Heatmap · Intensity classes

The scale classifies original values without turning classes into series.

Use for a measurement at each pair of categories, such as day and shift. For precise values, use the tooltip or source data. Colour expresses intensity; cell size does not represent a second measure.

Declare category X/Y axes with stable IDs, optional labels and optional reversed order. Each cell declares id, rowId, columnId and value:number|null. Zero and negative numbers stay known; null is explicitly unknown. An absent coordinate creates no cell. Duplicate IDs, duplicate coordinates and unknown categories are rejected. Limits are 64 categories per axis and 4,096 original cells.

layout.gapRatio controls spacing from 0 to 0.5. appearance.opacity accepts 0–1; minPlotWidth enables plot-only scrolling. colorAxis.scale supports continuous stops/domain or ordered classes; visible controls the quantitative legend. Titles, axes, data labels, tooltip placement/pinning and motion have typed options. There is no series visibility legend, numeric viewport zoom, stacking, crosshair or per-cell paint override.

• Activity by day and shift
• Unknown and absent
• Intensity classes
• Reversed axes
• Activity calendar
• Wide matrix

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