HexbinChart
Read a field, a geometry or a spectrum, with the scale handled for you.
@luc/ui/chartsWhat it shows
Show density over a two-dimensional plane without drawing every observation on top of every other.
Live preview
Eight aggregated cells: hexbinning is an aggregation, so the grid is the caller's, not the chart's.
<HexbinChart
cells={[
{ x: -1.2, y: -0.8, value: 6 },
{ x: -0.6, y: -1.1, value: 14 },
{ x: -0.1, y: -0.4, value: 31 },
{ x: 0.3, y: 0.2, value: 42 },
{ x: 0.8, y: 0.6, value: 27 },
{ x: 1.3, y: 1, value: 11 },
{ x: -0.9, y: 0.5, value: 9 },
{ x: 0.6, y: -0.9, value: 18 },
]}
radius={0.22}
valueLabel="Samples"
valueFormat={{ kind: "integer" }}
xFormat={{ kind: "number", decimals: 1 }}
yFormat={{ kind: "number", decimals: 1 }}
height={340}
ariaLabel="Density over a plane"
/>Controls
Height
A chart measures its container, so it always needs a definite height.
State
The surface the chart is in — loading, empty and error are drawn by the component.
Accessible name
A drawing is not readable by a screen reader, so it needs a name that states what it shows.
The same fixture as the live preview above; the controls change how it is drawn, not what it measures.
Code
import { HexbinChart } from "@luc/ui/charts";
<HexbinChart
cells={[
{ x: -1.2, y: -0.8, value: 6 },
{ x: -0.6, y: -1.1, value: 14 },
{ x: -0.1, y: -0.4, value: 31 },
{ x: 0.3, y: 0.2, value: 42 },
{ x: 0.8, y: 0.6, value: 27 },
{ x: 1.3, y: 1, value: 11 },
{ x: -0.9, y: 0.5, value: 9 },
{ x: 0.6, y: -0.9, value: 18 },
]}
radius={0.22}
valueLabel="Samples"
valueFormat={{ kind: "integer" }}
xFormat={{ kind: "number", decimals: 1 }}
yFormat={{ kind: "number", decimals: 1 }}
height={340}
ariaLabel="Density over a plane"
state="ready"
/>Not controllable here
series / rows— The numbers are the caller's; the fixture above is the example.
Copy for an AI agentA specification an agent can act on: the import, the setup, the chosen props, the data contract and the accessibility expectation.
Implement `HexbinChart` from Luc UI. It is: Read a field, a geometry or a spectrum, with the scale handled for you.
Import it with: import { HexbinChart } from "@luc/ui/charts";
Requires: react ^19.0.0; react-dom ^19.0.0; react-hook-form ^7.0.0 (optional, for @luc/ui/forms/react-hook-form); tailwindcss ^4.0.0; node >= 22 (repository tools). Import the stylesheet once at the app root and wrap the tree in `LucProvider`. Both come from the package that publishes @luc.
Chosen configuration: `height={340}`, `state="ready"`, `ariaLabel="Density over a plane"`.
Accessibility: keep the component's own semantics. Do not re-implement its ARIA wiring, do not add roles it does not declare, and make sure every interactive element is reachable and operable from the keyboard with a visible focus state.
Styling: use Luc UI design tokens and the component's own props. Do not restyle with raw colour literals and do not override the component's internal structure with page CSS.
Motion: respect `prefers-reduced-motion`. The component already does, so do not disable it.
Reproduce this state:
```tsx
<HexbinChart
cells={[
{ x: -1.2, y: -0.8, value: 6 },
{ x: -0.6, y: -1.1, value: 14 },
{ x: -0.1, y: -0.4, value: 31 },
{ x: 0.3, y: 0.2, value: 42 },
{ x: 0.8, y: 0.6, value: 27 },
{ x: 1.3, y: 1, value: 11 },
{ x: -0.9, y: 0.5, value: 9 },
{ x: 0.6, y: -0.9, value: 18 },
]}
radius={0.22}
valueLabel="Samples"
valueFormat={{ kind: "integer" }}
xFormat={{ kind: "number", decimals: 1 }}
yFormat={{ kind: "number", decimals: 1 }}
height={340}
ariaLabel="Density over a plane"
state="ready"
/>
```Usage
The values are prepared by the caller: this component draws the points it is given and computes no statistic of its own, so units, scaling and any summary have to be settled before the data reaches it.
It is drawn by the ECharts engine.
Worked examples with real data are on the family overview: Scientific & mathematical
import { HexbinChart } from "@luc/ui/charts";<HexbinChart
cells={[
{ x: -1.2, y: -0.8, value: 6 },
{ x: -0.6, y: -1.1, value: 14 },
{ x: -0.1, y: -0.4, value: 31 },
{ x: 0.3, y: 0.2, value: 42 },
{ x: 0.8, y: 0.6, value: 27 },
{ x: 1.3, y: 1, value: 11 },
{ x: -0.9, y: 0.5, value: 9 },
{ x: 0.6, y: -0.9, value: 18 },
]}
radius={0.22}
valueLabel="Samples"
valueFormat={{ kind: "integer" }}
xFormat={{ kind: "number", decimals: 1 }}
yFormat={{ kind: "number", decimals: 1 }}
height={340}
ariaLabel="Density over a plane"
/>Data contract
`cells` contain the hex centre (`x`, `y`) and aggregated `value`; `radius` sets the hex geometry in axis units. Hexbinning happens upstream, so the chart only draws supplied cells.
Important configuration
Set `radius` to the aggregation resolution, name the aggregate with `valueLabel`, and format x, y and value independently.
Guidelines
When not to use
Do not treat the cell colour as an observation count unless the upstream aggregation actually counted observations.
Configuration
| Export | Kind | Signature |
|---|---|---|
HexbinChart | 16 documented props | ({ cells, radius, valueFormat, xFormat, yFormat, valueLabel, title, description, state, height, className, ariaLabel, ariaDescription, onReady, onEvent, eager, }: HexbinChartProps) => import("@types/… |
HexbinChart props
Type: HexbinChartProps
Values the compiler reads from the declaration.
| Prop | Type | Default | Notes |
|---|---|---|---|
ariaDescription? | string | undefined | — | |
ariaLabel? | string | undefined | — | |
cells | readonly HexbinCell[] | — | |
className? | string | undefined | — | |
description? | string | undefined | — | |
eager? | boolean | undefined | — | Create the engine on mount rather than when the surface is approached. |
height? | string | number | undefined | — | |
onEvent? | ((event: EChartEvent) => void) | undefined | — | |
onReady? | ((chart: EChartsInstance) => void) | undefined | — | |
radius | number | — | Hex radius in axis units (the smoothing is done by the caller). |
state? | ChartState | undefined | — | |
title? | string | undefined | — | |
valueFormat? | ChartFormat | undefined | — | |
valueLabel? | string | undefined | — | Semantic name for the aggregated value, e.g. "Samples". |
xFormat? | ChartFormat | undefined | — | |
yFormat? | ChartFormat | undefined | — |
Accessibility
A chart is a picture of data, so it needs a name that states what it shows, and the numbers must exist as text somewhere on the page — in a table or a written summary — because a drawing is not readable by a screen reader and cannot be copied.
What happens on the server, and when hydration changes it.
Family
Scientific & mathematical
Fields, geometry and spectra for scientific readers.
Related