Re: [SL] rounding error

[Bernd P. <bp...@ch...>]

Hello Luke,

there are several "logical" ways to calculate discounts.

1) $ 2.95 x 0.1 = 0.295 -> round up to 0.3
   => ( 2.95 - 0.3 ) x 12 = 31.80

2) ($ 2.95 x 12) = 35.40
    => 35.40 - 3.54 = 31.86

Seems to me that SL is using calculation 1)
Of course rounding in 1) depends on the precision (which you changed
later on). You could argue that rounding should only be applied to the
final amount i.e. after calculating the line item total and in fact
some programs are doing this. 
Other people prefer a summary calculation as in 2)

In your particular case the easiest way might be to enter the price
manually and to put in a corresponding note explaining the calculation.

Bernd


On Mon, 07 Jan 2008 12:05:33 -0800
sql...@li... wrote:

> Hello
> 
> I have an invoice which appears to be calculating the discount 
> incorrectly.
> 
> The line item cost is $2.95 (sellprice--the list price is $2.99, and I 
> lowered this on the invoice to compensate for another seeming error).
> 
> Setting the discount to 10, with a quantity of 12, yealds a cost of 
> $31.80, while my calculater seems to think that it should equal $31.86.
> 
> SL 2.8.10; PGSQL 8.2.
> 
> Am I missing something obvious here?

-- 
プラゲ ベェアント - Bernd Plagge
ファースト・チョイス・インターネット(有)
First Choice Internet Ltd., Tokyo
Tel. 03-4500-7799
Fax. 03-4400-3723
mail: bp...@ch...
url: http://www.choicenet.ne.jp