[Numpy-discussion] Problem with concatenate and object arrays

Travis Oliphant oliphant.travis at ieee.org
Tue Sep 5 12:05:00 CDT 2006

Matthew Brett wrote:
> Hi,
>> This is a result of PyArray_FromAny changing when object arrays are
>> explicitly requested (which they are in this case --- although behind
>> the scenes).
> Hmm - I think I am hitting a related bug/feature/surprising change in
> behavior, which is showing up rather obscurely in a failure of the
> scipy.io matlab loading tests:
> http://projects.scipy.org/scipy/scipy/ticket/258
> Here's the change I wasn't expecting, present with current SVN:
> a = arange(2)
> b = arange(1)
> c = array([a, b], dtype=object)
> c
> ->
> array([[0, 1],
>        [0, 0]], dtype=object)
> On a previous version of numpy (1.02b.dev2975) I get the answer I was expecting:
> array([[0], [0 1]], dtype=object)

This should now be fixed.  The code was inappropriately not checking for 
dimensions when object arrays were being constructed.  Now, it raises 
the appropriate error and then interprets it correctly using the extra 
object creation code.  

Users of scipy 0.5.1 will only have to upgrade NumPy to get the fix (the 
SciPy install won't have to be re-built).


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