Re: division by zero in intnum

[idmiddle@umich.edu]

Yes, I had noticed that.  Intnum seems to avoid rational divide-by-zero 
errors, but not floating-point ones.


On Wed, 19 Aug 2009, Kurt Foster wrote:

> Hmmm, look what happened when I specified the left endpoint a bit differently 
> -- I simply replaced the t_REAL 0.5 with the t_FRAC 1/2, which is exact.:
>
> ? intnum(r=[1/2,-1/2], 1, 1/sqrt(4*r^2-1))
> time = 6 ms.
> %1 = 0.65847894846240835431252317365398422201
>
> Perhaps that will say something about the nature of the problem.
>
> Hope that helps!
>
>
> On Aug 19, 2009, at 2:20 PM, idmiddle@umich.edu wrote:
>
> > I've been having trouble with intnum, and managed to distill it down to the 
> > following, which occurs in both 2.3.4 and the latest svn:
> >
> > ? intnum(r=[0.5,-1/2], 1, 1/sqrt(4*r^2-1))
> > ***   at top-level: intnum(r=[0.5,-1/2],1,1/sqrt(4*r^2-1))
> > ***                                        ^---------------
> > *** _/_: division by zero
> >
> > (It makes no difference whether the order of the singularity is specified 
> > or not.)
> >
> > Ivan