[Numpy-discussion] bug in numpy.ndarray?

[Warren Weckesser]

On Sun, May 8, 2011 at 7:23 PM, Charles R Harris
<charlesr.harris at gmail.com>wrote:

>
>
> On Sun, May 8, 2011 at 3:15 PM, Paul Anton Letnes <
> paul.anton.letnes at gmail.com> wrote:
>
>> Hi,
>>
>> it seems that I have found a bug in numpy.ndarray. numpy 1.5.1, python
>> 2.7.1 from macports on mac os x 10.6.7. I got the same error on Fedora 14
>> with numpy 1.4.1 and python 2.7. Appending a [0] to the last line solves the
>> problem.
>>
>> % python testcrash.py
>>
>>          [14:13:27 on 11-05-08]
>> <type 'numpy.ndarray'> [ 12.+0.1j]
>> <type 'numpy.ndarray'> [ 1.+0.1j]
>> complex128
>> Traceback (most recent call last):
>>  File "testcrash.py", line 11, in <module>
>>    A[0] = A[0] + (eps1 - eps2)
>> TypeError: can't convert complex to float
>>
>>  % cat testcrash.py
>> #!/usr/bin/env python
>>
>> import numpy
>>
>> A = numpy.zeros(10, dtype=numpy.complex128)
>> eps1 = numpy.complex128([12.0 + 0.1j])
>> eps2 = numpy.complex128([1.0 + 0.1j])
>>
>
> It's the brackets, numpy.complex128([1.0 + 0.1j]) is a 1d array, not a
> scalar. The error message is less than helpful though.
>
>

But the same pattern works fine with float64:

In [2]: x = array([1.0, 2.0])

In [3]: y = array([10.0])

In [4]: x[0] = y   # Works

In [5]: a = array([1.0, 2.0], dtype=complex128)

In [6]: b = array([10.0 + 1j])

In [7]: a[0] = b   # Error
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)

/Users/warren/<ipython console> in <module>()

TypeError: can't convert complex to float


Something is fishy about that.

Warren



> <snip>
>
> Chuck
>
>
> _______________________________________________
> NumPy-Discussion mailing list
> NumPy-Discussion at scipy.org
> http://mail.scipy.org/mailman/listinfo/numpy-discussion
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/numpy-discussion/attachments/20110508/e5384e54/attachment.html>