# Re: Natural keys vs Aritficial Keys

From: toby <toby_at_telegraphics.com.au>
Date: Sat, 23 May 2009 00:36:11 -0700 (PDT)

On May 22, 11:28 pm, paul c <toledobythe..._at_oohay.ac> wrote:
> toby wrote:
> > On May 22, 9:10 pm, paul c <toledobythe..._at_oohay.ac> wrote:
> >>> paul c wrote:
> >>>>> paul c wrote:
> >> ...
> >>>>>> Oh, just remembered another one - fixed-point decimal arithmetic!
> >>>>> What do you need that for?
> >>>> To get the same answer as the lawyer with his amortization tables.
> >>> Integers are integers no matter the base.
> >> Sure they are, but I was talking about decimal points.  Eg., it bugs me
> >> that the most widely-used (that doesn't mean most popular) cpu
> >> 'architecture', Intel's, can't express the fraction 2/5 exactly.

```>

> > If expressing exact rationals is what you want, then that is trivially

> > done using integer arithmetic - as is fixed point decimal. Hardware
```
> > decimals, which essentially died with the VAX, don't help you express
> > rationals.
```>

> > Have a play with these:
```
> >http://gmplib.org/(see mpq for rationals)
> >http://docs.sympy.org/
```>
```

> ....
```>
```

> The point has nothing to do with rationals, some decimal fractions are
> irrational.

Your point keeps changing. First you mentioned "fixed point decimals", which being finite, most certainly are rational. Then you implied that ordinary rational numbers aren't easily representable with current processors (they are). Now you're saying you want the ability to represent irrational numbers in hardware? Well you can do that as well; symbolically.

```> I never said a cpu should express exact values, rather it
```

> should express the exact same values people who are accustomed to
> decimal arithmetic or traditional slide-rules come up wiith.

Just decide what you want, and you can have it.

> To talk
> otherwise is to argue for Betamax.

Straw man? Received on Sat May 23 2009 - 09:36:11 CEST

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