The R language is one of the best solutions for statistical data analysis. R is ideal for tasks such as data science and machine learning. R, which was created by Ross Ihaka and Robert Gentleman at the University of Auckland in 1991, is a GNU project that is similar to the S language, which was developed in the 1970s at Bell Labs.

R is an interpreted language. Input is either executed directly in the command-line interface or collected in scripts. The R language is open source and completely free. R, which runs on Linux, Windows, and macOS, has a large and active community that is constantly creating new, customized modules.

R was developed for statistics, and it comes with fast algorithms that let users analyze large datasets. There is a free and very well-integrated development environment named RStudio, as well as an excellent help system that is available in many languages.

The R language works with a library system, which makes it easy to install extensions as prebuilt packages. It is also very easy to integrate R with other well-known software tools, for example Tableau, SQL, and MS Excel. All of the libraries are available from a worldwide repository, the Comprehensive R Archive Network (CRAN) [1]. The repository contains over 10,000 packages for R, as well as important updates and the R source code.

The R language includes a variety of functions for managing data, creating and customizing data structures and types, and other tasks. R also comes with analysis functions, descriptive statistics, mathematical set and matrix operations, and higher-order functions, such as those of the Map Reduce family. In addition, R supports object-oriented programming with classes, methods, inheritance, and polymorphism.

Installing R

You can download R from the CRAN website. The CRAN site also has installation instructions for various Linux distributions. It is a good idea to also use an IDE. In this article, I will use RStudio, which is the most popular IDE for R.

RStudio is available in two formats [2]. RStudio Desktop is a normal desktop application, and RStudio server runs as a remote web server that gives users access to RStudio via a web browser. I used RStudio Desktop for the examples in this article.

When you launch RStudio Desktop after the install, you are taken to a four-panel view (Figure 1). On the left is an editor, where you can create an R script, and a console that lets you enter queries and display the output directly. Top right, the IDE shows you the environment variables and the history of executed commands. The visualizations (plots) are output at the bottom right. This is also where you can add packages and access the extensive help feature.

Figure 1: The main window of the RStudio IDE is divided into panels.

First Commands

When you type a command at the command prompt and press Enter, RStudio immediately executes that command and displays the results. Next to the first result, the IDE outputs [1]; this stands for the first value in your result. Some commands return more than one value, and the results can fill several lines.

To get started, it is a good idea to take a look at R's data types and data structures. More advanced applications build on this knowledge; if you skip over it, you might be frustrated later. Plan some time for the learning curve. The basic data types in R are summarized in Table 1. Table 2 summarizes some R data structures.

To create an initial graph, you first need to define two vectors x and y, as shown in the first two lines of Listing 1. The c stands for concatenate, but you could also think of it as collect or combine. You then pass the variables x and y to the plot() function (last line of Listing 1), along with vectors; the col parameter defines the color of the points in the output. Figure 2 shows the results.

x <- c(1, 3, 5, 8, 12)
y <- c(1, 2, 2, 4, 6)
plot(x,y,col="red")

Figure 2: An initial, very simple chart in R. The coordinates of the data points were passed in as vectors.

Installing Packages

Each R package is hosted on CRAN, where R itself is also available. But you do not need to visit the website to download an R package. Instead, you can install packages directly at the R command line. The first thing you will want to do is fetch a library for visualizations. To do this, call the install.packages("ggplot2") command in the command prompt console. The installation requires a working C compiler.

Setting up a package does not make its features available in R yet – it just puts them on your storage medium. To use the package, you need to call it in the R session with the library("ggplot2") command. After restarting R, the library is no longer active; you might need to re-enable it. Newcomers tend to overlook this step, which often leads to time-consuming troubleshooting.