Re: Negative zeros?

[Paul Kienzle]

How about:

  function disp_abs_zero(a), a(a==0)=0; builtin('disp',a); end
  dispatch('disp','disp_abs_zero',typeinfo([1,1]))
  dispatch('disp','disp_abs_zero',typeinfo(1))

Now:

  octave> disp([0 0 0]*-1)
    0  0  0

Sorry, but there is no convenient way to dispatch on the print function 
defined for the type.

- Paul

On Sep 13, 2005, at 8:15 PM, Vic Norton wrote:

> OK, so there isn't easy way. So I'll just have Perl strip all the 
> minus signs from my -0.0's.
>
> Regards,
>
> Vic
>
> At 10:06 PM -0400 9/12/05, John W. Eaton wrote:
> > On 12-Sep-2005, Vic Norton wrote:
> >
> > | Look at the following code
> > |     octave> CS = [ 0 0 0 ]
> > |     CS =
> > |
> > |       0  0  0
> > |
> > |     octave> CS *= -1
> > |     CS =
> > |
> > |       -0  -0  -0
> > |
> > | I find this a real annoyance. To paraphrase Gertrude Stein:
> > |     A zero is a zero is a zero.
> > | Is there some easy way to stop Octave from outputting negative 
> > zeros?
> >
> > No.
> >
> > Does it matter?  -0 == 0.  But I think it is useful to keep the sign.
> > It is also what other languages do (Octave is not doing anything
> > tricky to give -0 results), and there is some logic to it.  It is also
> > the IEEE standard behavior for floating point arithmetic.
> >
> > 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).
> >
> > jwe
>
>
> --
> *---* mailto:address@hidden
> |     Victor Thane Norton, Jr.
> |     Mathematician and Motorcyclist
> |     Bowling Green, Ohio
> *---* http://vic.norton.name
>
>
>
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