R: Data Analysis and Visualization

Creating bar charts

Bar charts are the most common data visualization for categorical data. However, we can also produce bar charts for summarized numeric variables over the category of other variables. In this recipe, we will see how to produce a bar chart that summarizes numeric variables over the category of other variables.

Getting ready

To create the bar chart, we will simulate a dataset with three numeric variables and one categorical variable for the purpose of grouping. The three numeric variables will indicate the incubation period of three different diseases—say, disease A, B, and C—in weeks. The categorical variable will indicate four different age groups, for example, 1 indicates age 0-1 year, 2 indicates 1-5 years, 3 indicates 5-10 ...