scale-fill-discrete

Discrete fill scale mapping categorical levels to fill colours.

Usage

scale-fill-discrete(
  name,
  palette,
  limits,
  oob,
  labels,
)

Parameters

Parameter	Default	Description
`name`		Legend title. Overrides any name set via `labels` when both are present.
`palette`		Colour source: an array of colours, or `auto`.
`limits`		Array of level names controlling order and inclusion, or `none`.
`oob`		Out-of-range policy: `"drop"` (default) removes rows whose value falls outside `limits`; `"squish"` clamps continuous values to the nearest endpoint.
`labels`		Array of legend labels aligned with `limits`, or `auto`.

Returns

Scale object consumed by plot.

Examples

Default palette filling three bars from the library’s reserved discrete colours.

#let d = (
  (grp: "a", y: 1),
  (grp: "b", y: 2),
  (grp: "c", y: 3),
)
#plot(
  data: d,
  mapping: aes(x: "grp", y: "y", fill: "grp"),
  layers: (geom-col(),),
  scales: (scale-fill-discrete(),),
  width: 10cm,
  height: 6cm,
)

The palette laid out as a swatch strip via geom-rect, one rectangle per level.

#let levels = ("a", "b", "c", "d", "e", "f", "g", "h")
#let d = levels.enumerate().map(((i, k)) => (
  xmin: i, xmax: i + 1, ymin: 0, ymax: 1, k: k,
))
#plot(
  data: d,
  mapping: aes(xmin: "xmin", xmax: "xmax", ymin: "ymin", ymax: "ymax", fill: "k"),
  layers: (geom-rect(),),
  scales: (scale-fill-discrete(),),
  guides: guides(fill: none),
  theme: theme-void(),
  width: 8cm,
  height: 1cm,
)

See also

scale-fill-manual, scale-fill-viridis-d, scale-colour-discrete.