Basic Plotting in ggplot2

This chapter will cover basic concepts of ggplot2 and the Grammar of Graphics, using illustrative examples. You will generate solutions to problems of increasing complexity throughout the book. Lastly, you will master advanced plotting techniques, which will enable you to add more detail and increase the quality of your graphics.

In order to use ggplot2, you will first need to install R and RStudio. R is a programming language that is widely used for advanced modeling, statistical computing, and graphic production. R is considered the base package, while RStudio is a graphical interface (or IDE) that is based on R. Visualization is a very important aspect of data analysis, and it has its own underlying grammar (similar to the English language). There are many aspects of data analysis, and visualization is one of them. So, before we go further, let's discuss visualization in more detail.

By the end of this chapter, you will be able to:

• Distinguish between different kinds of variables
• Create simple plots and geometric objects, using qplot and ggplot2
• Determine the most appropriate visualization by comparing variables
• Utilize Grammar of Graphics concepts to improve plots in ggplot2