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Source Code for Module fuzzy.System

  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  """Main coordinator class of a whole fuzzy system""" 
 20   
 21  __revision__ = "$Id: System.py,v 1.19 2010-02-17 19:57:13 rliebscher Exp $" 
 22   
 23 -class System(object): 
 24      """Holds all stuff together. (variables, rules, ...) 
 25          Provides methods to do calculation with it. 
 26           
 27          @ivar variables: dictionary to hold all variables. 
 28          @type variables: {string:L{fuzzy.Variable.Variable}} 
 29          @ivar rules: dictionary to hold all rules. 
 30          @type rules: {string:L{fuzzy.Rule.Rule}} 
 31          @ivar description: description 
 32          @type description: string 
 33      """  
 34   
 35 -    def __init__(self, description="", variables = None, rules = None): 
 36          """Constructor. 
 37   
 38          @param description: description 
 39          @type description: string 
 40          """ 
 41          self.variables = variables or {} 
 42          self.rules = variables or {} 
 43          self.description = description 
 44   
 45 -    def reset(self): 
 46          """Reset all memberships for the next run of calculate""" 
 47          for variable in self.variables.values(): 
 48              variable.reset() 
 49   
 50 -    def fuzzify(self, input): 
 51          """Fuzzify the inputs. 
 52          The input dictionary contains the input values for the named variables.""" 
 53   
 54          # feed input values in variables and so in adjectives 
 55          for (name, value) in input.items(): 
 56              if name in self.variables: 
 57                  self.variables[name].setValue(value) 
 58              #else: 
 59              #   print "ignored input ",name 
 60   
 61   
 62 -    def inference(self): 
 63          """Calculate the fuzzy inference given by the rules.""" 
 64   
 65          # compute fuzzy rules  
 66          for rule in self.rules.values(): 
 67              rule.compute() 
 68   
 69   
 70 -    def defuzzify(self, output): 
 71          """Defuzzyfy the variables. 
 72          The output dictionary serves as container and provides the names of the 
 73          variables to read.""" 
 74   
 75          # get all wanted output variables 
 76          for name in output.keys(): 
 77              output[name] = self.variables[name].getValue() 
 78   
 79          return output 
 80   
 81   
 82 -    def calculate(self, input, output): 
 83          """Do a complete fuzzy calculation step. 
 84          The input dictionary contains the input values for the named variables. 
 85          The output dictionary serves as container and provides the names of the 
 86          variables to read.""" 
 87   
 88          self.reset() 
 89   
 90          self.fuzzify(input) 
 91   
 92          self.inference() 
 93   
 94          self.defuzzify(output) 
 95   
 96          return output 
 97   
 98   
 99 -    def findVariableName(self, var): 
100          """Find name of variable in this system""" 
101          for name, variable in self.variables.items(): 
102              if var is variable: 
103                  return name 
104          return None 
105   
106 -    def findAdjectiveName(self, adj): 
107          """Find name of adjective (and variable) in this system""" 
108          for name, variable in self.variables.items(): 
109              for namea, adjective in variable.adjectives.items(): 
110                  if adj is adjective: 
111                      return [namea, name] 
112          return None 
113   
114 -    def findRuleName(self, _rule): 
115          """Find name of rule in this system""" 
116          for name, rule in self.rules.items(): 
117              if _rule is rule: 
118                  return name 
119          return None 
120   
121 -    def __repr__(self): 
122          """Return representation of instance. 
123                      
124             @return: representation of instance 
125             @rtype: string 
126             """ 
127          params = [] 
128          if self.description: params.append("description=%s" % repr(self.description)) 
129          if self.variables: params.append("variables=%s" % repr(self.variables)) 
130          if self.rules: params.append("rules=%s" % repr(self.rules)) 
131          return "%s.%s(%s)" % (self.__class__.__module__, self.__class__.__name__, ", ".join(params)) 
132   

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