fuz_inv.m

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

function f = fuz_inv(f1)

% f=fuz_inv(f1)
%
% Inversion of a (LR-) fuzzy intervalls (number).
% (approximation)
%
% f = [xmin xmax m n alpha beta] 
%   = [xmin xmax 1/m2,1/m1,beta/(m2(m2+beta)),alpha/((m1(m1-alpha))]
%
% ymin=0 and ymax=1 and L=R as conditions.
%
% FSTB - Fuzzy Systems Toolbox for MATLAB
% Copyright (c) 1993-1996 by Olaf Wolkenhauer
% Control Systems Centre at UMIST
% Manchester M60 1QD, UK
%
% 8-Feb-1994

m = f1(3); alpha = f1(5);
n = f1(4); beta  = f1(6);

if fuz_sign(f1)==3;
  error('Error: (LR-) fuzzy-intervall (number) zero.fuz_inv impossible !');
end;

f(1) = f1(1); f(2) = f1(2);           % xmin, xmax
f(3) = 1/n;   f(4) = 1/m;             % m, n
f(5) = beta/(n*(n+beta));             % alpha 
f(6) = alpha/(m*(m-alpha));           % beta