GeomSketchArrow: Sketchy content-aware arrows

Description

Draws a hand-drawn arrow from (x, y) to (xend, yend), with an optional handwriting label at the source. It is "content-aware" in three ways:

Usage

GeomSketchArrow
geom_sketch_arrow(
  mapping = NULL,
  data = NULL,
  stat = "identity",
  position = "identity",
  ...,
  curvature = "auto",
  roughness = 1,
  bowing = 1,
  n_passes = 2L,
  seed = NULL,
  arrow_length = NULL,
  arrow_angle = 25,
  arrow_type = "open",
  arrow_head = NULL,
  ends = "last",
  family = NULL,
  label_gap = 0.012,
  na.rm = FALSE,
  show.legend = FALSE,
  inherit.aes = TRUE
)

Value

A ggplot2 layer object.

Arguments

mapping: Aesthetic mappings created by ggplot2::aes(). Requires x, y, xend, yend; label is optional.
data: Data with one row per arrow.
stat: Statistical transformation. Default "identity".
position: Position adjustment. Default "identity".
...: Other arguments passed on to the layer.
curvature: Shaft bend. "auto" (default) picks a gentle bow; a number sets it explicitly (0 straight, positive/negative bow to either side).
roughness: Non-negative roughness (0 = clean). Default 1.
bowing: Non-negative bowing multiplier. Default 1.
n_passes: Number of stroke passes. Default 2.
seed: Integer seed. NULL uses getOption("ggsketch.seed", 1L).
arrow_length: Arrowhead length in inches. NULL (default) adapts it to the shaft length.
arrow_angle: Half-angle of the arrowhead in degrees. Default 25.
arrow_type: "open" (default) draws a two-stroke V; "closed" draws a filled rough triangle. Superseded by arrow_head; kept for back-compat.
arrow_head: Arrowhead style, one of sketch_arrowheads(): "triangle_open", "triangle_filled", "barb" (swept harpoon barbs), "fishtail" (forked swallowtail), "dot" (a blob) or "bar" (a perpendicular tick). NULL (default) derives it from arrow_type.
ends: Which end(s) carry a head: "last" (default), "first" or "both" (a double-headed arrow).
family: Font family for the label. Defaults to the same family as theme_sketch() (getOption("ggsketch.base_family", ""), i.e. the device default), so the label matches the plot's other text; set options(ggsketch.base_family = "auto") for a handwriting face, or pass an explicit family here.
label_gap: Gap between the label anchor and the source point, in npc. Default 0.012.
na.rm: Remove missing values silently? Default FALSE.
show.legend: Logical; include in legend? Default FALSE.
inherit.aes: Inherit aesthetics from the plot? Default TRUE.

Details

the shaft curvature defaults to an automatic, pleasing bow whose side follows the direction of travel (curvature = "auto");
the arrowhead is roughened and oriented to the curve's end tangent, so it always points at the target however the shaft bends;
the label justifies itself away from the target, so it never sits under the shaft.

For one-off annotations, annotate_sketch_arrow() is the easiest entry point.

Other sketch-geoms: GeomSketchAbline, GeomSketchBoxplot, GeomSketchBracket, GeomSketchCallout, GeomSketchChicklet, GeomSketchCol, GeomSketchContourFilled, GeomSketchCurve, GeomSketchDotplot, GeomSketchDumbbell, GeomSketchEdge, GeomSketchEllipse, GeomSketchEngrave, GeomSketchGantt, GeomSketchHex, GeomSketchLine, GeomSketchLinerange, GeomSketchLollipop, GeomSketchMarkCircle, GeomSketchMarkHull, GeomSketchPath, GeomSketchPoint, GeomSketchPolygon, GeomSketchRect, GeomSketchRibbon, GeomSketchRug, GeomSketchSegment, GeomSketchSfPolygon, GeomSketchSlope, GeomSketchSmooth, GeomSketchSpoke, GeomSketchTextRepel, GeomSketchViolin, StatSketchBeeswarm, StatSketchCalendar, StatSketchDensityRidges, StatSketchFunnel, StatSketchPie, StatSketchPyramid, StatSketchRadar, StatSketchStream, StatSketchTreemap, StatSketchWaffle, StatSketchWaterfall, annotate_sketch(), annotate_sketch_arrow(), annotate_sketch_callout(), annotate_sketch_highlight(), geom_sketch_alluvial(), geom_sketch_arc_diagram(), geom_sketch_bin2d(), geom_sketch_bump(), geom_sketch_chord(), geom_sketch_contour(), geom_sketch_count(), geom_sketch_dendrogram(), geom_sketch_density(), geom_sketch_density2d(), geom_sketch_ecdf(), geom_sketch_function(), geom_sketch_histogram(), geom_sketch_jitter(), geom_sketch_marimekko(), geom_sketch_mosaic(), geom_sketch_parallel(), geom_sketch_qq(), geom_sketch_quantile(), geom_sketch_rose(), geom_sketch_sunburst(), geom_sketch_text(), sketch_graph()

Examples

Run this code

library(ggplot2)
ggplot(mtcars, aes(wt, mpg)) +
  geom_sketch_point(seed = 1L) +
  annotate_sketch_arrow(x = 4.5, y = 30, xend = 5.25, yend = 18,
                        label = "heavy & thirsty", seed = 2L) +
  theme_sketch()