Package fuzzy :: Package norm :: Module FrankUnion
Source Code for Module fuzzy.norm.FrankUnion

 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  __revision__ = "$Id: FrankUnion.py,v 1.7 2009-10-27 20:06:27 rliebscher Exp $" 
20   
21  from fuzzy.norm.ParametricNorm import ParametricNorm 
22  from math import log 
23  from fuzzy.utils import inf_p 
24   
25 -class FrankUnion(ParametricNorm): 
26      """Frank 1979""" 
27       
28      _range = [ (0.,1.),(1.,inf_p) ] 
29       
30 -    def __init__(self, param=0.5): 
31          super(FrankUnion, self).__init__(ParametricNorm.S_NORM, param) 
32   
33 -    def __call__(self, *args): 
34          x, y = self.checkArgs2(args) 
35          p = self.p 
36          return 1.0-log(1.0+(pow(p,1.0-x)-1.0)*(pow(p,1.0-y)-1.0)/(p-1.0))/log(p) 
37