Null<double> and arithmetics

[Vadim Ogranovich-3]

Hi,

Just want to make a suggestion. Currently
double x = Null<double>() * 0.01;
produces a valid double, which is confusing (I ran into it when I read
interest rates in %% and then converted to non-percent numbers).

I heard that there is a IEEE standard + libraries for things like NaN, Inf,
etc. It would be nice if  Null<numeric> conform to that standard.
Another option is to use Rmath library (a standalone byproduct of R-project)
which seems to handle NaN-s properly, but I don't have first-hand experience
with it.

Thanks, Vadim

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[Luigi Ballabio-4]

At 04:50 PM 5/5/02 -0500, Vadim Ogranovich wrote:
>Just want to make a suggestion. Currently
>double x = Null<double>() * 0.01;
>produces a valid double, which is confusing (I ran into it when I read
>interest rates in %% and then converted to non-percent numbers).
>
>I heard that there is a IEEE standard + libraries for things like NaN, Inf,
>etc. It would be nice if  Null<numeric> conform to that standard.

It would indeed.
Does anybody have any insight into this? Any URL?

Bye,
         Luigi

[Dirk Eddelbuettel]

> At 04:50 PM 5/5/02 -0500, Vadim Ogranovich wrote:
> >Just want to make a suggestion. Currently
> >double x = Null<double>() * 0.01;
> >produces a valid double, which is confusing (I ran into it when I read
> >interest rates in %% and then converted to non-percent numbers).
> >
> >I heard that there is a IEEE standard + libraries for things like NaN, Inf,
> >etc. It would be nice if  Null<numeric> conform to that standard.
>
> It would indeed.
> Does anybody have any insight into this? Any URL?

There is one, isn't it called IEEE 854 or something?  

I recall something authored a long time ago by a Berkeley ElecEng. prof.
A good google search might unearth that; else I check my old Octave
and R folders at home [ both packages deal with NaN ].

Dirk

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According to the latest figures, 43% of all signatures are totally worthless.  

[Dirk Eddelbuettel]

> > At 04:50 PM 5/5/02 -0500, Vadim Ogranovich wrote:
> > >I heard that there is a IEEE standard + libraries for things like NaN, Inf,
> > >etc. It would be nice if  Null<numeric> conform to that standard.
> >
> > It would indeed.
> > Does anybody have any insight into this? Any URL?
>
> There is one, isn't it called IEEE 854 or something?  
>
> I recall something authored a long time ago by a Berkeley ElecEng. prof.

It's IEEE 754, see  http://www.cs.berkeley.edu/~wkahan/

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According to the latest figures, 43% of all signatures are totally worthless.