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Documentation for Layer Cake v10, before Svelte 5 runes. Current docs at layercake.graphics

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Scatter (svg + canvas + voronoi)

A scatter plot with three layers: SVG axes, canvas circles and a second SVG layer with smaller circles on top. A Voronoi layer over everything reports the nearest point on hover. Open the console and move the mouse to see it.

  • +page.svelte
  • ./_components/Scatter.svg.svelte
  • ./_components/Scatter.canvas.svelte
  • ./_components/Voronoi.svelte
  • ./_components/AxisX.svelte
  • ./_components/AxisY.svelte
  • ./_data/points.csv
<script>
  import { LayerCake, Svg, Canvas } from 'layercake';

  import ScatterSvg from './_components/Scatter.svg.svelte';
  import ScatterCanvas from './_components/Scatter.canvas.svelte';
  import Voronoi from './_components/Voronoi.svelte';
  import AxisX from './_components/AxisX.svelte';
  import AxisY from './_components/AxisY.svelte';

  // The CSV rows are parsed, and their numbers typed, by @rollup/plugin-dsv. See vite.config.js
  import data from './_data/points.csv';

  const xKey = 'myX';
  const yKey = 'myY';

  const r = 3;
  const scalePadding = 10;

  // The Voronoi layer reports the point under the mouse. Its row is on `point.data`.
  /** @param {MouseEvent} e @param {any} point */
  function logPoint(e, point) {
    console.log(point.data);
  }
</script>

<div class="chart-container">
  <LayerCake
    padding={{ top: 10, right: 5, bottom: 20, left: 25 }}
    x={xKey}
    y={yKey}
    xPadding={[scalePadding, scalePadding]}
    yPadding={[scalePadding, scalePadding]}
    {data}
  >
    <Svg>
      <AxisX gridlines={false} />
      <AxisY gridlines={false} ticks={4} />
    </Svg>

    <Canvas>
      <ScatterCanvas r={r * 1.5} fill="#00ccff" />
    </Canvas>

    <Svg>
      <ScatterSvg {r} fill="#fff" />
      <Voronoi stroke="#333" onmouseover={logPoint} />
    </Svg>
  </LayerCake>
</div>

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