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Re: Best way to represent fractional values?

• To: "Chiusano Joseph" <chiusano_joseph@b...>
• Subject: Re: Best way to represent fractional values?
• From: "Hugh Wallis" <hugh_wallis@h...>
• Date: Mon, 10 Feb 2003 14:27:47 -0500
• Cc: <xml-dev@l...>
• References: <008c01c2d12c$80f4ac80$c2941bac@h...> <3E47E909.2A3ACC71@b...> <00f101c2d130$1589e830$c2941bac@h...> <3E47F4C7.7F6FFA0B@b...> <014a01c2d137$3254a610$c2941bac@h...> <3E47F99D.52414C5D@b...>

Thanks - it is my preference too although other problems arise in my
application if I introduce a complex type here (all other values are
derivable from anySimpleType - so the string representation would still fit
that mould) - I was wondering if there was a "best practice". Actually I
would also prevent a zero value for denominator in a complete
implementation.

Because of some the use cases I have to deal with I might even need to allow
floats for numerator and denominator - you know - 1/3E23 - I started with
integers but got push back!!

Cheers

Hugh
----- Original Message -----
From: "Chiusano Joseph" <chiusano_joseph@b...>
To: "Hugh Wallis" <hugh_wallis@h...>
Cc: <xml-dev@l...>
Sent: Monday, 10 February, 2003 2:12 PM
Subject: Re:  Best way to represent fractional values?


Ah yes - sorry for the cornfusion.

They I would say stick with one of the 2 proposals in your original
e-mail - I personally prefer (1), because it nicely separates the
numerator and denominator - although you may want to change the
datatypes of the "numerator" and "denominator" elements to be integer.

Joe Chiusano
Booz | Allen | Hamilton

Hugh Wallis wrote:
>
> But my point is that I can never make fractionDigits large enough to reach
a
> representation of 1/3 since that would require fractionDigits to equal
> infinity. I want to be able to represent exactly 1/3, not some close
> approximation of it.
>
> Now I know people are going to say "you can't do that in computers because
> of floating point stuff" but that isn't really true - if you represent the
> numerator and denominator separately then you can represent it perfectly
> fine.
>
> A use-case for this is the representation of a tax calculation where the
> legislation specifically dictates factors to be applied to other numbers
> that are fractions (and often more complicated than 1/3 which I was using
as
> a simple example). These factors may well not be representable accurately
as
> decimals.
>
> Cheers
>
> Hugh
> ----- Original Message -----
> From: "Chiusano Joseph" <chiusano_joseph@b...>
> To: "Hugh Wallis" <hugh_wallis@h...>
> Cc: <xml-dev@l...>
> Sent: Monday, 10 February, 2003 1:51 PM
> Subject: Re:  Best way to represent fractional values?
>
> <Snip>
> What you suggest would limit me to 0.33
> </Snip>
>
> Not at all, if you make fractionDigits greater than 2.
>
> Hugh Wallis wrote:
> >
> > Thanks Joe - but I don't think that solves the problem. How do you
> represent
> > the value 1/3 exactly this way? What you suggest would limit me to 0.33
> > which is 33/100 which does not equal 1/3
> >
> > Hugh
> > ----- Original Message -----
> > From: "Chiusano Joseph" <chiusano_joseph@b...>
> > To: "Hugh Wallis" <hugh_wallis@h...>
> > Cc: <xml-dev@l...>
> > Sent: Monday, 10 February, 2003 1:01 PM
> > Subject: Re:  Best way to represent fractional values?
> >
> > Hugh,
> >
> > W3C Schema does define facets for these:
> >
> > totalDigits - max # of digits in the value
> > fractionDigits - max # of digits in fractional part
> >
> > Ex. from W3C Schema Primer [1]:
> >
> > <simpleType name='amount'>
> >   <restriction base='decimal'>
> >     <totalDigits value='8'/>
> >     <fractionDigits value='2' fixed='true'/>
> >   </restriction>
> > </simpleType>
> >
> > Hope that helps,
> > Joe Chiusano
> > Booz | Allen | Hamilton
> >
> > [1] http://www.w3.org/TR/xmlschema-0/
>
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• References:
  • Best way to represent fractional values?
    • From: "Hugh Wallis" <hugh_wallis@h...>
  • Re: Best way to represent fractional values?
    • From: "Chiusano Joseph" <chiusano_joseph@b...>
  • Re: Best way to represent fractional values?
    • From: "Hugh Wallis" <hugh_wallis@h...>
  • Re: Best way to represent fractional values?
    • From: "Chiusano Joseph" <chiusano_joseph@b...>
  • Re: Best way to represent fractional values?
    • From: "Hugh Wallis" <hugh_wallis@h...>
  • Re: Best way to represent fractional values?
    • From: "Chiusano Joseph" <chiusano_joseph@b...>

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