[SciPy-user] Mathematica Element-wise Multiplication
Alan G Isaac
aisaac@american....
Mon Dec 17 07:04:01 CST 2007
On Sun, 16 Dec 2007, Johann Cohen-Tanugi apparently wrote:
> Assuming that this natural linear algebra could be
> retrieved when, and only when, the array is 1D
You appear to be talking about a "natural" linear algebra
for 2D objects. For example, when textbooks talk of row
vectors and column vectors, they are talking about 2D
objects, even though they use a simplified indexing. (This
vocabulary is only slightly misleading: after all, matrices
of a given dimension are also vectors and can be indexed
with a single index---Matlab allows this (column major) and
NumPy allows this too (row major, via the `flat`
attribute).)
If that is what you always seek, stick with matrices::
>>> x=numpy.mat([0,1,2])
>>> x
matrix([[0, 1, 2]])
>>> x.T
matrix([[0],
[1],
[2]])
>>>
In the meantime, you can always add an axis if you wish::
>>> x
array([0, 1, 2])
>>> y=x[:,None]
>>> y
array([[0],
[1],
[2]])
hth,
Alan Isaac
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