Re: NAN and INF

[Marty Kraimer <mrk@aps.anl.gov>]

OK,

I will use this.
I am not sure isinf should be true for a NAN but it looks like this is the best 
we can do.

Thanks,

Marty

Rarback, Harvey wrote:

> 	Marty,
>
>
> > Brian McAllister wrote:
> >
> >
> > > > > > On 4/11/2002 at 8:54:36 PDT, Rarback, Harvey wrote:
> > >  >> For VMS I could define epicsMath.h as
> > >  >>
> > >  >> #ifndef epicsMathh #define epicsMathh
> > >  >>
> > >  >> #include <math.h> #define isinf(D) 0
> > >  >>
> > >  >> #endif /* epicsMathh */
> > >  >>
> > >  >> Any better ideas for implementing isinf on VMS?
> > >
> > >  > Sounds ok to me.  BTW, the same should apply to Tru64 Unix, aka Digital
> > >  > Unix, aka OSF-1.
> > >
> > > Digital Unix provides isnan()/isnanf() and finite()/finitef() for doubles
> > > and floats, respectively.  In libm, defined in math.h.
> > >
> > > finite() looks just like isinf().
> > >
> > > ----
> > > Brian McAllister                    Controls Programmer/Beam Physicist
> > > mcallister@mit.edu                        MIT-Bates Linear Accelerator
> > > (617) 253-9537                                           Middleton, MA
> > Sorry but I still don't know what I should do.
> >
> > For alpha and for vms I currently have
> >
> > #ifndef epicsMathh
> > #define epicsMathh
> >
> > #include <math.h>
> > #define isinf(D) 0
> >
> > #endif /* epicsMathh */
> >
> >
> > Are you suggesting?
> >
> > ifndef epicsMathh
> > #define epicsMathh
> >
> > #include <math.h>
> > #define isinf(D) (!finite((D)))
> >
> > #endif /* epicsMathh */
> >
> > Please dont' respont without testing because I have no way to test on alpha or
> > vms.
>
> I tested the routines defined in math.h on
>
> DEC C V5.9-005 on Digital UNIX V4.0 (Rev. 1229) and
> Compaq C V6.2-003 on OpenVMS Alpha V7.3
>
> and not surprisingly got the same results for the isnan and !finite routines:
>
> a = 0.0   isnan(a) = 0  isinf(a) = 0
> b = NaNQ  isnan(b) = 1  isinf(b) = 1
> c = INF   isnan(c) = 0  isinf(c) = 1
>
>                                    --Harvey