[Numpy-tickets] [NumPy] #301: power with negative argument returns 0
NumPy
numpy-tickets at scipy.net
Sat Sep 30 17:18:36 CDT 2006
#301: power with negative argument returns 0
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Reporter: stefan | Owner: somebody
Type: defect | Status: new
Priority: normal | Milestone: 1.0 Release
Component: numpy.core | Version:
Severity: normal | Keywords:
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The power function returns an (incorrect) value for negative powers of
integers:
{{{
In [1]: N.power(3,-2)
Out[1]: 0
}}}
Unlike integer division, which is well defined, I am not sure what the
behaviour of power should be. Tim Hochberg's comment on the topic can be
seen on the mailing list thread at
http://thread.gmane.org/gmane.comp.python.numeric.general/8418/focus=8418
In short, it offers the possibility of making numpy.power behave like
Python's math.pow, which always returns floats, whereas x**y will be
equivalent to the Python ** integer behaviour.
--
Ticket URL: <http://projects.scipy.org/scipy/numpy/ticket/301>
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