code: def sigmoid(x, out=None):
      """
      Logistic sigmoid function.
  
      Parameters
      ----------
      x : numpy array
          Input data.
      out : numpy array, optional
          Array to hold the output data.
  
      Returns
      -------
      numpy array
          Logistic sigmoid of input data.
  
      """
      # Note: define a wrapper around _sigmoid so we just have the dependency on
      #       madmom when pickling objects, not on scipy.special which may
      #       contain the bug mentioned above
      return _sigmoid(x, out)
  
file_path: madmom/madmom/ml/nn/activations.py
imports: from __future__ import absolute_import, division, print_function
  import numpy
label_desc: Use image node_id 3 for calling a global function with example usage: sigmoid(x, out) and returns: _sigmoid