rtinf.m

FISMAT accommodates different arithmetic operators, fuzzification and defuzzification algorithm, imp

function [rb,mtab] = rtinf(rt,e,de,andop,orop)

% [rb,mtab] = rtinf(rt,andop,orop)
%
% Inference of a two-dimensional fuzzy-controller given by a ruletable.
% rb = A vector containing the premise results for each rule.
% The composition and defuzzification must follow after calling this 
% function.
% rt = A matrix, the ruletable.
% mtab = optional result matrix of the conjunction for every rule.
% e,de = row vectors containing the membership of both crip values from e
% and de for every linguistic term of each ling. variable e and de.
% These vectors are produced by fuzzification routines.
% andop = the t-norm operator for the conjunction. (given as a string)
% orop  = the s-norm operator for the disjunction. (given as a string)
% Other operators possible. There must be only two input values and one
% output-return value.
% The orientation of the ruletable is defined as e in the horizontal and de
% in the vertical orientation.
% The membership and the ling. terms begin from the left with index one for
% the lowest ling. value e.g ling. term like Negative Big.
% The first row of de correspond to the index one and the lowest ling. value
% Not used arrays must filled with zeros.
%
% FSTB - Fuzzy Systems Toolbox for MATLAB
% Copyright (c) 1993-1996 by Olaf Wolkenhauer
% Control Systems Centre at UMIST
% Manchester M60 1QD, UK
%
% 10-August 1993
 
[r,c]=size(rt);
mtab=zeros(r,c);
for i=1:c,
  for j=1:r,
    mtab(j,i)=feval(andop,e(i),de(j));
  end;
end;
% mtab now contains the results of the conjunction for every rule.
mav=max(max(rt)); % mav=number of ling. terms of the output-set.
rb=zeros(mav,1);  % the disjunction beetween the results of every rule with
                  % the same linguistic output-term is following : 
for i=1:mav,      % for every ling. term of the output-set.
  iv=find(rt==i); % iv=list of indices which correspond two one ling. term.
  if length(iv)>1,
    zw=feval(orop,mtab(iv(1)),mtab(iv(2)));
    for n=3:length(iv),
      zw=feval(orop,zw,mtab(iv(n)));
    end;
    rb(i)=zw;
  else 
    rb(i)=mtab(iv); 
  end;            % there is only one rule with this ling. output
end;