Scales

Scales map abstract values such as time or temperature to a visual values such as x- or y-position or color.

A scale is primarily defined by its input domain and output range.

Scales with continuous domain and range are called quantitative scales. The scale can be linear, logarithmic, etc.

Scales with a discrete domain of categorical values that map to a continuous range are called ordinal scales. Discrete color scales can either be ordinal when the data are ordered and categorical otherwise.

Scale Properties

(scale,channel) : The scale channel. One of x, y, color, size, shape, or text. Same as the encoding channel.

(scale,type) : The scale type. One of linear, log, ordinal, or categorical.

Example

attribute((scale,channel),s,x).
attribute((scale,type),s,linear).

attribute((scale,channel),s,color).
attribute((scale,type),s,categorical).