Re: [xsl] Rounding errors in financial app transforms

["Dimitre Novatchev" <dnovatchev@xxxxxxxxx>]

> So if you try to round $100.105 to 2 decimal places you will get $100.11
> whereas any financial system will (probably) expect $100.10.
>
> If this IS the case you are going to have to force values at the tipping
> point to go down not up.

Isn't this exactly what
      round-half-to-even($arg as numeric?, $precision as xs:integer)
as numeric?
is supposed to do?

  http://www.w3.org/TR/xpath-functions/#func-round-half-to-even




--
Cheers,
Dimitre Novatchev
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Truly great madness cannot be achieved without significant intelligence.
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To invent, you need a good imagination and a pile of junk
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You've achieved success in your field when you don't know whether what
you're doing is work or play





On 7/26/07, W Charlton <XSLList@xxxxxxxxxx> wrote:
> Justin,
>
> It may be relevant to be aware that rounding in financial transactions is
> not a simple mathematical problem, there is rounding and there is rounding.
>
> Financial systems (at least all the ones we have dealt with) use have a
> specific way or rounding money known as "bankers rounding" or "half even
> rounding".
>
> The problem value is the n.5. Most mathematics based system (and most
> humans) including both versions of XSLT round to n+1.
>
> Bankers however round to n-1. That way I presume they get to make more
> money!!
>
> So if you try to round $100.105 to 2 decimal places you will get $100.11
> whereas any financial system will (probably) expect $100.10.
>
> If this IS the case you are going to have to force values at the tipping
> point to go down not up.
>
> Does that shed some light on your problem?
>
>
> William Charlton
> The yMonda team
> yMonda Limited
> w: www.ymonda.net