# Population explorer (Unit example)

> WestCoast Charts 1.1.5, release, public Core release, on npm. HTML: https://westcoast-charts.com/gallery/unit/population-explorer/ · Index for agents: https://westcoast-charts.com/llms.txt

Switch the grouping; the same marks fly to their new clusters.

Why it matters: 'flow' transition: the crowd migrates and recolours between groupings with spring motion; reduced-motion places instantly

- Chart type: `unit` (Unit)
- Collection: Unit · Unit & pictogram
- Raw configuration: https://westcoast-charts.com/gallery-src/unit/population-explorer.js
- Standalone example: https://westcoast-charts.com/embed/samples/wcc/gallery/unit/population-explorer.html

## Setup

```js
import WestCoastCharts from 'west-coast-charts'
import types from 'west-coast-charts/types'

WestCoastCharts.use(types)
```

## Options

```js
const options = {
  chart: {
    height: 400,
    fontFamily: "Inter, Geist, \"IBM Plex Sans\", system-ui, sans-serif",
    type: "unit",
    toolbar: {
      show: false
    }
  },
  series: [64, 118, 92, 46],
  labels: ["0-17", "18-39", "40-64", "65+"],
  plotOptions: {
    unit: {
      transition: "flow",
      gather: {
        motion: "spring",
        spring: "gentle"
      },
      clusterLabels: {
        show: true
      }
    }
  },
  title: {
    text: "A city of 320 residents"
  },
  theme: {
    mode: "light",
    preset: "coastal"
  }
}

const chart = new WestCoastCharts(document.querySelector('#chart'), options)
await chart.render()
```

## Verify

- Text check (Library 1.1.5): load `west-coast-charts/agent/describe` and call `chart.describe({ format: "json" })` for the actual drawn state. The live reader is on this example’s HTML page.
- Command line (Public agent tools 0.2.3, tested with Library 1.1.5; available from the versioned GitHub release and npm, https://westcoast-charts.com/docs/cli/index.md): `wcc chart export unit-population-explorer.json --out unit-population-explorer.svg --with-table` (save the options above as JSON first)