demo D216

Heatmap in Angular

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 Angular version. A standalone component takes the whole configuration through one config input, surfaces grid events as outputs, and exposes the live grid on a getter for anything the inputs do not cover.

The configuration

import { Component, ViewChild } from '@angular/core';
import { bootstrapApplication } from '@angular/platform-browser';
import { createGrid } from '@toclocoinc/lattice-grid';
import '@toclocoinc/lattice-grid/css';
import { createChart } from '@toclocoinc/lattice-grid/modules/charts';
import { LatticeGridComponent, provideLattice } from '@toclocoinc/lattice-grid/angular';

const 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' },
];

const rows = [/* circuit records */];



@Component({
  selector: 'app-root',
  standalone: true,
  imports: [LatticeGridComponent],
  template:
    '<div id="chart" style="height:340px"></div>' +
    '<lattice-grid [config]="grid" (grid-ready)="onGridReady()" style="display:block;height:320px;margin-top:14px"></lattice-grid>',
})
export class AppComponent {
  @ViewChild(LatticeGridComponent) gridRef!: LatticeGridComponent;

  grid = {
    rowKey: 'id',
    columns: columns,
    rows: rows,
  };

  // The grid is created once the view has rendered, so the live instance
  // arrives on grid-ready rather than in ngAfterViewInit.
  onGridReady() {
    const grid = this.gridRef.grid;
    // region across, status down, charge at every crossing. diverging colours
    // the cells from a midpoint out. The chart reads the live grid through the
    // ref, so a filter redraws it.
    createChart({ grid, container: '#chart', type: 'heatmap', x: 'region', series: 'status',
      y: 'charge', diverging: true, title: 'Charge by region and status' });
  }
}

bootstrapApplication(AppComponent, {
  providers: [provideLattice({ createGrid })],
});