opt_fun.m

控制系统计算机辅助设计——MATLAB语言与应用(源代码）

function y=opt_fun(x,G,key,nn,nd,dc)
%OPT_FUN is used to call by OPT_APP.
%  not recommended to call by hand.

%Designed by Professor Dingyu Xue
%Northeastern University, Shenyang 110004, P R China
%first drafted in 1990, revised for LFC book, 2002
ff0=1e10; alph=[1,x(nn+1:nn+nd)]; 
beta=x(1:nn+1); beta(end)=alph(end)*dc; 
g=tf(beta,alph); 
if key==1, 
   tau=x(end); if tau<=0, tau=eps; end
   [nP,dP]=pade(tau,3); gP=tf(nP,dP);
else,
   gP=1;
end
G_e=G-g*gP;
G_e.num{1}=[0,G_e.num{1}(1:end-1)];
[y,ierr]=geth2(G_e);
if ierr==1, y=10*ff0; else, ff0=y; end