Re: [pure-lang-users] math.pure

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

On Wed, 2008-08-20 at 17:32 -0400, John Cowan wrote:
> Eddie Rucker scripsit:
> > Should we have the following rules?
> > _+:nan = nan;
> > nan+:_ = nan;
> > nan<:_ = nan;
> > _<:nan = nan;
> > 
> > My thinking is that if any part of a complex number is nan then the
> > whole thing is not a number. OTOH, inf+:inf, 0+:inf, inf+:0, etc, you
> > might want to keep that way for either further processing or to let the
> > user know the result is a complex number. What does everyone think about
> > this?
> 
> I'd avoid this: it's easy enough to add a post-processing ruleset
> to make the change.  Just because the real side of a computation has
> lost significance doesn't mean the imaginary side doesn't still contain
> useful data (or vice versa).  The whole point of inf and nan is to allow
> computation to continue, postponing the check for significance to the end.
> 

Thanks John! You and Albert keep it coming.

e.r.