function fig_handle = Mysigma(A,B,C,D,e1,e2,titlestring,type); [n,p] = size(B); m = 500; h = (e2-e1)/m; e = zeros(m,1); s = zeros(m,1); for j = 1:m, e(j) = e1 + (j-1)*h; s(j) = 10^e(j); end s = i*s; I = eye(n); w = zeros(m,1); for j = 1:m, w(j) = C*((s(j)*I - A)\B) + D; end w = abs(w); s = abs(s); fig_handle = loglog(s,w,type,'linewidth',1.5); w(m) = w(m)*(1.05); % semilogx(s,w,type,'linewidth',1.5) % semilogx(s(m),w(m)*(1.05),'k.') title(titlestring,'Fontsize',20) ylabel('|G(j\omega)|','Fontsize',15) xlabel('Frequency \omega ','Fontsize',15 )