tonmcg

let 
    Table.CreateAmortization = let 
        AmortizationFunction = (initialAmount as number, interestRate as number, numberOfPeriods as number, periodicity as text, optional date as any, optional balloonPayment as number) as table =>
        let
            CompoundingMap = {{"Daily",365}, {"Monthly",12}, {"Quarterly",4}, {"Semi-annual",2}, {"Annual",1}},
            CompoundingPeriod = List.First(List.Select(CompoundingMap, each _{0} = periodicity)){1},
            Balloon = if balloonPayment is null then 0 else balloonPayment,
            PeriodicInterest = interestRate / CompoundingPeriod,
            TotalPeriods = numberOfPeriods * CompoundingPeriod,
            Annuity = initialAmount * ((PeriodicInterest) * Number.Power(1 + (PeriodicInterest), TotalPeriods)) / (Number.Power(1 + (PeriodicInterest), TotalPeriods) - 1) - Balloon * (-PeriodicInterest) / ((1 + PeriodicInterest) - (Number.Power(1 + PeriodicInterest, TotalPeriods + 1))),