[GiNaC-devel] multiplying a matrix with 0 makes it become a scalar 0

[Richard B. Kreckel]

Hi!

Jens Vollinga wrote:
>> What about making matrix a stand alone type (as opposed to being subclass
>> of basic)? The code dealing with matrices is very different from
>> everything else anyway.
> 
> Mmmh, have to think about that. It looks like a good idea. But I am not 
> sure about the implications, yet. In case we do this, the matrix stuff 
> probably looks like an incomplete copy of one of the many existing LA 
> packages. Maybe it can be removed completely then and replaced by some 
> interface code to an existing LA package?

I don't know of any existing LA package that works well in the symbolic 
domain. As a matter of fact, the rules of the game turn out to be quite 
different from the numeric domain, in terms of complexity. You wouldn't 
want to bother about Bareiss elimination and such things when 
considering only numbers. (This is one of the traps about symbolic 
computation, people keep running into. Cf. the IMHO bad textbook by 
Steeb and Shi.)

OTOH, I don't really oversee the pros and cons of making matrix a 
standalone type. It could enhance things, or it could make things more 
cumbersome. One would have to give it a try and see how things work out.

Cheers
   -richy.
-- 
Richard B. Kreckel
<http://www.ginac.de/~kreckel/>