Heatmap Density

import DataSet from '@antv/data-set';
import { Chart } from '@antv/g2';

const chart = new Chart({
  container: 'container',
  autoFit: true,
});

chart.options({
  type: 'view',
  data: {
    type: 'fetch',
    value: 'https://assets.antv.antgroup.com/g2/diamond.json',
  },
  scale: {
    x: { nice: true, domainMin: -0.5 },
    y: { nice: true, domainMin: -2000 },
    color: { nice: true },
  },
  children: [
    {
      type: 'heatmap',
      data: {
        transform: [
          {
            type: 'custom',
            callback: (data) => {
              const dv = new DataSet.View().source(data);
              dv.transform({
                type: 'kernel-smooth.density',
                fields: ['carat', 'price'],
                as: ['carat', 'price', 'density'],
              });
              return dv.rows;
            },
          },
        ],
      },
      encode: { x: 'carat', y: 'price', color: 'density' },
      style: {
        opacity: 0.3,
        gradient: [
          [0, 'white'],
          [0.2, 'blue'],
          [0.4, 'cyan'],
          [0.6, 'lime'],
          [0.8, 'yellow'],
          [0.9, 'red'],
        ],
      },
    },
    { type: 'point', encode: { x: 'carat', y: 'price' } },
  ],
});

chart.render();