code: def liu_storey(old_g, new_g, delta_w, epsilon=1e-7):
      return -safe_division(
          dot(new_g, new_g - old_g),
          dot(delta_w, old_g),
          epsilon,
      )
  
file_path: neupy/neupy/algorithms/gd/conjgrad.py
imports: import tensorflow
  from neupy.utils import dot, function_name_scope, asfloat, make_single_vector
  from neupy.core.properties import ChoiceProperty, NumberProperty, WithdrawProperty
  from neupy.utils.tf_utils import setup_parameter_updates
  from .base import BaseOptimizer
  from .quasi_newton import safe_division, WolfeLineSearchForStep
label_desc: Use image node_id 4 for calling a global function with example usage: liu_storey(old_g, new_g, delta_w, epsilon) and returns: unknown