Scientific & mathematicalGenerated from the public API

ThemeRiverChart

Read a field, a geometry or a spectrum, with the scale handled for you.

@luc/ui/charts

What it shows

Show how several categorical quantities change and cross through ordered periods as a flowing stacked field.

Live preview

Four quarters of supply-and-demand facts; the engine lays out the bands, the numbers are the caller's.

<ThemeRiverChart
  events={[
    { date: "2026-01-01", name: "Trend", value: 42 },
    { date: "2026-01-01", name: "Carry", value: 18 },
    { date: "2026-01-01", name: "Value", value: 11 },
    { date: "2026-04-01", name: "Trend", value: 51 },
    { date: "2026-04-01", name: "Carry", value: 14 },
    { date: "2026-04-01", name: "Value", value: 22 },
    { date: "2026-07-01", name: "Trend", value: 34 },
    { date: "2026-07-01", name: "Carry", value: 13 },
    { date: "2026-07-01", name: "Value", value: 31 },
    { date: "2026-10-01", name: "Trend", value: 22 },
    { date: "2026-10-01", name: "Carry", value: 15 },
    { date: "2026-10-01", name: "Value", value: 18 },
  ]}
  format={{ kind: "number", decimals: 0, suffix: " bps" }}
  height={360}
  ariaLabel="Contribution by source"
/>

Controls

Height

360px

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 { ThemeRiverChart } from "@luc/ui/charts";

<ThemeRiverChart
  events={[
    { date: "2026-01-01", name: "Trend", value: 42 },
    { date: "2026-01-01", name: "Carry", value: 18 },
    { date: "2026-01-01", name: "Value", value: 11 },
    { date: "2026-04-01", name: "Trend", value: 51 },
    { date: "2026-04-01", name: "Carry", value: 14 },
    { date: "2026-04-01", name: "Value", value: 22 },
    { date: "2026-07-01", name: "Trend", value: 34 },
    { date: "2026-07-01", name: "Carry", value: 13 },
    { date: "2026-07-01", name: "Value", value: 31 },
    { date: "2026-10-01", name: "Trend", value: 22 },
    { date: "2026-10-01", name: "Carry", value: 15 },
    { date: "2026-10-01", name: "Value", value: 18 },
  ]}
  format={{ kind: "number", decimals: 0, suffix: " bps" }}
  height={360}
  ariaLabel="Contribution by source"
  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 `ThemeRiverChart` from Luc UI. It is: Read a field, a geometry or a spectrum, with the scale handled for you.

Import it with: import { ThemeRiverChart } 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={360}`, `state="ready"`, `ariaLabel="Contribution by source"`.

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
<ThemeRiverChart
  events={[
    { date: "2026-01-01", name: "Trend", value: 42 },
    { date: "2026-01-01", name: "Carry", value: 18 },
    { date: "2026-01-01", name: "Value", value: 11 },
    { date: "2026-04-01", name: "Trend", value: 51 },
    { date: "2026-04-01", name: "Carry", value: 14 },
    { date: "2026-04-01", name: "Value", value: 22 },
    { date: "2026-07-01", name: "Trend", value: 34 },
    { date: "2026-07-01", name: "Carry", value: 13 },
    { date: "2026-07-01", name: "Value", value: 31 },
    { date: "2026-10-01", name: "Trend", value: 22 },
    { date: "2026-10-01", name: "Carry", value: 15 },
    { date: "2026-10-01", name: "Value", value: 18 },
  ]}
  format={{ kind: "number", decimals: 0, suffix: " bps" }}
  height={360}
  ariaLabel="Contribution by source"
  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 { ThemeRiverChart } from "@luc/ui/charts";

<ThemeRiverChart
  events={[
    { date: "2026-01-01", name: "Trend", value: 42 },
    { date: "2026-01-01", name: "Carry", value: 18 },
    { date: "2026-01-01", name: "Value", value: 11 },
    { date: "2026-04-01", name: "Trend", value: 51 },
    { date: "2026-04-01", name: "Carry", value: 14 },
    { date: "2026-04-01", name: "Value", value: 22 },
    { date: "2026-07-01", name: "Trend", value: 34 },
    { date: "2026-07-01", name: "Carry", value: 13 },
    { date: "2026-07-01", name: "Value", value: 31 },
    { date: "2026-10-01", name: "Trend", value: 22 },
    { date: "2026-10-01", name: "Carry", value: 15 },
    { date: "2026-10-01", name: "Value", value: 18 },
  ]}
  format={{ kind: "number", decimals: 0, suffix: " bps" }}
  height={360}
  ariaLabel="Contribution by source"
/>

Data contract

`events` is an ordered list of `{ date, name, value }` facts, one stream per category; `format` describes the quantity. The engine lays out the bands but does not derive the facts.

Important configuration

Keep a consistent category order across periods, format the quantity, and state whether the stream width is additive across categories.

Guidelines

When not to use

Do not use a theme river for independent series that do not share a meaningful total or for a precise ranking of close values.

Configuration

Exported symbols
Export	Kind	Signature
`ThemeRiverChart`	12 documented props	`({ events, format, title, description, state, height, className, ariaLabel, ariaDescription, onReady, onEvent, eager, }: ThemeRiverChartProps) => import("@types/react").JSX.Element`