From: "John W. Kennedy" <jwkenne@...>
Date: 2004-05-13T04:58:53+09:00
Subject: Re: Major Addition Bug?

Sean O'Dell wrote:
> Funny though, if I set a variable to 1547.91 exactly, it is represented just 
> fine.

No it isn't.

ruby -e "puts sprintf('%20.13f', 1547.91)"

> I had to massage my floating point math in C/C++ a lot many years ago, but I 
> always assumed it was a flaw in the MS compiler, 

Kindly get in touch with your C/C++ teacher and shoot him.  What we are 
talking about here is a basic characteristic of nearly all computers 
made since the mid-1960's, and a large fraction of the computers made 
before then.

Only a handful of languages support exact decimal arithmetic (COBOL, 
PL/I, Ada, Java, and REXX come to mind), and IBM zSeries and iSeries 
mainframes are about the only modern machines capable of doing decimal 
arithmetic in hardware.

-- 
John W. Kennedy
"Compact is becoming contract,
Man only earns and pays."
   -- Charles Williams.  "Bors to Elayne:  On the King's Coins"