numpy.signbit

numpy.signbit(x, /, out=None, *, where=True, casting='same_kind', order='K', dtype=None, subok=True[, signature, extobj]) = <ufunc 'signbit'>

Returns element-wise True where signbit is set (less than zero).

Parameters:

Parameters:	`x : array_like` The input value(s). `out : ndarray, None, or tuple of ndarray and None, optional` A location into which the result is stored. If provided, it must have a shape that the inputs broadcast to. If not provided or `None`, a freshly-allocated array is returned. A tuple (possible only as a keyword argument) must have length equal to the number of outputs. `where : array_like, optional` Values of True indicate to calculate the ufunc at that position, values of False indicate to leave the value in the output alone. **kwargs For other keyword-only arguments, see the ufunc docs.
Returns:	`result : ndarray of bool` Output array, or reference to `out` if that was supplied. This is a scalar if `x` is a scalar.

x : array_like: The input value(s).
out : ndarray, None, or tuple of ndarray and None, optional: A location into which the result is stored. If provided, it must have a shape that the inputs broadcast to. If not provided or None, a freshly-allocated array is returned. A tuple (possible only as a keyword argument) must have length equal to the number of outputs.
where : array_like, optional: Values of True indicate to calculate the ufunc at that position, values of False indicate to leave the value in the output alone.
**kwargs: For other keyword-only arguments, see the ufunc docs.

Returns:

result : ndarray of bool: Output array, or reference to out if that was supplied. This is a scalar if x is a scalar.

>>> np.signbit(-1.2)
True
>>> np.signbit(np.array([1, -2.3, 2.1]))
array([False,  True, False])