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# 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.

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