Colour scales

Declare a colour scale for the color/fill channel. Continuous data get a perceptual ramp; discrete data get a qualitative palette. scale_*_manual() sets exact colours, scale_*_gradient() a two-point ramp. The fill variants are identical (colour and fill share one scale). A legend is drawn automatically when colour is mapped.

Usage

scale_color_continuous(
  plot,
  palette = NULL,
  breaks = NULL,
  labels = NULL,
  name = NULL
)

scale_color_discrete(
  plot,
  palette = NULL,
  breaks = NULL,
  labels = NULL,
  name = NULL
)

scale_color_manual(plot, values, name = NULL)

scale_color_gradient(plot, low = "#132B43", high = "#56B1F7", name = NULL)

scale_fill_continuous(
  plot,
  palette = NULL,
  breaks = NULL,
  labels = NULL,
  name = NULL
)

scale_fill_discrete(
  plot,
  palette = NULL,
  breaks = NULL,
  labels = NULL,
  name = NULL
)

scale_fill_manual(plot, values, name = NULL)

scale_fill_gradient(plot, low = "#132B43", high = "#56B1F7", name = NULL)

scale_colour_continuous(
  plot,
  palette = NULL,
  breaks = NULL,
  labels = NULL,
  name = NULL
)

scale_colour_discrete(
  plot,
  palette = NULL,
  breaks = NULL,
  labels = NULL,
  name = NULL
)

scale_colour_manual(plot, values, name = NULL)

scale_colour_gradient(plot, low = "#132B43", high = "#56B1F7", name = NULL)

Arguments

plot

A PlotSpec.

palette

A vector of colours, or a single palette name passed to grDevices::hcl.colors() (e.g. "Batlow", "Blues", "Set 2"; matched case/space-insensitively). NULL uses a sensible default.

breaks, labels

Explicit legend breaks / labels, or NULL.

name

Legend title, or NULL to derive from the encoding.

values

For scale_*_manual(), a vector of colours; if named, matched to data levels by name (unmatched levels draw grey).

low, high

For scale_*_gradient(), the endpoint colours.

Value

The modified PlotSpec.

Examples

vplot(mtcars) |>
  mark_point(x = wt, y = mpg, color = hp) |>
  scale_color_continuous(palette = "Batlow")