Basic Heatmap in JavaScript

// Seeded PRNG so the heatmap is identical on every load (stable snapshots).
var __seed = 0x11a2c3d4
function rand() {
  __seed |= 0
  __seed = (__seed + 0x6d2b79f5) | 0
  var t = Math.imul(__seed ^ (__seed >>> 15), 1 | __seed)
  t = (t + Math.imul(t ^ (t >>> 7), 61 | t)) ^ t
  return ((t ^ (t >>> 14)) >>> 0) / 4294967296
}

function generateData(count, yrange) {
  var i = 0
  var series = []
  while (i < count) {
    var x = 'w' + (i + 1).toString()
    var y = Math.floor(rand() * (yrange.max - yrange.min + 1)) + yrange.min

    series.push({
      x: x,
      y: y,
    })
    i++
  }
  return series
}

var options = {
  series: [
    {
      name: 'Dashboard',
      data: generateData(18, {
        min: 0,
        max: 90,
      }),
    },
    {
      name: 'Reports',
      data: generateData(18, {
        min: 0,
        max: 90,
      }),
    },
    {
      name: 'Search',
      data: generateData(18, {
        min: 0,
        max: 90,
      }),
    },
    {
      name: 'Profile',
      data: generateData(18, {
        min: 0,
        max: 90,
      }),
    },
    {
      name: 'Billing',
      data: generateData(18, {
        min: 0,
        max: 90,
      }),
    },
    {
      name: 'Settings',
      data: generateData(18, {
        min: 0,
        max: 90,
      }),
    },
    {
      name: 'Inbox',
      data: generateData(18, {
        min: 0,
        max: 90,
      }),
    },
    {
      name: 'Calendar',
      data: generateData(18, {
        min: 0,
        max: 90,
      }),
    },
    {
      name: 'Files',
      data: generateData(18, {
        min: 0,
        max: 90,
      }),
    },
  ],
  chart: {
    height: 350,
    type: 'heatmap',
  },
  dataLabels: {
    enabled: false,
  },
  colors: ['#008FFB'],
  title: {
    text: 'Feature Usage by Week (single color)',
  },
}

var chart = new ApexCharts(document.querySelector('#chart'), options)
chart.render()