Rectangle and tile charts with pattern overlays

Drop-in replacements for ggplot2::geom_rect() and ggplot2::geom_tile() that add a pattern aesthetic. Patterns are drawn on top of a filled rectangle and clipped to its bounding box.

Usage

geom_rect_pattern(
  mapping = NULL,
  data = NULL,
  stat = "identity",
  position = "identity",
  ...,
  na.rm = FALSE,
  show.legend = NA,
  inherit.aes = TRUE
)

geom_tile_pattern(
  mapping = NULL,
  data = NULL,
  stat = "identity",
  position = "identity",
  ...,
  width = NULL,
  height = NULL,
  na.rm = FALSE,
  show.legend = NA,
  inherit.aes = TRUE
)

Arguments

mapping: Aesthetic mappings created by ggplot2::aes().
data: Data frame.
stat: Statistical transformation. Default "identity".
position: Position adjustment. Default "identity".
...: Other arguments passed to the layer.
na.rm: If FALSE (default), missing values are removed with a warning.
show.legend: Logical. Should this layer be included in the legend?
inherit.aes: If FALSE, overrides the default aesthetics.
width, height: Tile width and height in data units. If NULL (default), computed as the resolution of x/y.

Value

A ggplot2 layer.

Details

geom_rect_pattern() requires explicit corner aesthetics (xmin, xmax, ymin, ymax). geom_tile_pattern() accepts center + size aesthetics (x, y plus optional width and height; widths/heights default to the resolution of the x/y values so tiles tessellate without gaps).

Pattern aesthetics

pattern: Character name of the pattern. One of "none", "hatch", "crosshatch", "horizontal", "vertical", "dots", "weave", or a custom pattern registered with register_pattern(). Each base pattern (except "none") also has _dense and _sparse variants (e.g. "hatch_dense", "dots_sparse") for pre-set tighter or looser spacing.
pattern_colour: Colour of pattern lines/dots. Default "black".
pattern_linewidth: Line width for line-based patterns. Default 1.
pattern_spacing: Spacing between pattern elements in millimetres. Default 5. Smaller values produce denser patterns; larger values produce sparser patterns. Named density variants (e.g. "hatch_dense") bake in a pre-set spacing multiplier but still respect explicit pattern_spacing values.
pattern_angle: Angle in degrees for hatch patterns. Default 45.
pattern_size: Dot radius in millimetres for the "dots" pattern. Default 0.5.

Examples

library(ggplot2)

# Explicit corner coordinates
df <- data.frame(
  xmin = c(0, 1, 2), xmax = c(0.8, 1.8, 2.8),
  ymin = 0, ymax = c(1, 3, 2),
  pattern = c("hatch", "crosshatch", "dots")
)
ggplot(df, aes(xmin = xmin, xmax = xmax, ymin = ymin, ymax = ymax,
               fill = pattern, pattern = pattern)) +
  geom_rect_pattern() +
  scale_pattern_identity() +
  scale_fill_brewer(palette = "Pastel1") +
  theme_minimal()


# Heatmap-style tile chart
df2 <- expand.grid(x = 1:4, y = 1:4)
df2$pattern <- rep(c("hatch", "crosshatch", "dots", "none"), 4)
df2$fill_g  <- rep(letters[1:4], each = 4)
ggplot(df2, aes(x, y, fill = fill_g, pattern = pattern)) +
  geom_tile_pattern() +
  scale_pattern_identity() +
  scale_fill_brewer(palette = "Pastel2") +
  theme_minimal()