code: def decay_function(value, epoch, reduction_rate):
      """
      Applies to the input value monophonic decay.
  
      Parameters
      ----------
      value : int, float
  
      epoch : int
          Current training iteration (epoch).
  
      reduction_rate : int
          The larger the value the slower decay]
      """
      return value / (1 + epoch / reduction_rate)
  
imports: from __future__ import division
  from collections import namedtuple
  import six
  import numpy
  from numpy.linalg import norm
  from neupy import init
  from neupy.utils import as_tuple, format_data
  from neupy.algorithms import Kohonen
  from neupy.exceptions import WeightInitializationError
  from neupy.algorithms.associative.base import BaseAssociative
  from neupy.core.properties import BaseProperty, TypedListProperty, ChoiceProperty, NumberProperty, ParameterProperty, IntProperty
  from .randomized_pca import randomized_pca
  from .neighbours import find_step_scaler_on_rect_grid, find_neighbours_on_rect_grid, find_neighbours_on_hexagon_grid, find_step_scaler_on_hexagon_grid
label_desc: Use image node_id 3 for calling a global function with example usage: decay_function(value, epoch, reduction_rate) and returns: unknown