demo D279

A trend line and a forecast in React

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 React version. The grid mounts through the createLatticeGrid adapter, which takes its configuration as ordinary props and hands back the live grid through a ref. The grid below is the same one every other tab runs.

The configuration

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

<div id="app"></div>

<script type="module">
  import React from 'https://esm.sh/react@18';
  import { createRoot } from 'https://esm.sh/react-dom@18/client';
  import { createGrid } from 'https://cdn.jsdelivr.net/npm/@toclocoinc/lattice-grid@1.71.0/lattice-grid.esm.min.js';
  import { createLatticeReact } from 'https://cdn.jsdelivr.net/npm/@toclocoinc/lattice-grid@1.71.0/modules/react.esm.min.js';
  import { createChart } from 'https://cdn.jsdelivr.net/npm/@toclocoinc/lattice-grid@1.71.0/modules/charts.esm.min.js';

  const { LatticeGrid, LatticeChart } = createLatticeReact({ React, createGrid, createChart });

  const columns = [
      { field: 'day', title: 'Day', type: 'number' },
      { field: 'active', title: 'Active users', type: 'number', total: 'mean' },
  ];

  const rows = [/* one clean, sorted point per day: day, active */];

  function App() {
    const [grid, setGrid] = React.useState(null);

    // 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.
    return (
      <>
        {grid && (
          <LatticeChart
            grid={grid} type="line" x="day" y="active" legend
            trend={{ method: 'linear', forecast: 8 }}
            title="The trend, projected ahead"
            style={{ height: '300px' }}
          />
        )}
        <LatticeGrid rowKey="id" columns={columns} rows={rows} onGridReady={setGrid} style={{ height: '320px', marginTop: '14px' }} />
      </>
    );
  }

  createRoot(document.getElementById('app')).render(<App />);
</script>