From: Eleanor McHugh <eleanor@...>
Date: 2008-07-02T22:12:40+09:00
Subject: Re: Arithmetic oddity

On 2 Jul 2008, at 13:48, Minh Tran wrote:
> It still look odd as the value in s[2] is 2.0 which doesn't seems to
> have any rounding problem.
>
> In any case is there any workaround to fix get the condition as true ?

Floating point representations are in many cases (such as irrational  
numbers like square root of 2) only approximations to a given value,  
you therefore have to test that the value is accurate to a given  
precision (number of significant digits). For example, given:

	x = (1.0 + 1.0) ** 0.5

you could write your test as:

	(x ** 2.0).between?(1.9999, 2.0001)


Ellie

Eleanor McHugh
Games With Brains
http://slides.games-with-brains.net
----
raise ArgumentError unless @reality.responds_to? :reason