From: Dan North <dan@...>
Date: 2003-08-19T23:33:49+09:00
Subject: Re: NaN and Inifinity

Hi Scott.

It might help to think of NaN meaning "some undefined value". Then it 
makes sense that you can't assign it - it's undefined - and also that 
you can't compare two NaNs - they're both undefined so how can you? All 
you can do is use Float.nan? to ask whether the result of what you just 
did, in this case log(-1), is undefined. It also helps explain why it 
isn't, um, defined in Math or Float.

Cheers,
Dan

 Scott Thompson wrote:

> If I do something like
>
> a = Math::log(-1)
>
> then a properly takes the value NaN.
>
> Is there any way to explicitly assign the variable "a" to NaN (or 
> Inifinity or -Infinity) to begin with?  I tried finding "NaN" as a 
> constant but couldn't locate it.  It doesn't appear to be a constant 
> in Float or Math.
>
> Scott
>
>
>