Sketchy significance / comparison brackets

Draws a hand-drawn bracket spanning xmin to xmax at height y, with short tips dropping toward the data and an optional label (e.g. a p-value or "n.s.") centred above. It is the sketch counterpart of a ggsignif bracket: useful for marking pairwise comparisons on boxplots, bars, or violins.

Usage

GeomSketchBracket

geom_sketch_bracket(
  mapping = NULL,
  data = NULL,
  stat = "identity",
  position = "identity",
  ...,
  tip_length = 0.02,
  family = NULL,
  label_vjust = -0.35,
  roughness = 0.8,
  bowing = 0.4,
  n_passes = 2L,
  seed = NULL,
  na.rm = FALSE,
  show.legend = FALSE,
  inherit.aes = FALSE
)

Format

An object of class GeomSketchBracket (inherits from Geom, ggproto, gg) of length 6.

Arguments

mapping: Aesthetic mappings created by ggplot2::aes(). Requires xmin, xmax, and y; label is optional.
data: Data with one row per bracket.
stat: Statistical transformation. Default "identity".
position: Position adjustment. Default "identity".
...: Other arguments passed on to the layer.
tip_length: Length of the downward end tips, as a fraction of panel height. Default 0.02. Use 0 for a plain bar.
family: Font family for the label. By default the first installed handwriting face is used (see ggsketch_check_fonts()); pass "" for the device default.
label_vjust: Vertical justification of the label relative to the bar (negative nudges it above). Default -0.35.
roughness: Non-negative roughness (0 = straight). Default 0.8.
bowing: Non-negative bowing multiplier. Default 0.4 (kept low so the bar stays readable).
n_passes: Number of stroke passes. Default 2.
seed: Integer seed. NULL uses getOption("ggsketch.seed", 1L).
na.rm: Remove missing values silently? Default FALSE.
show.legend: Logical; include in legend? Default FALSE.
inherit.aes: Inherit aesthetics from the plot? Default FALSE.

Value

A ggplot2 layer object.

Details

Brackets are usually one-off annotations, so supply them with their own data and inherit.aes = FALSE rather than inheriting the plot's mapping.

Other sketch-geoms: GeomSketchAbline, GeomSketchBoxplot, GeomSketchCol, GeomSketchCurve, GeomSketchEllipse, GeomSketchHex, GeomSketchLine, GeomSketchLinerange, GeomSketchPath, GeomSketchPoint, GeomSketchPolygon, GeomSketchRect, GeomSketchRibbon, GeomSketchRug, GeomSketchSegment, GeomSketchSmooth, GeomSketchSpoke, GeomSketchViolin, annotate_sketch(), geom_sketch_bin2d(), geom_sketch_contour(), geom_sketch_count(), geom_sketch_density(), geom_sketch_density2d(), geom_sketch_function(), geom_sketch_histogram(), geom_sketch_jitter(), geom_sketch_qq(), geom_sketch_quantile(), geom_sketch_text()

Examples

library(ggplot2)
brackets <- data.frame(xmin = 1, xmax = 2, y = 45, label = "p = 0.01")
ggplot(mpg, aes(drv, hwy)) +
  geom_sketch_boxplot(seed = 1L) +
  geom_sketch_bracket(
    data = brackets,
    aes(xmin = xmin, xmax = xmax, y = y, label = label),
    family = "", seed = 2L
  ) +
  theme_sketch()