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Scale for draw aesthetic

Source: R/geom-draw2.R
scale_draw_manual.Rd

Draw a ggplot2 layer using a grob or a function.

Usage

scale_draw_manual(
  ...,
  values,
  aesthetics = "draw",
  breaks = waiver(),
  na.value = NA
)

Arguments

...

Arguments passed on to ggplot2::discrete_scale

name

The name of the scale. Used as the axis or legend title. If waiver(), the default, the name of the scale is taken from the first mapping used for that aesthetic. If NULL, the legend title will be omitted.

labels

One of:

  • NULL for no labels

  • waiver() for the default labels computed by the transformation object

  • A character vector giving labels (must be same length as breaks)

  • An expression vector (must be the same length as breaks). See ?plotmath for details.

  • A function that takes the breaks as input and returns labels as output. Also accepts rlang lambda function notation.

limits

One of:

  • NULL to use the default scale values

  • A character vector that defines possible values of the scale and their order

  • A function that accepts the existing (automatic) values and returns new ones. Also accepts rlang lambda function notation.

na.translate

Unlike continuous scales, discrete scales can easily show missing values, and do so by default. If you want to remove missing values from a discrete scale, specify na.translate = FALSE.

drop

Should unused factor levels be omitted from the scale? The default, TRUE, uses the levels that appear in the data; FALSE includes the levels in the factor. Please note that to display every level in a legend, the layer should use show.legend = TRUE.

guide

A function used to create a guide or its name. See guides() for more information.

call

The call used to construct the scale for reporting messages.

super

The super class to use for the constructed scale

values

A list of functions (including purrr-like lambda syntax) that define how each cell's grob (graphical object) should be drawn.

aesthetics

Character string or vector of character strings listing the name(s) of the aesthetic(s) that this scale works with. This can be useful, for example, to apply colour settings to the colour and fill aesthetics at the same time, via aesthetics = c("colour", "fill").

breaks

One of:

  • NULL for no breaks

  • waiver() for the default breaks (the scale limits)

  • A character vector of breaks

  • A function that takes the limits as input and returns breaks as output

na.value

The aesthetic value to use for missing (NA) values

Details

If you want to combine the functionality of multiple geoms, it can typically be achieved by preparing the data for each geom inside the draw_*() call and sending it off to the different geoms, collecting the output in a grid::gList (a list of grobs) for draw_group() or a grid::gTree (a grob containing multiple child grobs) for draw_panel().

See also

https://ggplot2.tidyverse.org/reference/ggplot2-ggproto.html

Examples

text <- grid::textGrob(
    "ggdraw",
    x = c(0, 0, 0.5, 1, 1),
    y = c(0, 1, 0.5, 0, 1),
    hjust = c(0, 0, 0.5, 1, 1),
    vjust = c(0, 1, 0.5, 0, 1)
)
ggplot(data.frame(x = 1, y = 2)) +
    geom_draw(text)