Barplots

Both histograms and boxplots are tools to visualize the distribution of numerical variables. Another commonly desired task is to visualize the distribution of a categorical variable. This is a simpler task because we’re just counting different categories within a categorical variable, also known as levels of the categorical variable. Often the best way to visualize these different counts, also known as frequencies, is with barplots (also called bar charts).

One complication, however, is how our data is represented. Is the categorical variable of interest precounted or not? For example, run the following code that manually creates two data frames representing a collection of fruit—three apples and two oranges.

We see both the fruits and fruits_counted data frames represent the same collection of fruit. Whereas fruits just lists the fruit individually, fruits_counted has a variable count that represents the precounted values of each fruit.