[Numpy-discussion] Detect subclass of ndarray
Alan G Isaac
aisaac@american....
Sat Mar 24 15:06:04 CDT 2007
On Sat, 24 Mar 2007, Travis Oliphant apparently wrote:
> My opinion is that a 1-d array in matrix-multiplication
> should always be interpreted as a row vector. Is this not
> what is currently done? If not, then it is a bug in my
> mind.
>>> N.__version__
'1.0'
>>> I
matrix([[ 1., 0.],
[ 0., 1.]])
>>> I*N.ones(2)
matrix([[ 1., 1.]])
If N.ones(2) were treated as a row vector,
matrix multiplication is not possible.
So the question is what should happen.
I would like an exception raised.
The current behavior is lmost certainly not desirable,
although it has the virute of matching ``dot``.
>>> N.dot(I,N.ones(2))
matrix([[ 1., 1.]])
Cheers,
Alan Isaac
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