Re: Negative zeros?

[Vic Norton]

At 10:06 PM -0400 9/12/05, John W. Eaton wrote:
> For more info, take a look at the section on signed zeros in the paper
> What Every Computer Scientist Should Know About Floating-Point
> Arithmetic (google the title and you will find it on the web).

At 6:05 AM +0200 9/13/05, David Bateman wrote:
> Maybe you should do a google search for the article "Much ado about 
> zeros sign bit" and read about the importance of having two 
> representations of zero.

At 9:18 AM +0200 9/13/05, Stefan van der Walt wrote:
> The article John referred to is available at
>
> http://eins2002.info.uni-karlsruhe.de/literatur/goldberg-floating-point.pdf
>
> The other one that David referred to was written by William Kahan
> (sometimes called father of floating-point mathematics, being the
> primary architect of the IEEE standard), but isn't available for free
> on the web.  Here is a complete reference:
>
> "Branch Cuts for Complex Elementary Functions, or Much Ado About
> Nothing's Sign Bit" by William Kahan in "The State of the Art in
> Numerical Analysis", (eds. Iserles and Powell), Clarendon Press,
> Oxford, 1987.
>
> However, he has many other interesting writings pertaining to
> Floating-Point on his webpage at
>
> http://www.cs.berkeley.edu/~wkahan/
>
> (like "Matlab's Loss is Nobody's Gain" and "How Java's Floating-Point
> hurts Everyone Everywhere").

I am sorry, John, David, and Stephan. I am a mathematician. I don't 
choose to read nonsense. Zero is zero is zero.

I realize that e-1000000 is positive and -e-1000000 is negative and 
that these might be represented by 0 and -0 respectively on a 
machine. But I will never accept that
   0 * (-1) = -0.

Regards,

Vic

--
*---* mailto:address@hidden
|     Victor Thane Norton, Jr.
|     Mathematician and Motorcyclist
|     Bowling Green, Ohio
*---* http://vic.norton.name



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