Horizontal Violin in JavaScript

// Build a Gaussian density profile + raw observations for a group.
// The sample template seeds Math.random, so this renders identically across reloads.
function gaussianViolin(mean, sd, n) {
  var density = []
  for (var v = mean - 3 * sd; v <= mean + 3 * sd; v += sd / 6) {
    var z = (v - mean) / sd
    density.push([Math.round(v * 10) / 10, Math.exp(-0.5 * z * z)])
  }
  var points = []
  for (var k = 0; k < n; k++) {
    // Box–Muller transform on two uniform samples
    var u1 = Math.random(),
      u2 = Math.random()
    var g = Math.sqrt(-2 * Math.log(u1)) * Math.cos(2 * Math.PI * u2)
    points.push(mean + g * sd)
  }
  return { density: density, points: points }
}

var options = {
  series: [
    {
      name: 'Latency',
      data: [
        { x: 'Auth', y: gaussianViolin(120, 18, 400) },
        { x: 'Search', y: gaussianViolin(210, 35, 500) },
        { x: 'Checkout', y: gaussianViolin(160, 22, 350) },
        { x: 'Recommend', y: gaussianViolin(260, 45, 300) },
      ],
    },
  ],
  chart: {
    type: 'violin',
    height: 460,
  },
  title: {
    text: 'Response time distribution by service (ms)',
  },
  plotOptions: {
    bar: {
      horizontal: true,
      distributed: true,
    },
    violin: {
      normalize: 'group',
      // dots in a darker shade of each violin's colour, no outline (strokeWidth: 0)
      points: { show: true, size: 3, jitter: 0.9, strokeWidth: 0 },
    },
  },
  colors: ['#14b8a6', '#3B82F6', '#f59e0b', '#ef4444'],
  stroke: { width: 1, colors: ['#888'] },
  legend: { show: false },
  xaxis: {
    title: { text: 'Response time (ms)' },
  },
}

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