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