# BubbleRow (/docs/charts/bubble-row)

BubbleRow answers "roughly how do these few magnitudes compare?" with physical presence — a row of circles whose
**area** (not width) is proportional to value. Area is the weakest common channel, so this is the catalog's honest
low-precision exemplar: **for a precise comparison, use `MiniBar`.** The value numerals are on by default, because a
low-precision channel owes the reader the number.

```tsx
<BubbleRow
  data={[
    { label: "EMEA", value: 1240 },
    { label: "AMER", value: 890 },
    { label: "APAC", value: 560 },
    { label: "LATAM", value: 210 },
  ]}
  title="Market size"
  height={36}
/>
```

## Install

```tsx
import { BubbleRow } from "@microcharts/react/bubble-row";

<BubbleRow data={regions} title="Market size" />
```

Setup (package + stylesheet): [Quickstart](/docs/quickstart#set-up-with-an-ai-agent) or paste [`/agent-setup.md`](/agent-setup.md) into your agent.


## When to use it

- **Good for** — a few magnitudes with physical presence in a sentence, a market-size or segment impression in a KPI
  card, or an editorial callout where the number is printed too.
- **Avoid for** — precise comparison (that's `MiniBar`), trends (Sparkline), or more than about eight items.


## Variants

```tsx
<BubbleRow data={regions} align="baseline" />
<BubbleRow data={regions} label="both" />
```

## Edge cases

```tsx
<BubbleRow data={[]} title="No regions" />
```

```tsx
<BubbleRow data={[{ label: "EMEA", value: 1240 }, { label: "AMER", value: null }]} />
```

Empty data draws just the frame with "No data." as the summary. A `null` value still holds its place with a small
presence ring (never a zero-radius void, and never skipped from the row) but drops its numeral — a missing figure is
visibly present yet explicitly unlabeled, never faked as a zero.


## Why this default

Value numerals are on by default because area lies quietly — a bubble twice the diameter is four times the area, and the
eye can't reliably invert that, so the number keeps the read honest. The radius is always `r ∝ √value` with no
exceptions; a linear-radius map would be a roughly squared lie. There is no sorting prop: the order is your data's
order, because reordering is your statement, not the chart's. The LOW precision rating and the MiniBar steer are printed
in the catalog, the machine `/catalog.json`, and this page's header — BubbleRow is the catalog's worked example of an
honest low-precision admission.

## Accessibility

The accessible name names the extremes — **"4 items; largest EMEA at 1,240, smallest LATAM at 210."** The interactive
entry roves the bubbles with ←/→ (or hover), announcing each one's exact value — **"EMEA: 1,240."** — the number the
area itself can't carry.

The interactive entry follows the shared [interaction contract](/docs/accessibility#one-interaction-contract):
arrow keys rove between units on both axes, `Home` and `End` jump to the ends, and a click, tap, `Enter` or
`Space` selects a unit — pinning its readout so it survives blur, until you select it again or press `Escape`.
On touch, a tap pins and a drag scrubs.

## Props

| Prop | Type | Description |
| --- | --- | --- |
| `data` (required) | `{ label, value }[]` | A few non-negative magnitudes. |
| `align` | `"center" \| "baseline"` | center (specimen) or baseline (weights on a shelf). |
| `label` | `"value" \| "both" \| "none"` | value (default), both, or none. |
| `animate` | `boolean` | (interactive) Opt-in entrance motion when the chart mounts client-side — add `import "@microcharts/react/motion"` once. Inert on the server, on hydrated server HTML, and under `prefers-reduced-motion`. |

Plus the shared grammar — `data`, `domain`, `color`, `title`, `summary`, `format` — and the layout props (`width`, `height`, `className`, `style`) that every chart accepts. Interactive entries also share `animate` and `live`, and — wherever a chart has more than one navigable unit — `onActive`, `onSelect`, `selectedIndex` and `defaultSelectedIndex`; and — wherever the chart shows a hover value — `readout`. See [the shared grammar](/docs/quickstart#the-shared-grammar).