code: def signbit(x, out=None, where=None, **kwargs):
      """
      Returns element-wise True where signbit is set (less than zero).
  
      Parameters
      ----------
      x : array_like
          The input value(s).
      out : Tensor, None, or tuple of Tensor 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 tensor 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
  
      Returns
      -------
      result : Tensor of bool
          Output tensor, or reference to `out` if that was supplied.
  
      Examples
      --------
      >>> import mars.tensor as mt
  
      >>> mt.signbit(-1.2).execute()
      True
      >>> mt.signbit(mt.array([1, -2.3, 2.1])).execute()
      array([False,  True, False])
      """
      op = TensorSignbit(**kwargs)
      return op(x, out=out, where=where)
  
file_path: mars/mars/tensor/arithmetic/signbit.py
imports: import numpy
  from ...None import opcodes
  from ..utils import inject_dtype
  from .core import TensorUnaryOp
  from .utils import arithmetic_operand
label_desc: Use image node_id 1 for calling a global function with example usage: signbit(x, out, where) and returns: op