Installing R and RStudio

To get started with R, you lot need to acquire your own copy. This appendix will show you how to download R equally well equally RStudio, a software application that makes R easier to employ. Y'all'll get from downloading R to opening your first R session.

Both R and RStudio are gratis and piece of cake to download.

How to Download and Install R

R is maintained by an international team of developers who make the language available through the web page of The Comprehensive R Archive Network. The top of the web page provides iii links for downloading R. Follow the link that describes your operating system: Windows, Mac, or Linux.

Windows

To install R on Windows, click the "Download R for Windows" link. Then click the "base" link. Next, click the first link at the top of the new page. This link should say something like "Download R three.0.3 for Windows," except the 3.0.3 will be replaced by the almost electric current version of R. The link downloads an installer program, which installs the nearly up-to-appointment version of R for Windows. Run this program and stride through the installation wizard that appears. The wizard volition install R into your programme files folders and identify a shortcut in your Kickoff menu. Note that you'll need to accept all of the appropriate administration privileges to install new software on your machine.

Mac

To install R on a Mac, click the "Download R for Mac" link. Next, click on the R-3.0.3 package link (or the package link for the most current release of R). An installer volition download to guide you lot through the installation process, which is very like shooting fish in a barrel. The installer lets you lot customize your installation, merely the defaults will exist suitable for most users. I've never found a reason to change them. If your computer requires a password before installing new progams, you'll need it here.

Binaries Versus Source

R tin can be installed from precompiled binaries or built from source on any operating system. For Windows and Mac machines, installing R from binaries is extremely like shooting fish in a barrel. The binary comes preloaded in its own installer. Although you lot can build R from source on these platforms, the process is much more complicated and won't provide much benefit for about users. For Linux systems, the reverse is true. Precompiled binaries can exist found for some systems, but it is much more mutual to build R from source files when installing on Linux. The download pages on CRAN'southward website provide information about building R from source for the Windows, Mac, and Linux platforms.

Linux

R comes preinstalled on many Linux systems, merely you lot'll want the newest version of R if yours is out of date. The CRAN website provides files to build R from source on Debian, Redhat, SUSE, and Ubuntu systems under the link "Download R for Linux." Click the link and then follow the directory trail to the version of Linux you wish to install on. The exact installation procedure volition vary depending on the Linux system you utilize. CRAN guides the process by grouping each set of source files with documentation or README files that explain how to install on your system.

32-chip Versus 64-flake

R comes in both 32-bit and 64-bit versions. Which should yous use? In almost cases, it won't matter. Both versions apply 32-bit integers, which ways they compute numbers to the same numerical precision. The difference occurs in the style each version manages retentiveness. 64-bit R uses 64-fleck memory pointers, and 32-bit R uses 32-flake memory pointers. This means 64-bit R has a larger memory space to employ (and search through).

Equally a rule of thumb, 32-scrap builds of R are faster than 64-bit builds, though not e'er. On the other hand, 64-scrap builds tin can handle larger files and data sets with fewer retention management problems. In either version, the maximum allowable vector size tops out at around 2 billion elements. If your operating system doesn't support 64-flake programs, or your RAM is less than 4 GB, 32-fleck R is for yous. The Windows and Mac installers will automatically install both versions if your organisation supports 64-bit R.

Using R

R isn't a program that you can open and first using, similar Microsoft Give-and-take or Internet Explorer. Instead, R is a figurer language, like C, C++, or UNIX. Yous use R by writing commands in the R language and asking your computer to interpret them. In the sometime days, people ran R code in a UNIX last window—as if they were hackers in a moving-picture show from the 1980s. At present near everyone uses R with an awarding chosen RStudio, and I recommend that you lot practice, also.

R and UNIX

You can even so run R in a UNIX or BASH window by typing the command:

              R

which opens an R interpreter. Y'all tin can and so exercise your piece of work and close the interpreter by running q() when you are finished.

RStudio

RStudio is an awarding like Microsoft Word—except that instead of helping you write in English, RStudio helps you lot write in R. I use RStudio throughout the book because information technology makes using R much easier. Also, the RStudio interface looks the same for Windows, Mac OS, and Linux. That will help me match the book to your personal feel.

You tin can download RStudio for free. Simply click the "Download RStudio" button and follow the simple instructions that follow. One time you've installed RStudio, you can open information technology like whatever other program on your computer—usually by clicking an icon on your desktop.

The R GUIs

Windows and Mac users usually practice non program from a terminal window, and then the Windows and Mac downloads for R come with a elementary program that opens a terminal-similar window for yous to run R code in. This is what opens when you click the R icon on your Windows or Mac computer. These programs do a piddling more than the bones terminal window, but not much. You may hear people refer to them equally the Windows or Mac R GUIs.

When y'all open RStudio, a window appears with three panes in it, as in Effigy A.1. The largest pane is a panel window. This is where you'll run your R lawmaking and run across results. The console window is exactly what you'd see if you ran R from a UNIX panel or the Windows or Mac GUIs. Everything else y'all see is unique to RStudio. Hidden in the other panes are a text editor, a graphics window, a debugger, a file manager, and much more. You'll learn virtually these panes as they become useful throughout the course of this book.

The RStudio IDE for R.

Figure A.1: The RStudio IDE for R.

Do I still need to download R?

Fifty-fifty if you use RStudio, yous'll still need to download R to your reckoner. RStudio helps yous utilise the version of R that lives on your computer, but it doesn't come with a version of R on its own.

Opening R

Now that you take both R and RStudio on your computer, you can brainstorm using R by opening the RStudio program. Open RStudio just every bit you would whatever program, by clicking on its icon or by typing "RStudio" at the Windows Run prompt.