are quickly implemented, and R offers more analytical solutions, flexibility, and customizability than commonly used statistical software. This book offers a step-by-step guide for beginners to become familiar with the RStudio platform and master the fundamentals of the R programming language quickly and painlessly . The text can be used as a stand-alone guide to learning R, or it can be used as a companion guide to an introductory statistics textbook. Along the way, users will get hands-on experience with using actual criminal justice datasets, and application activity exercises are provided at the end of each chapter to practice covered material.

Key Terms

Array

A three-dimensional data structure that can contain homogenous elements (of the same class).

Assignment operators

Symbols used to make assignations to objects.

Atomic vector

A one-dimensional data structure that can contain homogenous elements (of the same class).

Comments

Code annotations that are not interpreted by R.

Data frame

A data structure that is defined by the number of rows and columns.

Environment

Where objects are stored.

List

A one-dimensional data structure that can contain heterogenous elements (of different classes).

Logical operators

Boolean operators that return TRUE or FALSE.

Matrix

A specific type of array that has at least two columns and two rows and can contain homogenous elements (of the same class).

Object

A specialized data structure; everything in R is an object.

Packages

Modules that expand what R can do.

R

A language and free software environment used for statistical computing.

R Script

Where R programming code is written and stored.

Reproducibility

When there is a record of one’s research such that these steps can be repeated by others and the findings reproduced.

RStudio

An integrated development environment (IDE) designed specifically for R.