[boost] Re: Fixed Size Matrix

From: Larry Evans (cppljevans_at_[hidden])
Date: 2005-03-10 07:58:39

On 03/10/2005 01:31 AM, Erik Wien wrote:
[snip]
> 
> For what it's worth; If it turns out there is an interest in such a 
> class, I have already written one (with that exact declaration in fact) 
> I'd be more that willing to donate to boost. It can currently do 
> addition, subtraction and multiplication of matrices, as well as provide 
> functions for a lot of vector and matrix operations like generation of 
> rotation matrices, taking the length of a vector and so on and so forth.
> 
Isn't a matrix a "rank 2".  I'm using the term "rank" because that's an
apl term, and I'm a fan ;)  :

   http://www.aplusdev.org/APlusRefV2_4.html#17

Anyway, why not a template:

   template < typename T, typename Shape >
   class array
   {
   ...
   };

where Shape is a vector_c<unsigned, S1,S2,...,Sn>

to create a rank n array with S1 is length (or dimension)
of 1st axis, S2 the length of 2nd axis, ... ?  The strides
of such a "compile-time specified shape" array could also
be calculated at compile time as shown in the test_partial_product
function of fold_seq_test.cpp in fold_seq_test.zip in
http://boost-sandbox.sourceforge.net/vault/.