Re: 0.3-0.2=0.999999999998?

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#16375

From: Roedy Green
Date: Thu, 04 Mar 1999 00:00

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On Thu, 04 Mar 1999 23:57:30 +1100, Tudor Holton
<tudor@alphalink.com.au> wrote:

>I've never understood why we can't just represent numbers after the
>decimal place as the size in reverse.  e.g. 16.16 would be A:3D  (or
>16:61 in decimal)

Mike Cowlishaw (The inventor of Rexx and NetRexx) would agree with
you.  He has been lobbying for floating point hardware to be
redesigned to work in base 10 rather than base 2 to avoid these
anomalies.  People are used to .3333... + .66666 = .9999 but they
don't expect 0.1 to behave the same way.

I disagree.  Binary arithmetic is faster and simpler.  The repeaters
just move to different places.  You can't get rid of them.  If you
want absolute precision, use scaled integer arithmetic which is many
times faster that floating point (e.g. integer pennies for currency,
with a decorative decimal point inserted for display).

For the JAVA GLOSSARY and the CMP Utilities: <http://mindprod.com>
--
Roedy Green,  Canadian Mind Products 
-30-

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From: roedy@mindprod.com (Roedy Green)
Subject: Re: 0.3-0.2=0.999999999998?
Date: 1999/03/04
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