scale-colour-gradient

Continuous two-stop colour gradient.

Linearly interpolates between low and high across the trained domain. Defaults to a blue ramp.

Usage

scale-colour-gradient(
  low,
  high,
  name,
  limits,
  oob,
  breaks,
  labels,
)

Parameters

Parameter	Default	Description
low		Colour for the low end of the domain.
high		Colour for the high end of the domain.
name		Legend title. Overrides any name set via labels when both are present.
limits		Pair (lo, hi) clipping the trained domain, or none.
oob		Out-of-range policy: "drop" (default) removes rows whose value falls outside limits; "squish" clamps continuous values to the nearest endpoint.
breaks		Array of break values for the legend, or auto.
labels		Array of legend labels aligned with breaks, or auto.

Returns

Scale object consumed by plot.

Examples

Default low-to-high blue ramp.

#let d = range(0, 12).map(i => (x: i, y: i, z: i * 0.5))
#plot(
  data: d,
  mapping: aes(x: "x", y: "y", colour: "z"),
  layers: (geom-point(size: 3pt),),
  scales: (scale-colour-gradient(),),
  width: 10cm,
  height: 6cm,
)

Custom two-stop ramp passing explicit low and high colours.

#let d = range(0, 12).map(i => (x: i, y: i, z: i * 0.5))
#plot(
  data: d,
  mapping: aes(x: "x", y: "y", colour: "z"),
  layers: (geom-point(size: 3pt),),
  scales: (scale-colour-gradient(
    low: rgb("#fee5d9"),
    high: rgb("#a50f15"),
  ),),
  width: 10cm,
  height: 6cm,
)

See also

scale-colour-gradient2, scale-colour-gradientn, scale-fill-gradient.