Chart vocabulary

Annotation

Explanatory content placed in data coordinates, such as a reference line, band, point, arrow, or fitted trend.

Axis

The visible line, ticks, labels, and title that communicate a positional scale.

Channel

A visual property that can carry data, such as x-position, y-position, color, size, shape, or text.

Domain

The input values covered by a scale. A numeric x-domain might run from 0 to 100; a categorical domain is an ordered set of names.

Encoding

A mapping from a data column to a visual channel. For example, encode(x=year, y=revenue) maps two columns to position.

Facet

One cell in a grid of independent plots. Facets may use independent scales or a supported shared y-scale.

Layer

One plot drawn in the same coordinate frame as other plots. Compatible layers share an x-domain and either a primary or secondary y-axis.

Legend

A key connecting colors, sizes, shapes, or named layers to their meaning.

Mark

The geometric form used to represent data, such as a point, line, bar, area, box, or arc.

Plot

The builder value containing a mark, encoded data, labels, annotations, scale settings, theme, and output size.

Raster

Pixel-based output. Dataviz writes PNG and BMP raster files.

Scale

A mapping from a data domain to a visual range, such as numeric values to pixel positions or colors.

Secondary axis

An independent y-scale drawn on the right side of a layered chart for a series with different units.

Theme

Presentation settings for canvas, axes, typography, marks, legends, annotations, and output.

SVG

Vector output represented as XML shapes and text. It scales cleanly and can include accessibility metadata and tooltips.

Continue with the Guides, browse chart types in Examples, or look up exact contracts in the API reference.