match.m

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

function A=match(X,xi,setlib)

% A=match(X,xi,setlib)
%
% The function is realizing the fuzzification.
% For a given "crisp" input value xi, this function uses a 
% binary unit vector of the same length of X (universe of 
% discourse) with a single 1 element in the ith slot.
% This binary unit vector is multiplied with each vector 
% representing a membershipfunction in the set-library setlib.
% A then is a row vector containing the fit-value to which the
% crisp input xi fits to the corresponding set.
%
% FSTB - Fuzzy Systems Toolbox for MATLAB
% Copyright (c) 1993-1996 by Olaf Wolkenhauer
% Control Systems Centre at UMIST
% Manchester M60 1QD, UK
%  
% 19-April-1994

% note: later may be better to pass xmin and xmax directly.
[m,n] = size(X);
% limiting xi to the universe of discourse. That means each xi 
% outside the range is set equal to the range limits and gets the
% corresponding fit value.
xmin  = X(1,1); xmax = X(1,n); dx = xmax-xmin;
xi=max(xi,xmin); xi=min(xi,xmax); 
slot  = max(1,round(n*(xi-xmin)/dx));
% To save computational effort, not binary unit vector is generated and
% used.
A=setlib(:,slot);
% A is a collumn vector containing the fit values from the given
% crisp input xi to all 'ling. terms' of the 'ling. var.'.