What you will learn in this chapter:
Graphs are a powerful way to present your data and results in a concise manner. Whatever kind of data you have, there is a way to illustrate it graphically. A graph is more readily understandable than words and numbers, and producing good graphs is a vital skill. Some graphs are also useful in examining data so that you can gain some idea of patterns that may exist; this can direct you toward the correct statistical analysis.
R has powerful and flexible graphical capabilities. In general terms, R has two kinds of graphical commands: some commands generate a basic plot of some sort, and other commands are used to tweak the output and to produce a more customized finish.
You have already encountered some graphical commands in previous chapters. This chapter focuses on some of the basic graph types that you may typically need to create. In Chapter 11, you will revisit the graphical commands and add a variety of extras to lift your graphs from the merely adequate, to fully polished publication quality material.
The box-whisker plot (often abbreviated to boxplot) is a useful ...