On 28 April 2010 14:30, Alan G Isaac aisaac@american.edu wrote:

On 4/28/2010 12:08 PM, Dag Sverre Seljebotn wrote:

it would be good to deprecate the matrix class from NumPy

Please let us not have this discussion all over again.

I think you may be too late on this, but it's worth a try.

The matrix class is very useful for teaching. In economics for example, the use of matrix algebra is widespread, while algebra with arrays that are not matrices is very rare. I can (and do) use NumPy matrices even in undergraduate courses.

If you do not like them, do not use them.

This is the problem: lots of people start using numpy and think "hmm, I want to store two-dimensional data so I'll use a matrix", and have no idea that "matrix" means anything different from "two-dimensional array". It was this that inspired David's original post, and it's this that we're trying to find a solution for.

If you want `matrix` replaced with a better matrix object, offer a replacement for community consideration.

Thank you, Alan Isaac

PS There is one change I would not mind: let A * M be undefined if A is an ndarray and M is a NumPy matrix.

I can definitely vote for this, in the interest of catching as many inadvertent matrix users as possible.

Anne