als-statistics/lib/utils/round.js

Modular JS statistics toolkit for Node.js and the browser: descriptive stats, correlations (Pearson/Spearman/Kendall), t-tests & ANOVA (Student/Welch), reliability (Cronbach’s alpha), regression (linear/logistic), clustering (DBSCAN/HDBSCAN), and table/co

export default function round(d, max = 8) {
  if (d === 0) return 0;
  if (d == null) return 0;
  const dd = Number(d);
  if (!Number.isFinite(dd)) return 0; // или dd, по договорённости
  const rounded = Math.trunc(dd);
  if (dd === rounded) return dd;
  let frac = Math.abs(dd - rounded), n = 0;
  while (frac && frac < 1 && n < max) { frac *= 10; n++; }
//   return Number(dd.toFixed(n));
  return dd.toFixed(n);
}