Published-release documentation · release compatibility

Scale Missing Values

Missing and invalid values

Point encodings can provide an unknown fallback inside their scale options:

Contextual fragment. Use an ES module with the imports, data, and prepared resource state described in this section. Caller-provided receivers: program. Resolve these names from setup in this fragment or section; alternatives branch from the same base.

program.encodeX({
  field: "value",
  scale: { domain: [0, 100], unknown: 20 }
});

The fallback is used for a missing or field-type-invalid input. For ordinal point position or appearance, it also handles a value outside an explicit domain. It never becomes a domain member. Output validation follows the channel: position uses a finite coordinate, color a non-empty string, size a non-negative area, opacity a value from 0 to 1, and shape one supported point shape.

Missing or invalid row fallback is limited to row-owned point items, with one separate line-color policy: a Cartesian line with nominal/ordinal color and an explicit nonempty ordinal domain can use an unknown paint while preserving raw series identities. Missing and null colors use that paint; malformed category objects, arrays and non-finite numbers still fail.

Cartesian line and rule stroke-dash scales support unknown for valid raw categories outside a domain. The fallback is a named dash style or direct pattern, including [] for a solid stroke. It does not permit missing or invalid categories, add domain or legend entries, or merge different raw series. Parallel, polar, aggregate and binned path topologies reject this fallback. See Ordinal and stroke dash scales.

Other grouped and aggregate consumers retain their existing strict policy. A direct unattached scale stores its fallback and defers channel validation until attachment. Set unknown: undefined with editScale to remove an existing fallback. The edit fails atomically if any dependent consumer would become invalid. The focused editStrokeDashScale supports the same removal.

Related

Scale overview · Encodings · Troubleshooting