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Source Code for Module fuzzy.defuzzify.Base

  1  # -*- coding: utf-8 -*- 
  2  # 
  3  # Copyright (C) 2009  Rene Liebscher 
  4  # 
  5  # This program is free software; you can redistribute it and/or modify it under 
  6  # the terms of the GNU Lesser General Public License as published by the Free  
  7  # Software Foundation; either version 3 of the License, or (at your option) any 
  8  # later version. 
  9  # 
 10  # This program is distributed in the hope that it will be useful, but WITHOUT  
 11  # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 
 12  # FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more 
 13  # details. 
 14  #  
 15  # You should have received a copy of the GNU Lesser General Public License 
 16  # along with this program; if not, see <http://www.gnu.org/licenses/>.  
 17  # 
 18   
 19  """Abstract base class for defuzzification which results in a numeric value.""" 
 20   
 21  __revision__ = "$Id: Base.py,v 1.12 2010-03-28 18:40:33 rliebscher Exp $" 
 22   
 23   
 24  from fuzzy.norm.Max import Max 
 25  from fuzzy.norm.Min import Min 
 26  from fuzzy.set.Set import norm, merge 
 27  from fuzzy.Exception import FuzzyException 
 28   
 29 -class DefuzzificationException(FuzzyException): 
 30      pass 
 31   
 32 -class Base(object): 
 33      """Abstract base class for defuzzification 
 34         which results in a numeric value. 
 35          
 36          @ivar INF: inference norm, used with set of adjective and given value for it 
 37          @type INF: L{fuzzy.norm.Norm.Norm} 
 38          @ivar ACC: norm for accumulation of set of adjectives 
 39          @type ACC: L{fuzzy.norm.Norm.Norm} 
 40          @cvar _INF: default value when INF is None 
 41          @type _INF: L{fuzzy.norm.Norm.Norm} 
 42          @cvar _ACC: default value when ACC is None 
 43          @type _ACC: L{fuzzy.norm.Norm.Norm} 
 44          @ivar activated_sets: results of activation of adjectives of variable. 
 45          @type activated_sets: {string:L{fuzzy.set.Polygon.Polygon}} 
 46          @ivar accumulated_set: result of accumulation of activated sets 
 47          @type accumulated_set: L{fuzzy.set.Polygon.Polygon} 
 48         """ 
 49   
 50      # default values if instance values are not set  
 51      _INF = Min() 
 52      _ACC = Max() 
 53   
 54 -    def __init__(self, INF=None, ACC=None): 
 55          """ 
 56          @param INF: inference norm, used with set of adjective and given value for it 
 57          @type INF: L{fuzzy.norm.Norm.Norm} 
 58          @param ACC: norm for accumulation of set of adjectives 
 59          @type ACC: L{fuzzy.norm.Norm.Norm} 
 60          """ 
 61          self.ACC = ACC # accumulation 
 62          self.INF = INF # inference 
 63          self.activated_sets = {} 
 64          self.accumulated_set = None 
 65   
 66 -    def getValue(self, variable): 
 67          """Defuzzification.""" 
 68          raise NotImplementedError("don't use the abstract base class") 
 69   
 70  # helper methods for sub classes 
 71   
 72 -    def accumulate(self, variable, segment_size=None): 
 73          """combining adjective values into one set""" 
 74          self.activated_sets = {} 
 75          temp = None 
 76          for name, adjective in variable.adjectives.items(): 
 77              # get precomputed adjective set 
 78              temp2 = norm((self.INF or self._INF), adjective.set, adjective.getMembership(), segment_size) 
 79              self.activated_sets[name] = temp2 
 80              # accumulate all adjectives 
 81              if temp is None: 
 82                  temp = temp2 
 83              else: 
 84                  temp = merge((self.ACC or self._ACC), temp, temp2, segment_size) 
 85          self.accumulated_set = temp 
 86          return temp 
 87   
 88 -    def value_table(self, set): 
 89          """get a value table of the polygon representation""" 
 90          # get polygon representation 
 91          return set.getValuesXY() 
 92       
 93 -    def __repr__(self): 
 94          """Return representation of instance. 
 95                      
 96             @return: representation of instance 
 97             @rtype: string 
 98             """ 
 99          params = [] 
100          self._repr_params(params) 
101          return "%s.%s(%s)" % (self.__class__.__module__, self.__class__.__name__, ", ".join(params)) 
102   
103 -    def _repr_params(self, params): 
104          """Helper for representation of instance. 
105           
106          Add all own params to given list in params.     
107          """ 
108          if self.INF: params.append("INF=%s" % repr(self.INF))  
109          if self.ACC: params.append("ACC=%s" % repr(self.ACC)) 
110   

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