From: Oliver Schad <spam.entfernen.und.bring.gefaelligst.ein.bier.mit@...>
Date: 2010-11-26T02:25:15+09:00
Subject: Re: Ruby 1.8 vs 1.9

Phillip Gawlowski wrote:

> I'm quite aware that IEEE 754 defines the result of x_0/0 as infinity.

The point is that you can't guarantee that you has a 0 with floiting 
point aithmetics. Every value you have to read as "as close as possible 
to the meant value for this machine and this number size".

The machines are not perfect they can't work mathematical correct in 
many situations.

And you have to deal with this situation - all people doing numeric 
things know that. Doing numeric calculations with a computer means to 
calculate something as near as possible in the given environment and 
requirements.

So in this sense is dividing a number through zero in real computers 
dividing something which is close to the number, which I mean through 
something which is close to zero.

And in fact it's not a bad idea to define if you have something which is 
very close to zero (because you don't know if it's exactly zero), you 
should treat it as very close to zero and not zero itself.

In a perfect world with perfect computers which has infinite registers, 
infinite storage and infinite fast CPUs computers would know that zero 
is equal to zero. But in this world computer knows only that zero is 
close to zero.

Regards
Oli

-- 
Man darf ruhig intelligent sein, man muss sich nur zu helfen wissen