fnAnnuity function

dynamic fnAnnuity(
  1. dynamic v1,
  2. dynamic v2
)

Annuity(rate, periods): present-value annuity factor per period (capital recovery factor)

Implementation

dynamic fnAnnuity(dynamic v1, dynamic v2) {
  final rate = varToDouble(v1);
  final n = varToInt(v2);
  if (rate == 0) return n == 0 ? 0.0 : 1.0 / n;
  return rate / (1 - pow(1 + rate, -n));
}