This is documentation for an old release of NumPy (version 1.17). Read this page Search for this page in the documentation of the latest stable release (version 2.2).

Mathematical functions with automatic domain (numpy.emath)

Note

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.