Re: Ada routine to compute Internal Rate Of Return

[Marin David Condic <condicma@bogon.pwfl.com>]

Tom Moran wrote:
> 
> Do you have a polynomial zero finder about?
> As for speed, for realistic projects you can probably make a pretty
> good initial guess, and for the real world your coefficients are such
> guesses that it's not worth computing to much accuracy.
> (And NPV is a better indicator than IRR anyway.)

No I do not have a polynomial zero finder. Got one of those lying around
on the workbench somewhere? Probably right next to stud finder if your
workbench is well organized.

Speed is not usually much of a concern for this sort of thing since you
typically only need to calculate it once for a given set of
wild-ass-guesses about future cash flows. However, one wouldn't want to
be grotesque about it either - just on principal if not because of
unknown future uses.

Yes, yes, yes, yes. NPV is a better indicator. But there are a lot of
senior bozos who have gotten used to IRR and want to see that number
too. It can be kind of handy in capital budgeting decisions. And yes,
IRR can be both misleading and misinterpreted, but you kind of have to
spit it out anyway - so I need a routine to do it. I'm also aware that
the precision of a computed IRR far exceeds the precision of the
rectally-extracted numbers on which it is based. But as an exercise in
Computer Science, we could have some fun computing it to the precision
of a Long_Long_Float, couldn't we?

And while I'm out begging for someone to solve my problems for me, how
about a routine to compute Modified Internal Rate Of Return? ;-)

MDC
-- 
Marin David Condic
Real Time & Embedded Systems, Propulsion Systems Analysis
United Technologies, Pratt & Whitney, Large Military Engines
M/S 731-95, P.O.B. 109600, West Palm Beach, FL, 33410-9600
Ph: 561.796.8997         Fx: 561.796.4669
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