demo D279

A trend line and a forecast in ESM

Draw a least-squares trend straight through the points and carry it on as a dashed forecast, with a vertical event marker flagging the day a change went live

trend: { method: 'linear', forecast: 8 }

This draws a least-squares trend straight through the points and carries it on as a dashed forecast, with a vertical marker flagging the day a change went live. It shows where a series is heading and lets you see whether an event bent the line.

Building…

Loading a live grid…

This is the ES module version. The grid is imported straight from a CDN as a module, the same configuration as the vanilla tab without a global script tag, so it drops into any bundler or a bare module script.

The configuration

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/@toclocoinc/lattice-grid@1.71.0/lattice-grid.min.css">

<div id="grid" style="height: 320px"></div>
<div id="chart" style="height: 300px"></div>

<script type="module">
  import { createChart } from '@toclocoinc/lattice-grid/modules/charts';

  const grid = createGrid(document.getElementById('grid'), {
    rowKey: 'id',
    columns: [
      { field: 'day', title: 'Day', type: 'number' },
      { field: 'active', title: 'Active users', type: 'number', total: 'mean' },
    ],
    rows,  // one clean, sorted point per day: day, active
  });

  // trend fits a least-squares line through the points; forecast: 8 carries it
  // eight steps past the last day as a dashed projection. It reads the grid's
  // filtered rows, so narrowing the grid refits the trend.
  createChart({
    grid,
    container: document.getElementById('chart'),
    type: 'line',
    x: 'day',
    y: 'active',
    legend: true,
    trend: { method: 'linear', forecast: 8 },
    title: 'The trend, projected ahead',
  });
</script>