Annotate a shaded panel region

Draws a filled rectangle over the panel with colour defaults taken from the set theme. Defaults to a subtle overlay across the full panel, with the fill automatically adapting to light or dark panel backgrounds. Should be placed before geom layers.

Usage

panel_shade(
  ...,
  xmin = -Inf,
  xmax = Inf,
  ymin = -Inf,
  ymax = Inf,
  fill = "#878580",
  alpha = 0.25,
  colour = "transparent",
  linewidth = NULL,
  linetype = NULL
)

Arguments

...

Not used. Allows trailing commas and named-argument style calls.

xmin, xmax

Left and right edges of the rectangle. Defaults to -Inf and Inf. Use I() for normalized coordinates (0-1).

ymin, ymax

Bottom and top edges of the rectangle. Defaults to -Inf and Inf. Use I() for normalized coordinates (0-1).

fill

Fill colour. Defaults to a neutral grey.

alpha

Opacity of the rectangle. Defaults to 0.25.

colour

Border colour. Defaults to "transparent".

linewidth

Inherits from panel.border in the set theme. Supports rel().

linetype

Border linetype. Defaults to 1.

Value

A list containing an annotation layer.

Examples

library(ggplot2)
library(dplyr)

set_theme(
  ggrefine::theme_grey(
    panel_heights = rep(unit(50, "mm"), 100),
    panel_widths = rep(unit(75, "mm"), 100),
  )
)

mtcars |>
  ggplot(aes(x = wt, y = mpg, colour = as.factor(gear), fill = as.factor(gear))) +
  scale_colour_discrete(palette = blends::multiply(get_theme()$palette.colour.discrete)) +
  #clip = "off" is required for axis_text, axis_ticks and axis_bracket
  coord_cartesian(clip = "off") +
  #reference lines and shade
  ggscribe::reference_line(xintercept = 2.4) +
  ggscribe::reference_line(yintercept = 12)  +
  ggscribe::panel_shade(
    xmin = 4,
    xmax = 5,
  ) +
  #top axis
  scale_x_continuous(
    sec.axis = ggscribe::sec_axis_text(
      breaks = c(mean(c(4, 5))),
      labels = c("Range"),
      guide = ggscribe::guide_sec_axis_text(
        angle = 90,
      )
    )
  ) +
  ggscribe::axis_bracket(
    position = "top",
    breaks = c(4, 5),
  ) +
  ggscribe::axis_text(
    position = "top",
    breaks = c(2.4),
    labels = c("Threshold"),
  ) +
  #right axis
  ggscribe::axis_text(
    position = "right",
    breaks = 12,
    labels = "Threshold",
  ) +
  #'geom
  geom_point() +
  #annotations fit plot
  theme(plot.background = element_rect(colour = "grey92"))