numpy.sign(x, /, out=None, *, where=True, casting='same_kind', order='K', dtype=None, subok=True[, signature, extobj]) = <ufunc 'sign'>
Returns an elementwise indication of the sign of a number.
The sign
function returns 1 if x < 0, 0 if x==0, 1 if x > 0
. nan is returned for nan inputs.
For complex inputs, the sign
function returns sign(x.real) + 0j if x.real != 0 else sign(x.imag) + 0j
.
complex(nan, 0) is returned for complex nan inputs.
Parameters: 


Returns: 

There is more than one definition of sign in common use for complex numbers. The definition used here is equivalent to which is different from a common alternative, .
>>> np.sign([5., 4.5]) array([1., 1.]) >>> np.sign(0) 0 >>> np.sign(52j) (1+0j)
© 2005–2019 NumPy Developers
Licensed under the 3clause BSD License.
https://docs.scipy.org/doc/numpy1.17.0/reference/generated/numpy.sign.html