[Numpy-discussion] Obscure code in concatenate code path?

Daπid davidmenhur@gmail....
Thu Sep 13 11:57:32 CDT 2012


On Thu, Sep 13, 2012 at 6:39 PM, Warren Weckesser
<warren.weckesser@enthought.com> wrote:
> I would expect an error, consistent with the behavior when 1 < axis < 32.

In that case, you are hitting the dimension limit.

np.concatenate((a,b), axis=31)
ValueError: bad axis1 argument to swapaxes

Where axis=32, axis=3500, axis=None all return the flattened array.


I have been trying with other functions and got something interesting.
With the same a, b as before:


np.sum((a,b), axis=0)
ValueError: operands could not be broadcast together with shapes (2) (3)

np.sum((a,b), axis=1)
array([[ 0.  0.], [ 2.  2.  2.]], dtype=object)

np.sum((a,b), axis=2)
ValueError: axis(=2) out of bounds

This is to be expected, but now this is not consistent:

np.sum((a,b), axis=32)
ValueError: operands could not be broadcast together with shapes (2) (3)

np.sum((a,b), axis=500)
ValueError: axis(=500) out of bounds


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