Marks
The building blocks of every chart.
A mark is a visual encoding – bars, lines, dots, areas, text, rules. Each entry in the marks array draws one layer. Later marks draw on top of earlier ones.
Mark types
Bar
barY and barX, stacking and dodging.
Line
Single and multi-series lines.
Dot
Scatter plots and point marks.
Area
areaY and areaX, stacked areas.
Text
Data labels and annotations.
Rule
ruleX and ruleY reference lines.
Shared properties
Every mark accepts:
| Field | Type | Default | Description |
|---|---|---|---|
type | string | – | Required. The mark type. |
data | Datum[] | – | Mark-specific data. Overrides top-level data. |
x | string | "x" | Field name for x position. |
y | string | "y" | Field name for y position. |
fill | string | – | Fill color: field name for color scale, or #hex literal. |
stroke | string | – | Stroke color: field name for color scale, or #hex literal. |
strokeWidth | number | 1 | Stroke width in pixels. |
Composition
Layer marks to build richer charts. A scatter plot with quadrant lines is just dot + ruleX + ruleY. A bar chart with value labels is barY + text:
The quadrant lines divide features into high-impact/low-effort (top-left) vs low-impact/high-effort (bottom-right). Three marks, one config.