@plotly/d3/src/arrays/quantile.js

A JavaScript visualization library for HTML and SVG.

// R-7 per <http://en.wikipedia.org/wiki/Quantile>
d3.quantile = function(values, p) {
  var H = (values.length - 1) * p + 1,
      h = Math.floor(H),
      v = +values[h - 1],
      e = H - h;
  return e ? v + e * (values[h] - v) : v;
};