[Numpy-discussion] [IPython-dev] Discussion with Guido van Rossum and (hopefully) core python-dev on scientific Python and Python3
Tue Feb 14 17:12:55 CST 2012
On Tue, Feb 14, 2012 at 9:16 AM, Dag Sverre Seljebotn
> It was about the need for a dedicated matrix multiplication operator.
has anyone proposed that? I do think we've had a proposal on the table
for generally more operators: i.e. like matlab's ".*" vs "*", and yes,
matrix multiplication would be one use of that feature.
> (The difference from the current
> situation being that people avoid np.matrix because it's so similar to
> np.ndarray that you too easily get confused).
I'm not sure that's why -- I think it's because:
a) np.matrix is really not quite finished - it's not full featured
enough to be truly useful (maybe that's the same as you "similar to
b) all it provides is syntax candy for matrix operations -- and how
much of our code is matricx operations? a couple lines our of hundreds
(that was always the case with my MATLAB code, and it even the more so
now -- I can count my uses of np.dot on one hand...)
> I myself never missed a matrix multiplication operator, precisely
> because my matrices are very often diagonal or triangular or sparse or
> something else, so having syntax candy simply to invoke np.dot wouldn't
> help me.
exactly -- so that could address point (a), but I still think in most
code it's only going to amke a small fraction of teh code more
PS: the notable exception is instructional code involving matrix
arithmetic -- it would be nice there, and that is where I've seen the
strongest requests for it.
Christopher Barker, Ph.D.
Emergency Response Division
NOAA/NOS/OR&R (206) 526-6959 voice
7600 Sand Point Way NE (206) 526-6329 fax
Seattle, WA 98115 (206) 526-6317 main reception
More information about the NumPy-Discussion