ModernDive

1.1 What are R and RStudio?

Throughout this book, we will assume that you are using R via RStudio. First time users often confuse the two. At its simplest, R is like a car’s engine while RStudio is like a car’s dashboard as illustrated in Figure 1.1.

Analogy of difference between R and RStudio.

FIGURE 1.1: Analogy of difference between R and RStudio.

More precisely, R is a programming language that runs computations, while RStudio is an integrated development environment (IDE) that provides an interface by adding many convenient features and tools. So just as the way of having access to a speedometer, rearview mirrors, and a navigation system makes driving much easier, using RStudio’s interface makes using R much easier as well.

1.1.1 Installing R and RStudio

Note about RStudio Server or RStudio Cloud: If your instructor has provided you with a link and access to RStudio Server or RStudio Cloud, then you can skip this section. We do recommend after a few months of working on RStudio Server/Cloud that you return to these instructions to install this software on your own computer though.

You will first need to download and install both R and RStudio (Desktop version) on your computer. It is important that you install R first and then install RStudio.

  1. You must do this first: Download and install R by going to https://cloud.r-project.org/.
    • If you are a Windows user: Click on “Download R for Windows”, then click on “base”, then click on the Download link.
    • If you are macOS user: Click on “Download R for (Mac) OS X”, then under “Latest release:” click on R-X.X.X.pkg, where R-X.X.X is the version number. For example, the latest version of R as of November 25, 2019 was R-3.6.1.
    • If you are a Linux user: Click on “Download R for Linux” and choose your distribution for more information on installing R for your setup.
  2. You must do this second: Download and install RStudio at https://www.rstudio.com/products/rstudio/download/.
    • Scroll down to “Installers for Supported Platforms” near the bottom of the page.
    • Click on the download link corresponding to your computer’s operating system.

1.1.2 Using R via RStudio

Recall our car analogy from earlier. Much as we don’t drive a car by interacting directly with the engine but rather by interacting with elements on the car’s dashboard, we won’t be using R directly but rather we will use RStudio’s interface. After you install R and RStudio on your computer, you’ll have two new programs (also called applications) you can open. We’ll always work in RStudio and not in the R application. Figure 1.2 shows what icon you should be clicking on your computer.

Icons of R versus RStudio on your computer.

FIGURE 1.2: Icons of R versus RStudio on your computer.

After you open RStudio, you should see something similar to Figure 1.3. (Note that slight differences might exist if the RStudio interface is updated after 2019 to not be this by default.)

RStudio interface to R.

FIGURE 1.3: RStudio interface to R.

Note the three panes which are three panels dividing the screen: the console pane, the files pane, and the environment pane. Over the course of this chapter, you’ll come to learn what purpose each of these panes serves.