Re: [pure-lang-users] Yet another quirk with MinGW

[Eddie R. <er...@bm...>]

On Wed, 2008-08-20 at 11:34 -0400, John Cowan wrote:
> Eddie Rucker scripsit:
> 
> > (1) Is sqrt supposed to be defined for nan and inf? ln, sin, cos, etc,
> > are.
> 
> The hardware says that sqrt(inf) is inf and sqrt(nan) is nan, which
> is what you expect given that inf*inf = inf and nan*nan = nan.

Yep! But they aren't defined in math.pure. 
sqrt inf => sqrt inf and sqrt nan => sqrt nan.

> In IEEE floats, the less tampering with the hardware the better.

Most of the time I'd agree, but I still think log 0 => -inf sucks big
time. Even though the limit of log x -> -inf as x -> 0 that is very
different from saying log 0 == -inf. That's like saying 9/0 = inf
because lim 9/x -> inf as x -> 0.

>         There was a young fellow of Trinity
>         Who solved the square root of infinity,
>             But while counting the digits
>             Was seized by the fidgets
>         Dropped maths and took up divinity.
> 
> No wonder!

Floating point is a bugger.

e.r.