fuz_or.m

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

function f = fuz_or(method,ua,ub)

% f=fuz_or(method,ua,ub)
%
% Disjunction (OR).
% ua and ub are membershipfunctions or fuzzy sets.
% 'method' determines the typ of the operation:
% 'min'    : Bounded-Sum s1.   uc=min(1;ua+ub).
% 'max'    : Maximum Operator. uc=max(ua;ub).
% 'sum'    : Algebraic-Sum s2. uc=ua+ub - ua*ub.
% 
% The characteristic of the MAXimum operator:
%
% - commutative: op(ua,ub) = op(ub,au).
% - associative: op(ua,ub,uc) = op(op(ua,ub),uc)
% - He is "optimistic" and extrem compensating.
% - He is a member of the triangular-co-norms.
%   These co-t-norms (sometimes called s-norms) are associative,
%   monotonic and kommutative two value functions; used for the
%   disjunction.
% 
% FSTB - Fuzzy Systems Toolbox for MATLAB
% Copyright (c) 1993-1996 by Olaf Wolkenhauer
% Control Systems Centre at UMIST
% Manchester M60 1QD, UK
%
% 24-Feb-1994
 
[m,resx] = size(ua);
if m==4                        % Sets in compact trapezoidal form.
  resx=200;                    % Convert them in the appriote form.
  [ua,ub]=fuz_conv(ua,ub,resx);
end;
% Determine 'method'. Check first three letters.
if all(method=='max'),            % Maximum Operator
  f = max(ua,ub);
elseif all(method=='sum'),        % Algebraic-Sum s2.
  f = ua+ub-ua.*ub;
elseif all(method=='min'),        % Bounded Sum s1
  f = min(ones(1,resx),(ua+ub));
end;