Re: [boost] different matrix library?

Subject: Re: [boost] different matrix library?
From: joel (joel.falcou_at_[hidden])
Date: 2009-08-15 02:28:18

Edward Grace wrote:
> Err - surely the point of overloading is to assign meaningful context 
> specific behaviour to the same operator, so.
>
>  unsigned a,b,c; c = a ^ b; // ^ => XOR makes sense.
>
>  pseudovector<3> c;
>  vector<3> a,b;  c = a ^ b;     // ^ => Wedge product makes sense XOR 
> does not.
>
Well, except there is use case in computer vision or machien learning in 
which you have large matrix of integer on which you apply bitwise 
operation before feeding to some solver. ^ is clearly 'elementwise xor' 
in this context.

so wedge_product is a better alternative.
> If, for example, b and c were pseudovectors then s would be a (true) 
> scalar and could be assigned to the concrete type double.  This is 
> where carrying along some (meta) information concerning the 
> transformation rules of these different entities would be both tricky 
> and crucial.
In NT2 matrix of size(1,1) are castable to scalar and such operations 
works flawlessly.

________________________________________
Joel Falcou - Assistant Professor
PARALL Team - LRI - Universite Paris Sud XI
Tel : [phone]