Discretized Color Scales

Discretized point color

Quantitative point color can create concrete color classes instead of a continuous gradient:

• quantize divides a numeric extent into equal-width intervals.
• quantile derives boundaries that keep observed class counts as even as possible.
• threshold uses an explicit, strictly increasing boundary array. A domain with n boundaries requires n + 1 colors.

program.encodeColor({
  field: "life_expect",
  fieldType: "quantitative",
  scale: {
    type: "threshold",
    domain: [60, 70, 75, 80],
    range: ["#440154", "#3b528b", "#21918c", "#5ec962", "#fde725"]
  }
});

An exact boundary belongs to the upper interval. reverse: true reverses the resolved colors without changing boundaries. createLegend() infers an interval legend with labels such as < 60, 60–70, and ≥ 80. These mappings are available through quantitative point encodeColor and the direct scale vocabulary. A type-changing editScale call validates the complete replacement definition before rematerializing its consumers.

Related

Scale overview · Encodings · Troubleshooting