Applied Data Visualization with R and ggplot2

Creating Bar Charts

Bar charts are more general than histograms, and they can represent both discrete and continuous data. They can even be used to represent categorical variables. A bar chart uses a horizontal or vertical rectangular bar that levels of at an appropriate level. A bar chart can be used to represent various quantities, such as frequency counts and percentages.

We will use the weather description data to create a bar chart. To create a bar chart, the geometric object used is geom_bar().

The syntax is as follows:

ggplot(….) + geom_bar(…)

If we use the glimpse or str command to view the weather data, we will get the following results:

You cannot use a histogram for a categorical type of variable.