Re: [boost] formal review request : mcs::units

From: Matthias Troyer (troyer_at_[hidden])
Date: 2007-02-09 16:36:05

On 9 Feb 2007, at 12:31, Andreas Harnack wrote:

> james.jones_at_[hidden] wrote:
>
>> I suspect this idea, while clever, does not cover the problem  
>> domain sufficiently well to be superior to lists.
>
> Please have a look at the attached list.
> (I hope sending attachments  works.)
>
> This is a list of all SI units I could find on a quick search. The  
> first two columns are nominator and denominator a corresponding  
> rational number would have. Of course, this is not a proof, but the  
> numbers suggest that for practical purposes we're not even getting  
> near a range that's likely to be dangerous.
>
> By the way, there's no need to worry about growing intermediate  
> results: a/b * c/d is equal to a/d * c/b and these two factors can  
> be normalized before the multiplication is carried out. If that's  
> done and a/b and c/d were in normal form, then so will be the  
> result and there's no intermediate result growing larger then the  
> final product.
>
> Andreas

Have you thought about negative powers, e.g. number densities (m^-3)

Matthias