Re: [Axiom-mail] Setting elements in a matrix

[Ralf Hemmecke]

On 02/29/2008 09:27 AM, Martin Rubey wrote:
> make SQMATCAT inherit from MATCAT.

I am sure you don't want that.

We have

MatrixCategory(R,Row,Col): Category == Definition where
  R   : Ring
  Row : FiniteLinearAggregate R
  Col : FiniteLinearAggregate R

  Definition ==> TwoDimensionalArrayCategory(R,Row,Col) with
     ...
     coerce: Col -> %
     transpose: Row -> %
     horizConcat: (%,%) -> %
     vertConcat: (%,%) -> %
     ...

There are even more functions that allow the result to be a non-square 
matrix.

SquareMatrix *should not* inherit from MatrixCategory!!!

The better way would be to factor out a subcategory that doesn't change 
the structure of the matrix and let SquareMatrix and MatrixCategory 
inherit from that.

Ralf