[REBOL] Re: financial functions
From: gchiu:compkarori at: 18-Apr-2002 12:31
On Wed, 17 Apr 2002 13:27:59 -0400
"[chalz--earthlink--net]" <[chalz--earthlink--net]> wrote:
> Heh! Perhaps if I had some idea as to what internal
> rate of return meant, I could give you a hand ;)
I found this definition "The internal rate of return is the
interest rate that makes the present value of the
investment's income stream -- its costs and payoffs -- add
up to 0. "
which is an economics lecture about the value.
> Perhaps the difference between your function and
> Excel's function is a matter of rounding? Since I see no
> decimals in your comparative values, and they are so
> close, it almost seems to suggest that you rounded up,
> where Excel rounded down No?
I think the maths is okay, but I'm sure the way I'm doing it
is not at all economical. As far as I can tell, you have to
approximate to solve for the irr, and keep approximating
till you reach 0.