From: bug@...
Date: 2008-02-10T05:19:58+09:00
Subject: Re: Internal Rate of Return (#156)

On Feb 8, 4:43 pm, Siep Korteling <s.kortel...@gmail.com> wrote:
> James Gray wrote:
> > by Harrison Reiser
> (...)
> >This week's quiz is to calculate the IRR for any given variable-length
> >list of numbers, which represent yearly cash flows,
>
> In real life, it's not yearly. IIR needs a time dimension.
>
> irr([-100, a_date],[+30,another_date],[+35,yet_a _date])
>
> James, I learned a LOT thanks to you.
>
> regards,
>
> Siep
>
> --
> Posted viahttp://www.ruby-forum.com/.

I was hoping someone would try this!  It wouldn't be very difficult to
adapt an existing yearly algorithm to do it; all that changes is the
exponent for each term.  I'd take only two arguments, though: the
starting date and {dates => cash flows}.

Harrison Reiser