[Numpy-discussion] ANN: NumPy 1.2.0

Pauli Virtanen pav@iki...
Mon Sep 29 05:28:28 CDT 2008


Mon, 29 Sep 2008 12:07:53 +0200, Matthieu Brucher wrote:

>>>>> np.log(-1 + 0j)
>> 3.1415926535897931j
>>>>> np.log(-1 - 1e-99j)
>> -3.1415926535897931j
>>>>> np.log(-1 + 1e-99j)
>> 3.1415926535897931j
>>
>> I'd guess this is typically harmless, but may lead to problems if your
>> code relies on the choice of branch at the branch cut.
>>
>> Could you check if this is really the case? If log seems to work OK,
>> then it's a problem with the test and not the functions.
> 
> The result is what you expected.

Do you mean that the problem is with the test, or with the branch cut of 
log?

-- 
Pauli Virtanen



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