Re: [boost] [PQS] rank of a physical quantity?

From: Janek Kozicki (janek_listy_at_[hidden])
Date: 2006-06-17 19:23:24

Gerhard Wesp said:     (by the date of Thu, 15 Jun 2006 11:39:15 +0200)

> On Thu, Jun 15, 2006 at 02:17:38PM +0700, Oleg Abrosimov wrote:
> > the problem here is that PQS deals with only dimensions, but physical 
> > quantities have not only that, they have rank also.
> 
> What is the rank of a physical quantity?

good question indeed. I can grasp the idea of that. In fact above quote
written by Oleg was a revelation for me. But how to include the concept
or "rank" into the library design? Would it boil down to
abstract_quantity_id, but with different name?

I'm really not sure if one can hold energy inside a vector (say: vector
field of energy), perhaps some physicist here can answer this question.
But I'm sure that momentum can be hold as a vector (ie. momentum vector).

Could it possibly mean, that some quantities can be represented as
vectors, while representing others as vector doesn't make sense - would
it be "rank" then?

But anyway - even if we find a specification on how to implement it, I'd
rather focus on it later. There is already tons of work with this
library.

-- 
Janek Kozicki                                                         |