Re: ublas : double * matrix

From: jhrwalter (walter_at_[hidden])
Date: 2002-01-18 17:48:16

--- In boost_at_y..., Peter Schmitteckert (boost) <boost_at_s...> wrote:
> Salut,
> 
> On Thursday 17 January 2002 15:35, Toon Knapen wrote:
> 
> > theoretically scalar-matrix multiplication is commutative and 
thus a * M
> > == M * a.
> 
> BTW, is one allowed to use "non-commutative" scalars for ublas,
> or is it implied that "a * b == b * a" ?

To get usual linear algebra functionality, one should assume that the 
scalars form the approximation of a field. But I currently do not see 
any obvious reason, why one couldn't try to use a noncommutative 
multiplication for scalars. But then the approximations of vector 
space laws and linear operator properties may not hold.

Regards

Joerg