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geom_bar¤

There are two types of bar charts: geom_bar() and geom_col(). geom_bar() makes the height of the bar proportional to the number of cases in each group (or if the weight aesthetic is supplied, the sum of the weights). If you want the heights of the bars to represent values in the data, use geom_col() instead. geom_bar() uses stat_count() by default: it counts the number of cases at each x position. geom_col() uses stat_identity(): it leaves the data as is.

Arguments¤

  • plot::GGPlot (optional): a plot object to add this geom to. This is typically used to facilitate creating your ggplot as part of a @chain.
  • data (DataFrame): Data to use for this geom. If not provided, the geom will inherit the data from ggplot.
  • aes(...): the names of the columns in the DataFrame that will be used in the mapping
  • inherit_aes: should the geom inherit aes from the ggplot?
  • ...: options that are not mapped to a column (passed to Makie.BarPlot)

Stacking and Dodging¤

By default, multiple bars at the same position are stacked on top of each other. You can change this behavior with the position argument. Use position="dodge" to place bars side-by-side. When using position="dodge", bars will be grouped by the fill, color, group, or dodge aesthetic (checked in that order).

Required Aesthetics¤

  • x OR y (not both) - the categorical variable to count

Optional Aesthetics (see aes)¤

  • fill (maps to bar interior color)
  • color / colour (maps to bar outline color)
  • dodge (grouping variable for side-by-side bars)
  • group (grouping variable)

Optional Arguments¤

  • position: "stack" (default) or "dodge"
  • color / colour
  • stroke / strokewidth
  • strokecolor / strokecolour
  • direction: :y (default) or :x
  • dodge_gap: gap between dodged bars
  • gap: gap between bar groups
  • alpha
using TidierPlots
using DataFrames

penguins = penguins_data();

For basic counting, provide only an x aesthetic. The height of each bar will represent the count of observations in each category.

ggplot(penguins, @aes(x = species)) +
    geom_bar()

You can create a horizontal bar chart by specifying y instead of x:

ggplot(penguins, @aes(y = species)) +
    geom_bar()

Use the fill aesthetic to create stacked bar charts that show the breakdown of a second categorical variable:

ggplot(penguins, @aes(x = species, fill = sex)) +
    geom_bar()

Use position="dodge" to place bars side-by-side for easier comparison between groups:

ggplot(penguins, @aes(x = species, fill = sex)) +
    geom_bar(position = "dodge")

The dodge aesthetic can also be used directly:

ggplot(penguins, @aes(x = species, fill = sex, dodge = sex)) +
    geom_bar()

Customize the appearance with color and stroke options:

ggplot(penguins, @aes(x = species, fill = sex)) +
    geom_bar(strokecolor = :black, strokewidth = 1, alpha = 0.8)

Use the gap argument to adjust spacing between bar groups:

ggplot(penguins, @aes(x = species)) +
    geom_bar(gap = 0.5)

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