《DSP using MATLAB》Problem 6.9

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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