Color Mapping (discrete)

Maps categorical values to colors.

Usage

palette_color_discrete(
  colors = NULL,
  domain = NULL,
  ordered = FALSE,
  missing = "#DDDDDD"
)

palette_colour_discrete(
  colors = NULL,
  domain = NULL,
  ordered = FALSE,
  missing = "#DDDDDD"
)

Arguments

colors

A vector of colors or a function that when called with a single argument (an integer specifying the number of colors) returns a vector of colors. If NULL (the default), uses discrete rainbow.

domain

A vector of categorical data specifying the possible values that can be mapped.

ordered

A logical scalar: should the levels be treated as already in the correct order?

missing

The color to return for NA values.

Value

A palette function that when called with a single argument (a vector of categorical values) returns a character vector of colors.

See also

Other palettes: palette_color_continuous(), palette_color_picker(), palette_shape(), palette_size

Examples

## Scatter plot
## Build color palette functions
bright <- c(versicolor = "#4477AA", virginica = "#EE6677", setosa = "#228833")
pal_color <- palette_color_discrete(colors = bright)

## Build symbol palette functions
symbols <- c(versicolor = 15, virginica = 16, setosa = 17)
pal_shapes <- palette_shape(symbols)

## Plot
plot(
  x = iris$Petal.Length,
  y = iris$Sepal.Length,
  pch = pal_shapes(iris$Species),
  col = pal_color(iris$Species),
  xlab = "Petal length",
  ylab = "Sepal length",
  panel.first = grid(),
  las = 1
)
legend("topleft", legend = names(bright), col = bright, pch = symbols)