[Numpy-discussion] possible bug in concatenating character arrays

Faheem Mitha faheem at email.unc.edu
Sat Sep 4 18:46:07 CDT 2004


The following recipe gives a segmentation fault.

************************************************************************
In [1]: import numarray.strings as numstr

In [2]: foo = numstr.array("acgttatcgt", shape=(3,3))

In [3]: foo[0] + foo[1]
Segmentation fault
*************************************************************************

It works if instead one does:

*************************************************************************
In [4]: a = foo[0]

In [5]: b = foo[1]

In [6]: a
Out[6]: CharArray(['a', 'c', 'g'])

In [7]: b
Out[7]: CharArray(['t', 't', 'a'])

In [8]: a + b
Out[8]: CharArray(['at', 'ct', 'ga'])
***************************************************************************

In the case of numerical arrays, either method works.

In [9]: bar = numarray.array(range(9), shape=(3,3))

In [10]: bar
Out[10]:
array([[0, 1, 2],
       [3, 4, 5],
       [6, 7, 8]])

In [11]: a = bar[0]

In [12]: b = bar[1]

In [13]: a + b
Out[13]: array([3, 5, 7])

In [14]: bar[0] + bar[1]
Out[14]: array([3, 5, 7])

************************************************************

If this is a bug (I'd appreciate confirmation of this), should I
report to the bug tracking system? Please cc me, I'm not subscribed.

                                                         Faheem.





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