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From: boost (boost_at_[hidden])
Date: 2001-04-24 08:38:02


Salut,

On Tuesday 24 April 2001 12:53, Dave wrote:

> > has (?) replaced char[]. (We only need to convince the performance
> > freaks that there is little or no cost involved.)
>
> Is that really possible? Surely one has to do 2-3 times as many
> floating-point ops to handle intervals as raw numbers. I know that in my
> application domain (simulation), nobody would be willing to pay that price.
> Typically these simulations use iterative methods that only strive for a
> few digits of accuracy before producing a result anyway.

Well, you can use better algorithms.
Suppose you want to calculate a zero of a function f(x).

You will need just one function call to check if x has a
zero in the interval -1..1:
if f( interval<double>(-1,1) ) contains no zero then it is proven that there
is no zero. Try to do this without interval arithmetics. Extending this
should be clear.

Best wishes,
Peter


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