function Lset = Trap2L(par,nol)% Lset = Trap2L(par,nol)%% Converts a trapecoidal fuzzy set specified by the vector% par = [a b c d] into a level set with nol levels. nol=4 would% give the levels [1 0.75 0.5 0.25]. %% The section from b to c describes the flat part of the% trapecoid with level=1.%% FSTB - Fuzzy Systems Toolbox for MATLAB% Copyright (c) 1993-1996 by Olaf Wolkenhauer% Control Systems Centre at UMIST% Manchester M60 1QD, UK%% O.Wolkenhauer 19 July 1996% Last change 19 July 1996Lset = ones(nol,3);Lset(:,1) = (1/nol .* (nol:-1:1) )';a=par(1); b=par(2); c=par(3); d=par(4);Lset(1,2) = b;Lset(1,3) = c;level=Lset(:,1);for i=2:nol,  Lset(i,2) = (b-a)*level(i)+a;  Lset(i,3) = -1*(d-c)*level(i)+d;end;if nargout==0,  plot_set(par');  hold on    plot_Lset(Lset,'c');  hold offend;