Channel

Channel = "x" | "x2" | "y" | "y2" | "z" | "theta" | "theta2" | "radius" | "radius2" | "longitude" | "latitude" | "geometry" | "color" | "fill" | "stroke" | "strokeWidth" | "size" | "shape" | "opacity" | "text" | "tooltip" | "source" | "target" | "detail" | "order" | "key" | "row" | "column"

Defined in: spec/channel.ts:7

A visual property a field can drive.

The channel set is what makes the catalogue open: a heatmap needs no new type, only x/y categorical plus color quantitative.