COBie export: sizes, areas and durations

A value rounded to three decimals (or another count) for the workbook.

round(x, d) = Math.round(x × 10ᵈ) ÷ 10ᵈ

The value is multiplied by a power of ten in 64-bit before it is rounded, so a decimal half can fall just below the half: round(0.5005, 3) gives 0.5, because 0.5005 × 1000 is 500.49999999999994.

const round = (x, d = 3) => Math.round(x * 10 ** d) / 10 ** d;

Floor elevation and height, room height and room areas as the workbook holds them.

length = round(x × k, 3); area = round(x × k², 3)

k is 1 when the file's unit is one of the five named units, otherwise the millimeters per file unit. The value kept in the workbook is rounded to three decimals of that unit. Areas use k × k.

const num = (x, d = 3) => (Number.isFinite(x) ? round(x * facts.k, d) : null);   // file units → the Facility's unit
const area = (x) => (Number.isFinite(x) ? round(x * facts.k * facts.k, 3) : null);

The height of each floor, from its elevation to the next floor's.

height = elevationₙ₊₁ − elevationₙ

One 64-bit subtraction of two elevations read from the file, in file units, after the floors are sorted by elevation. The top floor has no height.

floors.forEach((f, i) => { const nx = floors[i + 1]; f.height = nx && Number.isFinite(nx.elevation) && Number.isFinite(f.elevation) ? nx.elevation - f.elevation : null; });

The length of a warranty from its start and end dates.

years = (end − start) ÷ (365.25 × 86400000 ms), rounded to 0.1

Both dates are parsed as UTC days, so the difference is a whole number of days. The result is rounded to one decimal of a year and is null when it is not above zero.

// ---------------------------------------------------------------- out
const yearsBetween = (a, b) => { if (!isDay(a) || !isDay(b)) return null; const y = (Date.parse(b) - Date.parse(a)) / (365.25 * 86400000); return y > 0 ? Math.round(y * 10) / 10 : null; };

A type's expected life in years, from a value in years, months, weeks or days.

years = months ÷ 12, weeks ÷ 52.1775, days ÷ 365.25; rounded to 0.1

The cell must be a plain decimal number. The result is rounded to one decimal of a year and kept only when it is above 0 and at most 200.

const lifeOf = (v, unit) => {
  const s = blank(v);
  if (!s || !/^\d+(\.\d+)?$/.test(s)) return '';
  const u = String(unit || '').toLowerCase(), x = Number(s);
  const y = /month/.test(u) ? x / 12 : /week/.test(u) ? x / 52.1775 : /day/.test(u) ? x / 365.25 : x;
  return y > 0 && y <= 200 ? String(Math.round(y * 10) / 10) : '';
};

The day a warranty ends, when the workbook gives only its start and its length in years.

end = start + round(years × 12) months

The duration is turned into a whole number of months with Math.round and added to the start date with setUTCMonth. A start day the end month does not have rolls over into the following month, as JavaScript dates do.

const wy = Number(blank(t.warrantydurationparts));
if (got.warrantyStart && wy > 0 && /year/i.test(t.warrantydurationunit || 'year')) { const d = new Date(got.warrantyStart + 'T00:00:00Z'); d.setUTCMonth(d.getUTCMonth() + Math.round(wy * 12)); got.warrantyEnd = d.toISOString().slice(0, 10); }