This section will take our graph functions to the next level as we develop our own custom graph type. The ggplot2 package does not have a way to produce radar graphs by default, so we will develop it ourselves during this section. There are packages that extend ggplot2 with radar graph capabilities (for example, ggradar), but we will show how to create it yourself from scratch. After reading this section, you'll be equipped to develop complex graphs on your own.
Radar graphs are plotted on a circular canvas and can show many variables values at the same time. They form a radar-looking shape and are useful if you want to compare different variable values among various entities. Sometimes they are used to visually get a sense of how similar or different entities are. If you're not familiar with this type of graphs, there...