Финансисты тут есть?

[dil]

Кто может рассказать, как работает встроенная екселевская (или oocalc'овская) функция PMT()?
В смысле, развернуть ее в понятные формулы.


PMT
Returns the periodic payment for an annuity with constant interest rates.

Syntax
PMT(Rate; NPER; PV; FV; Type)
Rate: the periodic interest rate.
NPER: the number of periods in which annuity is paid.
PV: the present value (cash value) in a sequence of payments.
FV (optional): the desired value (future value) to be reached at the end of the periodic payments.
Type (optional): the due date for the periodic payments. Type=1 is payment at the beginning and Type=0 is payment at the end of each period.
In the OpenOffice.org Calc functions, parameters marked as "optional" can be left out only when no parameter follows. For example, in a function with four parameters, where the last two parameters are marked as "optional", you can leave out parameter 4 or parameters 3 and 4, but you cannot leave out parameter 3 alone.

Example
What are the periodic payments at a yearly interest rate of 1.99% if the payment time is 3 years and the cash value is 25,000 currency units. There are 36 months as 36 payment periods, and the interest rate per payment period is 1.99%/12.
PMT(1.99%/12;36;25000) = -715.96 currency units. The periodic monthly payment is therefore 715.96 currency units.

Вот как из 36 месяцев, 1.99% и 25000 получить эти 715.96?