I am trying to complete complex numbers in numpypy.
Progress is good, I picked up from previous work on the numpypy-complex2
branch.
Complex numbers come with extensive tests, it seems all the corner cases
are covered.
In porting the tests to numpypy, I came across a problem: numpy returns
different results than cmath.
Some of the differences are due to the fact that numpy does not raise a
ValueError for dividing by 0 or other silly input values,
but other differences are inexplicable (note the sign of the imaginary
part):
>>> numpy.arccos(complex(0.,-0.))
(1.5707963267948966-0j)
>>> cmath.acos(complex(0.,-0.))
(1.5707963267948966+0j)
>>>
or this one:
>>> cmath.acos(complex(float('inf'),2.3))
-infj
>>> numpy.arccos(complex(float('inf'),2.3))
(0.78539816339744828-inf*j)
Should I ignore the inconsistencies, or fix the 700 out of 2300 test
instance failures?
What should pypy's numpypy do - be consistent with numpy or with cmath?
cmath is easier and probably faster (no need to mangle results or input
args), so I would prefer cmath to trying to understand the logic behind
numpy.
Matti
2280c2365844
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