Switch rounding mode

[J.Benoist Leger]

Hi

For doing interval analysis, I need some help :

if a is double scalar, b too, and I want to do :
> c= a*b

But in interval analisis I want to do :
> c.min = a \*/ b
> c.max = a /*\ b

where \*/ and /*\ are respectivly * where rounding mode is to -inf and inf.

I think I can do this :
> c=a*b;
> c.min=c-eps(c);
> c.max=c+eps(c);

But this is not the best way, my interval is to huge because
(c.max-c.min)=2*eps(c) and with the first way (c.max-c.min)=eps(c)

My question is, how I do the first way if it's possible ?

Thx,

-- 
J.Benoist Leger