%《MATLAB在電子信息課程中的應(yīng)用》章例618程序
% 線性控制系統(tǒng)的模型描述和轉(zhuǎn)換
% 電子工業(yè)出版社出版  陳懷琛 吳大正 高西全合著 2001年10月

%　由狀態(tài)空間轉(zhuǎn)換為傳遞函數(shù)
clear, 
disp('輸入狀態(tài)方程系數(shù)矩陣A,B,C,D')
disp('輸入A=（書上取[0.2844,0.5828,0.4329,0.5298;0.4692,0.4235,0.2259,0.6405;...')
disp('0.0648,0.5155,0.5798,0.2091;0.9883,0.3340,0.7604,0.3798] }')
A=input('A= ')
B=input('B=（書上取 [0.7833;0.6808;0.4611;0.5678] )') 
C=input('C= （書上取 [0.7942,0.0592,0.6029,0.0503] )'), 
D=input('D= （書上取 0 )')
g=poly(eig(A)); n=length(A);	% 分母多項式系數(shù)由特征根求得
P(:,:,1)=eye(n);
f(1)=D*g(1);						% 分子多項式系數(shù)由遞推求得
f(2)=C*P(:,:,1 )*B+D*g(2);
for i=2:n 
   P(:,:,i )=A*P(:,:,i-1 )+g(i)*eye(n); 
   f(i+1)=C*P(:,:,i )*B+D*g(i+1); 
end
f, g