Re: [xsl] Rounding errors in financial app transforms

["Dimitre Novatchev" <dnovatchev@xxxxxxxxx>]

> BTW. Actually I asked you about BCD in an off-list message but you didn't say
> anything about it then.

This is what you get when talking about too many things in the same message,

Rule 1: Split different topics in different messages if you want that
they all receive (equal) attention.

As for performing numerical processing with XSLT, FXSL has done it
since at least 5 years ago: exponential and logarithmic functions,
trigonometric and hyper-trigonometric functions, finding the root of
any continuous function on R, numerical differentiation, numerical
integration ..., etc...

And nobody has complained about precision -- seems as if Pi with 13
correct digits after the decimal point is OK.

But, of course, financial calculations have other kind of users...

Probably I should think about implementing some symbolic evaluation --
then nobody can raise rounding problems.


--
Cheers,
Dimitre Novatchev
---------------------------------------
Truly great madness cannot be achieved without significant intelligence.
---------------------------------------
To invent, you need a good imagination and a pile of junk
-------------------------------------
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, Justin Johansson <procode@xxxxxxxxxx> wrote:
> Hi Michael & Dimitre,
>
> Dimitre:
> >You seem to be un-aware of xs:decimal.
>
> Correct, and was just considering further after posting, that my original apps
> were developed with XSLT 1.0 and perhaps I just got into the mode of thinking
> that the problem still remained without considering the introduction of
> xs:decimal
> in 2.0.
>
> BTW. Actually I asked you about BCD in an off-list message but you didn't say
> anything about it then.
>
>
> Michael:
> >If you use a schema-aware transformation, with a schema that defines the
> >relevant input fields as xs:decimal, then this will tend to happen
> >automatically. If you use a non-schema-aware transformation, or if the input
> >contains data that isn't validated or isn't validated as xs:decimal, then
> >you can achieve the same effect "by hand", for example by writing
> >sum(product/sales-value/xs:decimal(.))
>
> Great, that has to be another big plus for a schema-aware processor.  It opens
> up new application domains for XSLT.
>
> I know that I'm pushing the application of XSLT probably way beyond the
> initial design domain(s) for the language, but it really is the next best
> thing
> to sliced bread, so that's why I've been attempting to use it real anger.
>
> >Be aware that there can be a performance hit in using xs:decimal compared to
> >xs:double, it shouldn't be done unless you actually need it.
>
> Naturally.
>
>
> Anyway, all, since I've inadvertently overlooked xs:decimal, no doubt others
> have also and so this has to be another selling point for XSLT (2.0), even
> if not schema-aware by use of Michael's sum()  solution.
>
> Thanks to you both.  Time for a re-read of the spec :-)
>
> Justin Johansson
>
> *** A horse with no name is called Lambda ***