[Numpy-discussion] Matrix Class [was numpy release]

[Bill Spotz]

On Apr 28, 2008, at 10:15 PM, Alan G Isaac wrote:

> On Mon, 28 Apr 2008, Bill Spotz apparently wrote:
>> http://www.scipy.org/ConjugateGradientExample ... provides
>> one small area where the vector classes would be useful.
>
> Maybe not.
> I posted an alternate version of your algorithm,
> just below yours,
> sticking very close to your example.

Alan,

Nice.

To quote: "The second version of the algorithm provided above suggests  
that little if anything was gained by the use of matrices."

If matrix multiplication in my example is replaced with np.dot() in  
yours, then when IS anything gained by using matrices?

As for this example, my version should work with a properly  
implemented sparse_matrix A, but the array approach precludes that.   
That is to say, I could convert A to a matrix if it is provided as an  
array, but you could not convert a sparse_matrix to an array.

** Bill Spotz                                              **
** Sandia National Laboratories  Voice: (505)845-0170      **
** P.O. Box 5800                 Fax:   (505)284-0154      **
** Albuquerque, NM 87185-0370    Email: wfspotz@sandia.gov **