Appendix A — Glossary

Console: The console is located in RStudio’s bottom-right pane by default. The R console is an interactive programming environment where we can enter and execute R commands. It’s the the most basic interface for interacting with R, providing immediate feedback and results from the code we enter. The R console is useful for testing small pieces of code and interactive data exploration. However, we recommend using R scripts or Quarto/ files for all but the simplest programming or data analysis tasks.

Data frame. For our purposes, data frames are just R’s term for data set or data table. Data frames are made up of columns (variables) and rows (observations). In R, all columns of a data frame must have the same length.

Functions. Coming soon.

Arguments

Arguments always live inside the parentheses of R functions and receive information the function needs to generate the result we want.
Pass

In programming lingo, we pass a value to a function argument. For example, in the function call seq(from = 2, to = 100, by = 2) we could say that we passed a value of 2 to the from argument, we passed a value of 100 to the to argument, and we passed a value of 2 to the by argument.
Return

Instead of saying, “the seq() function gives us a sequence of numbers…” we could say, “the seq() function returns a sequence of numbers…” In programming lingo, functions return one or more results.

Global environment. Coming soon.

Issue (GitHub): GitHub’s documentation says issues are “items you can create in a repository to plan, discuss and track work. Issues are simple to create and flexible to suit a variety of scenarios. You can use issues to track work, give or receive feedback, collaborate on ideas or tasks, and efficiently communicate with others.”¹

Objects. Coming soon.

R: R’s documentation says “R is a language and environment for statistical computing and graphics. It is a GNU project which is similar to the S language and environment which was developed at Bell Laboratories (formerly AT&T, now Lucent Technologies) by John Chambers and colleagues.”² R is open source, and you can download it for free from The Comprehensive R Archive Network (CRAN) at https://cran.r-project.org/.
Repository: GitHub’s documentation says “a repository contains all of your code, your files, and each file’s revision history. You can discuss and manage your work within the repository.”³ A repository can exist locally as a set of files on your computer. A repository can also exist remotely as a set of files on a sever somewhere, for example, on GitHub.
RStudio: RStudio is an integrated development environment (IDE) for R. It includes a console, syntax-highlighting editor that supports direct code execution, as well as tools for plotting, history, debugging and workspace management. RStudio is available in open source and commercial editions and runs on the desktop (Windows, Mac, and Linux) or in a browser connected to RStudio Server or RStudio Server Pro (Debian/Ubuntu, Red Hat/CentOS, and SUSE Linux).⁴