《DSP using MATLAB》Problem 6.12

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%%            Output Info about this m-file
fprintf(‘\n***********************************************************\n‘);
fprintf(‘        <DSP using MATLAB> Problem 6.12 \n\n‘);

banner();
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b = [0.05  -0.01  -0.13   0.00  0.13   0.01  -0.05];  
a = [1.00  -0.77   1.59  -0.88  1.20  -0.35   0.31]; 

format short;
fprintf(‘\nConvert DIRECT-form to PARALLEL-form :     \n‘);
[C, Bp, Ap] = dir2par(b, a)
%C = 0;

a11 = conv(Ap(1, :), Ap(2, :))
b11 = conv(Bp(1, :), Ap(2, :)) + conv(Bp(2, :), Ap(1, :))

b11 = [b11, zeros(1,length(a11)-length(b11))]
b12 = -0.1613*a11 + b11

fprintf(‘\nConvert DIRECT-form to CASCADE-form :     \n‘);
[b0, Bc, Ac] = dir2cas(b12, a11) 

fprintf(‘\nConvert TF-form to SOS-form :     \n‘);
[sos, g] = tf2sos(b12, a11)