[Numpy-discussion] strange behavior of numpy.unique

Phillip Feldman phillip.m.feldman@gmail....
Tue Nov 6 20:27:21 CST 2012


numpy.unique behaves as I would expect for small inputs like the following:

In [12]: x= [0, 0, 1, 0, 1, 2, 0, 1, 2, 3]

In [13]: unique(x, return_index=True)
Out[13]: (array([0, 1, 2, 3]), array([0, 2, 5, 9], dtype=int64))

But, when I give it something larger, the return index values do not always
correspond to the first occurrences in the input. The documentation is
silent on the question of how the return index values are chosen when a
given element of x appears more than once. Either the documentation should
be
clarified, or better yet, the behavior should be changed.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mail.scipy.org/pipermail/numpy-discussion/attachments/20121106/36065c47/attachment.html 


More information about the NumPy-Discussion mailing list