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Source Code for Module fuzzy.set.Trapez

  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  """Realize a trapezoid-shaped fuzzy set.""" 
 20   
 21  __revision__ = "$Id: Trapez.py,v 1.19 2010-10-29 19:24:41 rliebscher Exp $" 
 22   
 23   
 24  from fuzzy.set.Polygon import Polygon 
 25  from fuzzy.utils import prop 
 26  from fuzzy.Exception import FuzzyException 
 27   
 28 -class Trapez(Polygon): 
 29      r""" 
 30      Realize a trapezoid-shaped fuzzy set:: 
 31                 _____ _____  y_max 
 32                /     \ 
 33               /|     |\ 
 34              / |     | \ 
 35             /  |     |  \ 
 36           _/   |     |   \_  y_min 
 37            |   m1    m2  | 
 38            |   |     |   | 
 39           alpha|     |beta 
 40   
 41      See also U{http://pyfuzzy.sourceforge.net/demo/set/Trapez.png} 
 42      """ 
 43   
 44 -    def __init__(self, m1=-0.5, m2=0.5, alpha=0.5, beta=0.5, y_max=1.0, y_min=0.0): 
 45          """ 
 46          Initialize a trapezoid-shaped fuzzy set. 
 47   
 48          @param y_max:  y-value at top of the trapezoid (1.0) 
 49          @param y_min:  y-value outside the trapezoid (0.0) 
 50          @param m1:     x-value of left top of trapezoid (-0.5) 
 51          @param m2:     x-value of right top of trapezoid (0.5) 
 52          @param alpha:  distance of left corner to m1 (0.5) 
 53          @param beta:   distance of right corner to m2 (0.5) 
 54          """ 
 55          super(Trapez, self).__init__() 
 56          self._y_max = float(y_max) 
 57          self._y_min = float(y_min) 
 58          self._m1 = float(m1) 
 59          self._m2 = float(m2) 
 60          self._alpha = float(alpha) 
 61          self._beta = float(beta) 
 62          self._update() # update polygon 
 63   
 64      # pylint: disable=E0211,W0212 
 65      @prop 
 66 -    def y_max(): #@NoSelf 
 67          """y-value at top of the trapezoid 
 68          @type: float""" 
 69          def fget(self): # pylint: disable=W0612,C0111 
 70              return self._y_max 
 71          def fset(self, value): # pylint: disable=W0612,C0111 
 72              self._y_max = float(value) 
 73              self._update() 
 74          return locals() 
 75   
 76      # pylint: disable=E0211,W0212 
 77      @prop 
 78 -    def y_min(): #@NoSelf 
 79          """y-value outside the trapezoid 
 80          @type: float""" 
 81          def fget(self): # pylint: disable=W0612,C0111 
 82              return self._y_min 
 83          def fset(self, value): # pylint: disable=W0612,C0111 
 84              self._y_min = float(value) 
 85              self._update() 
 86          return locals() 
 87   
 88      # pylint: disable=E0211,W0212 
 89      @prop 
 90 -    def m1(): #@NoSelf 
 91          """x-value of left top of trapezoid 
 92          @type: float""" 
 93          def fget(self): # pylint: disable=W0612,C0111 
 94              return self._m1 
 95          def fset(self, value): # pylint: disable=W0612,C0111 
 96              self._m1 = float(value) 
 97              self._update() 
 98          return locals() 
 99   
100      # pylint: disable=E0211,W0212 
101      @prop 
102 -    def m2(): #@NoSelf 
103          """x-value of right top of trapezoid 
104          @type: float""" 
105          def fget(self): # pylint: disable=W0612,C0111 
106              return self._m2 
107          def fset(self, value): # pylint: disable=W0612,C0111 
108              self._m2 = float(value) 
109              self._update() 
110          return locals() 
111   
112      # pylint: disable=E0211,W0212 
113      @prop 
114 -    def alpha(): #@NoSelf 
115          """distance of left corner to m1 
116          @type: float""" 
117          def fget(self): # pylint: disable=W0612,C0111 
118              return self._alpha 
119          def fset(self, value): # pylint: disable=W0612,C0111 
120              self._alpha = float(value) 
121              self._update() 
122          return locals() 
123   
124      # pylint: disable=E0211,W0212 
125      @prop 
126 -    def beta(): #@NoSelf 
127          """distance of right corner to m2 
128          @type: float""" 
129          def fget(self): # pylint: disable=W0612,C0111 
130              return self._beta 
131          def fset(self, value): # pylint: disable=W0612,C0111 
132              self._beta = float(value) 
133              self._update() 
134          return locals() 
135   
136 -    def _update(self): 
137          """update polygon""" 
138          p = super(Trapez, self) 
139          p.clear() 
140          p.add(self._m1-self._alpha, self._y_min) 
141          p.add(self._m1, self._y_max) 
142          p.add(self._m2, self._y_max) 
143          p.add(self._m2+self._beta, self._y_min) 
144   
145 -    def add(self, x, y, where=Polygon.END): 
146          """Don't let anyone destroy our trapezoid.""" 
147          raise FuzzyException() 
148   
149 -    def remove(self, x, where=Polygon.END): 
150          """Don't let anyone destroy our trapezoid.""" 
151          raise FuzzyException() 
152   
153 -    def clear(self): 
154          """Don't let anyone destroy our trapezoid.""" 
155          raise FuzzyException() 
156   
157 -    def __repr__(self): 
158          """Return representation of instance. 
159                      
160             @return: representation of instance 
161             @rtype: string 
162             """ 
163          return "%s.%s(m1=%s, m2=%s, alpha=%s, beta=%s, y_max=%s, y_min=%s)" % ( 
164                  self.__class__.__module__, 
165                  self.__class__.__name__, 
166                  self._m1, 
167                  self._m2, 
168                  self._alpha, 
169                  self._beta, 
170                  self._y_max, 
171                  self._y_min, 
172              ) 
173   

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