Extend a discrete colour palette — pal

If the palette returns less colours than requested, the list of colours will be expanded using scales::pal_gradient_n(). To be used with a sequential or diverging palette. Not relevant for qualitative palettes.

Usage

pal_extender(pal = scales::brewer_pal(palette = "BrBG"))

scale_fill_extended(
  name = waiver(),
  ...,
  pal = scales::brewer_pal(palette = "BrBG"),
  aesthetics = "fill"
)

scale_colour_extended(
  name = waiver(),
  ...,
  pal = scales::brewer_pal(palette = "BrBG"),
  aesthetics = "colour"
)

Arguments

pal: A palette function, such as returned by scales::brewer_pal, taking a number of colours as entry and returning a list of colours.
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.
...: Other arguments passed on to discrete_scale() to control name, limits, breaks, labels and so forth.
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").

Value

A palette function.

Examples

pal <- scales::pal_brewer(palette = "PiYG")
scales::show_col(pal(16))
#> Warning: n too large, allowed maximum for palette PiYG is 11
#> Returning the palette you asked for with that many colors

scales::show_col(pal_extender(pal)(16))