numpy.emath is a preferred alias for numpy.lib.scimath, available after numpy is imported.
Wrapper functions to more user-friendly calling of certain math functions whose output data-type is different than the input data-type in certain domains of the input.
For example, for functions like log() with branch cuts, the versions in this module provide the mathematically valid answers in the complex plane:
>>> import math >>> from numpy.lib import scimath >>> scimath.log(-math.exp(1)) == (1+1j*math.pi) True
Similarly, sqrt(), other base logarithms, power() and trig functions are correctly handled. See their respective docstrings for specific examples.