demo D216

Heatmap in Svelte

A measure at the crossing of two categories

type: 'heatmap', x, series, y

This draws a heatmap of a measure at the crossing of two categories, with a colour-scale legend showing the low and high of the range. It shows where the highs and lows sit across a grid of combinations, so a pattern across two dimensions reads as colour rather than a table of figures. Switch the ramp scale above the chart between linear, log and quantile and watch the legend redraw to match.

Building…

Loading a live grid…

This is the Svelte version. A use action attaches the grid to a plain element, so no framework runtime is passed in and the component stays small, while the configuration is ordinary Svelte state.

The configuration

<script>
  import { createGrid } from 'https://cdn.latticegrid.dev/lattice-grid@1.107.0/lattice-grid.esm.min.js';
  import createLatticeAction from 'https://cdn.latticegrid.dev/lattice-grid@1.107.0/modules/svelte.esm.min.js';
  import { createChart } from 'https://cdn.latticegrid.dev/lattice-grid@1.107.0/modules/charts.esm.min.js';

  const lattice = createLatticeAction({ createGrid });

  let chartEl;

  const config = {
    rowKey: 'id',
    columns: [
      { field: 'circuit', title: 'Circuit', layout: { width: 180 } },
      { field: 'region', title: 'Region', filter: { type: 'set' } },
      { field: 'status', title: 'Status', filter: { type: 'set' } },
      { field: 'bandwidth', title: 'Bandwidth', type: 'number' },
      { field: 'charge', title: 'Monthly charge', type: 'number',
        format: { style: 'currency', currency: 'GBP' }, total: 'sum' },
    ],
    rows,  // an array of circuit records
    // onGrid hands over the live grid the moment it is created. A heatmap takes
    // two categories, x and series, and a measure, y, at each crossing, and
    // follows the grid's filters and sort.
    onGrid: (grid) => {
      createChart({ grid, container: chartEl, type: 'heatmap',
        x: 'region', series: 'status', y: 'charge', diverging: true });
    },
  };
</script>

<svelte:head>
  <link rel="stylesheet" href="https://cdn.latticegrid.dev/lattice-grid@1.107.0/lattice-grid.min.css">
</svelte:head>

<div bind:this={chartEl} style="height: 340px"></div>
<div use:lattice={config} style="height: 320px; margin-top: 14px"></div>