mark_histogram: Add a histogram mark

In glyph: A Grammar of Interactive Graphics

Add a histogram mark

Description

Counts how many rows fall into each bin of a numeric x variable and draws one bar per bin. Bins are closed on the right, like graphics::hist(), and the lowest bin also includes its left edge. Mapping color stacks one bar segment per colour within each bin.

With neither bins nor binwidth, the number of bins follows Sturges' rule and the edges are rounded to tidy values, as in graphics::hist(). All facet panels share the same bins.

The counts are computed in R when the plot is compiled. Rows with a missing x are dropped first, with a warning.

Usage

mark_histogram(
  spec,
  ...,
  data = NULL,
  style = list(),
  bins = NULL,
  binwidth = NULL
)

Arguments

spec	A glyph_spec
...	Aesthetic mappings: x (required, numeric) and color. There is no y mapping; the bar heights are the counts.
data	Optional per-mark data override
style	Named list of fixed visual properties
bins	Number of equal-width bins spanning the range of x.
binwidth	Width of each bin. Bin edges are multiples of binwidth. Takes precedence over bins.

Value

Modified glyph_spec object with the histogram mark added

Examples

glyph(mtcars, x = mpg) |>
  mark_histogram(binwidth = 2.5)

glyph documentation built on Oct. 21, 2026, 5:12 p.m.