Dumbbell plot — dumbbell

Compares a numeric value between exactly two groups across a set of categories: for each category the two group values are drawn as points joined by a connecting segment, so the size and direction of the gap is read at a glance. It is a clearer alternative to paired or grouped bars for before/after, two-condition or two-period comparisons.

Usage

dumbbell_plot(
  data,
  category,
  value,
  group,
  sort = c("gap", "value", "none"),
  point_size = 3,
  palette = NULL,
  legend_inside = FALSE,
  title = NULL,
  x_lab = NULL,
  y_lab = NULL
)

Arguments

data: A data frame.
category: The categorical axis (string or unquoted name); one row of the plot per level.
value: The numeric value to compare (string or unquoted name).
group: The two-level grouping variable whose levels are the two ends of each dumbbell (string or unquoted name).
sort: How to order the categories up the axis: "gap" (by the signed difference between the two groups, the default), "value" (by the second group's value), or "none" (the data's own order).
point_size: Size of the end points.
palette: Length-2 colours for the two groups; defaults to depictr_palette().
legend_inside: When TRUE, draw the two-group legend inside the panel (in the top-right corner, which the default gap sort with the shortest dumbbell on top usually leaves clear) over a translucent background, instead of in a right-hand margin. Defaults to FALSE.
title, x_lab, y_lab: Plot title and axis labels.

Value

A ggplot2::ggplot object.

Details

When a category has several rows per group the values are averaged. Rows with a missing category, value or group are dropped.

Examples

wb <- wellbeing_survey
wb$age_group <- ifelse(wb$age < median(wb$age), "younger", "older")
dumbbell_plot(wb, region, life_satisfaction, age_group)