Proposal for modifying gnucash to use exact quantities

Richard Wackerbarth
Tue, 25 Jul 2000 18:59:57 -0500

On Tue, 25 Jul 2000, John Hasler wrote:
> Richard Wackerbarth writes:
> > Actually, price is a rational and quantity is an integer.  (At least in
> > the pumps that I helped program)
> I'm not talking about gasoline anymore, but about prices and quantities in
> general.  Treating price and quantity as reals (always rationals or
> integers in practice) allows for whatever wonky deal buyer and seller see
> fit to make for whatever bizarre materials they choose to deal in.

I think that this is a mistake. Although, mathematically, reals are a 
superset of the rationals and those are, in turn, are a superset of the 
integers, I think it is a mistake to allow the arbitrary extension of the 
domains. In practice, accounting always restricts the allowable values.

> Thus you were counting strokes, not gasoline.
Precisely. We sold gasoline by the pump stroke although we quoted the price 
in dollars per gallon.

> Yes.  Some things come in distinguishable packages.  Others don't.
I don't think that the accountants view it that way.

> > And I can be reasonably sure that I would not receive either 19 or 21
> > "747"s when I pay for exactly 20.
> In other words, if your count and the vendor's count differ by too much you
> will dispute the bill.  How much is too much depends on the product.

> At the end of the day, you agree to pay an _exact_ amount of money for
> whatever the vendor piles up on your loading dock.  This amount may or may
> not correspond exactly to quoted_price * quantity_received.
Agreed, as long as it is "close".

> The amount of stuff your vendor records as having left his inventory
> heading in your direction may differ slightly from the amount you tell your
> inventory system you received and neither of you will necessarily get bent
> out of shape. 
That's right.

> The same cannot be said of the amount of money he asks you
> to pay him and the amount you actually pay.
No, the same CAN be said. Rather than argue about a dollar or two, the vendor 
may elect to accept a little less than the "ask" amount.
What we will have difficulty justifying is that I report paying one amount 
and he reports receiving a different amount. Neither of those amounts 
necesarily match the contract amount.

Funny. The government is better at counting pennies than it is at counting 
ounces of gold. :-).