Menu

Grouped bar

0
2
4
6
8
10
12
14
16
18
1979
1980
1981
1982
1983

A grouped bar chart using the y2 nested dimension. y2 is a band scale whose range is one y band tall, so setting y2="fruit" positions each bar inside its group with no extra code.

This is the server-side rendered version. ssr and percentRange on <LayerCake> put the scales in percentages, so the chart renders before the browser measures it. The axes are HTML components and the marks sit in a <ScaledSvg> that stretches to fit its box. The y2 band is in percent as well, so the bars inside each group share the ScaledSvg's units.

  • +page.svelte
  • ./_components/BarGrouped.svelte
  • ./_components/AxisX.percent-range.html.svelte
  • ./_components/AxisY.percent-range.html.svelte
  • ./_data/yearGroupsLong.js
<script>
  import { LayerCake, ScaledSvg, Html } from 'layercake';
  import { scaleBand } from 'd3-scale';

  import BarGrouped from './_components/BarGrouped.svelte';
  import AxisX from './_components/AxisX.percent-range.html.svelte';
  import AxisY from './_components/AxisY.percent-range.html.svelte';

  // A flat list of rows, one per bar: { year, fruit, value }
  import data from './_data/yearGroupsLong.js';

  const xKey = 'value';
  const yKey = 'year';
  const y2Key = 'fruit';

  const seriesColors = ['#ff00cc', '#00ccff', '#ffcc00'];

  // With `percentRange` on, the y2 band is measured in percent, so the bars inside
  // each group share the ScaledSvg's units.
  // `y2="fruit"` is all it takes to position bars within each group. y2 is a
  // scaleBand by default. Its domain comes from the data and its range is one
  // y band tall. Pass `y2Scale` to customize the padding, for example
  // `y2Scale={scaleBand().paddingInner(0.1)}`. You could also skip `y2` and
  // build that band scale inside your own component.
</script>

<div class="chart-container">
  <LayerCake
    ssr
    percentRange
    padding={{ bottom: 20, left: 35 }}
    x={xKey}
    y={yKey}
    y2={y2Key}
    c={y2Key}
    yScale={scaleBand().paddingInner(0.1)}
    xDomain={[0, null]}
    cRange={seriesColors}
    {data}
  >
    <Html>
      <AxisX tickMarks showBaseline snapLabels gridlines={false} />
      <AxisY tickMarks gridlines={false} />
    </Html>
    <ScaledSvg>
      <BarGrouped />
    </ScaledSvg>
  </LayerCake>
</div>

<style>
  /* Give the wrapper a width and height. LayerCake fills it. */
  .chart-container {
    width: 100%;
    height: 250px;
  }
</style>