[boost] Re: lazy exact arithmetic

From: David Abrahams (dave_at_[hidden])
Date: 2005-02-22 09:58:56

"Brandon Kohn" <bkohn_at_[hidden]> writes:

> Hello,
>
> I was just posting to see if there is any interest in developing a library 
> to help with exact arithmetic using the lazy arithmetic strategy?

I don't think I can devote any time to the actual development, but I'm
very interested in the outcome.

> I've been working for the last couple of years with computational geometry 
> algorithms, and have found that such a library is really essential to 
> overcoming problems due to floating point precision/round off errors in most 
> computational geometry algorithms with non-brute force complexity. The idea 
> behind the lazy paradigm is that exact computation (using rational 
> arithmetic with arbitrary sized integers) is too costly to be used all the 
> time. So the exact computations are delayed until such a time as you cannot 
> reliably make decisions with the information you have from the 'lazy' 
> filters. The lazy filters are implemented as a layer of calculation that 
> uses interval arithmetic to compare numerical quantities. 

Great; are you aware of
http://www.boost.org/libs/numeric/interval/doc/interval.htm
??

Could you use that as a substrate?

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com