9月9日，我们怀念毛主席！
代码：
%% ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
%% Output Info about this m-file
fprintf('\n***********************************************************\n');
fprintf(' <DSP using MATLAB> Problem 6.9 \n\n');
banner();
%% ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Klr = [-0.56 2/3 1/2];
Clr = [ 0 0 0 1];
%format rat;
format short;
fprintf('\nConvert Lattice-Ladder-form to Direct-form : \n');
[b, a] = ladr2dir(Klr, Clr)
fprintf('\nConvert matlab Lattice-Ladder-form to Direct-form : \n');
[NUM, DEN] = latc2tf(Klr, Clr)
fprintf('\nConvert DIRECT-form to PARALLEL-form : \n');
[C, Bp, Ap] = dir2par(b, a)
%C = 0;
fprintf('\nConvert DIRECT-form to CASCADE-form : \n');
[b0, Bc, Ac] = dir2cas(b, a)
fprintf('\nConvert TF-form to SOS-form : \n');
[sos, g] = tf2sos(b, a)
fprintf('\nConvert DIRECT-form to LATTICE-LADDER-form : \n');
[Klr, Clr] = dir2ladr(b, a)
fprintf('\nConvert DIRECT-form to MATLAB LATTICE-LADDER-form : \n');
[K, V] = tf2latc(b, a)
% -----------------------------------------
% START check
% -----------------------------------------
n = [0:7];
delta = impseq(0, 0, 7)
%format long
format short
hcas = casfiltr(b0, Bc, Ac, delta)
hpar = parfiltr(C, Bp, Ap, delta)
hladr = ladrfilt(Klr, Clr, delta)
hdir = filter(b, a, delta)
% -------------------------------------------
% END check
% -------------------------------------------
figure('NumberTitle', 'off', 'Name', 'P6.9 hcas(n), hpar(n)')
set(gcf,'Color','white');
subplot(2,1,1); stem(n, hcas);
xlabel('n'); ylabel('hcas(n)');
title('hcas(n)'); grid on;
subplot(2,1,2); stem(n, hpar);
xlabel('n'); ylabel('hpar(n)');
title('hpar(n)'); grid on;
figure('NumberTitle', 'off', 'Name', 'P6.9 hladr(n) hdir(n)')
set(gcf,'Color','white');
subplot(2,1,1); stem(n, hladr);
xlabel('n'); ylabel('hladr(n)');
title('hladr(n)'); grid on;
subplot(2,1,2); stem(n, hdir);
xlabel('n'); ylabel('hdir(n)');
title('hdir(n)'); grid on;
运行结果：
直接形式系数
并联形式系数
串联形式系数
