Haskell Matrix Library...

Benjamin Franksen benjamin.franksen at bessy.de
Sun Jun 26 14:44:52 EDT 2005

On Sunday 26 June 2005 19:22, Henning Thielemann wrote:
> The reason why these operators are methods of classes 
> is that it shall be possible to write mathematical expressions which
> can be universally used for different types of numbers, such as
> Float, Double, Rational, Integer and so on. Prelude's class framework
> is oriented at the scalar types it provides. My concern is: Are
> matrices a natural extension of these scalar types? What is
> (fromInteger 1) for the matrix class? The identity matrix or the
> matrix which consists entirely of ones?

The identity matrix, of course. 

For a given dimension, numeric literals of value x should be converted 
as (x .* m_id), where (.*) is scalar multiplication, and m_id is the 
identity matrix. This is BTW an embedding of the number field into the 
(quadratic) matrices (over teh numbers in question) as a subring.

The real problem is the dimension, which we would like to have as an 
extra type argument and this is incompatible with the Prelude.


More information about the Libraries mailing list