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

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

On Fri, 2008-08-22 at 00:50 +0200, Albert Graef wrote:
> Eddie Rucker wrote:
> > I've been in faculty meetings all day today
> 
> Oh dear, that sucks. This silly ritual called "meetings" must have been 
> invented long ago by non-creative people to terrorize the rest of us, or 
> to pretend that they are actually doing something. ;-)

LOL. I agree completely! The only other thing I might add, It's the
administrator's way of making us pay for summers and holidays ;-)

> You surely mean inf^x=inf unless x<0 in which case inf^x=0.0. These 
> should all work now, also the -inf cases, except that C pow() insists on 
> setting 1.0^x = 1.0 no matter what x is. Also, x^0.0 will always be 1.0. 
> I guess that's POSIX behavior, so it should be ok.

What a moron :-O I'm totally embarrassed? Oh shame shame. If I reached
up right now, I would be too short to touch bottom.

> Not sure about the complex cases x^(+/-inf) where x<0, but I think that 
> these will always return nan+:nan right now. I'm open to suggestions 
> there. For finite, non-integral y, (-inf)^y gives inf+:inf or 0+:0, 
> depending on whether y>0 or y<0, which looks good to me.

Still mortified over that last one but mzscheme gives the following:
For x < 0,
  > (expt -4.0 -inf.0)
  0.0
  > (expt -4.0 +inf.0)
  +inf.0

For complex x,
  > (expt 1+2i -inf.0)
  +nan.0+nan.0i
  > (expt 1+2i +inf.0)
  +nan.0+nan.0i

e.r.