Re: [office-formula] DB question

[Andreas J Guelzow <aguelzow@math.concordia.ab.ca>]

On Wed, 2009-12-23 at 08:04 -0500, Patrick Durusau wrote:

> On the DB function, what is the purpose of the various formulas for 
> other aspects of depreciation?

I am not sure which "formulas for other aspects of depreciation" you are
referring to. The first formula describes how "rate" is calculated.
"rate" is used in the following formulae. The next 3 formulae together
give a recursive definition of "value" (iniital "value", "value"
progression during lifetime, "value" for period following lifetime.)

The last two formulae finally describe how DB is calculated from
"value". Of course this could all be combined into a single large
formula involving some large summations (and some encoding for the
required rounding of the "rate"), but I think the current presentation
is much more understandable (and verifiable).
> 
> Are these normative or simply instructive for the curious or bored?

Clearly these formulae are meant to be normative. In fact we should have
similar formulae for all other financial functions. It is such formulas
which truly define what these functions ought to return.

Andreas

> 

-- 
Andreas J. Guelzow
Concordia University College of Alberta