Heatmap

Two-dimensional categorical heatmap with z-axis color scale.

Map a numeric value to color for every combination of two categorical axes. Supply x/y category lists plus [x_index, y_index, value] cell tuples, then tune the color scale on the z axis.

Calendar grids, correlation matrices, or category × metric intensity tables.
Severity or utilization bands via piecewise color_scale thresholds.
Dashboard cells where exact values matter on hover — enable tooltip.

Pass x_categories, y_categories, and sparse or dense cells tuples (0-based indexes).
Set color_scale to continuous (default) or piecewise for severity buckets.
Enable legend for a color-bar key; tooltip for per-cell values.
Wrap the chart in a native element with data-testid for E2E hooks.

Basic heatmap

Region × hour grid with default continuous color scale. Tuple indexes refer to positions in the category arrays — sparse tuples omit empty cells.

Piecewise color scale

Bucketed colors via thresholds for low/medium/high severity. Thresholds split the z domain into bands — each band maps to the next color in colors.