How do I create a grouped bar chart in R with ggplot2?

Use geom_bar(position = "dodge") from the ggplot2 package. Variables needed: 2 categorical + 1 numerical.

What data types work with a grouped bar chart?

A grouped bar chart works best with categorical, numerical data. It requires 2 categorical + 1 numerical.

Comparison CategoricalNumerical

Grouped Bar Chart

ggplot2: geom_bar(position = "dodge") · Package: ggplot2 · Variables: 2 categorical + 1 numerical

WHAT IS A GROUPED BAR CHART?

A grouped bar chart (also called a clustered bar chart or side-by-side bar chart) places multiple bars next to each other within each category, allowing direct comparison of sub-groups. For example, you might compare sales by region for each product, or test scores by gender across different subjects. The chart works best with 2-4 sub-groups per category. Beyond that, the clusters become too crowded to read. In ggplot2, use geom_bar(position = "dodge") with a fill aesthetic mapped to the grouping variable.

BEST FOR

· Comparing sub-groups within categories
· Side-by-side group comparison
· 2-4 sub-groups

AVOID WHEN

· More than 4-5 sub-groups
· When total per category matters more

R + GGPLOT2 CODE EXAMPLE

ggplot2

ggplot(mtcars, aes(x = factor(cyl), fill = factor(am))) +
  geom_bar(position = "dodge") +
  labs(title = "Cylinders by Transmission", fill = "Transmission")