%% ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

%%            Output Info about this m-file

fprintf('\n***********************************************************\n');

fprintf('        <DSP using MATLAB> Problem 6.15 \n\n');

banner();

%% ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

%format long;

format short;

fprintf('\n DIRECT-form:     \n');

b = [1.0  0   -2.20   0  1.6368  0  -0.48928  0  5395456*10^(-8)  0  -147456*10^(-8) ]

a = [1.0  0   -1.65   0  0.8778  0  -0.17281  0  1057221*10^(-8)  0  -893025*10^(-10)]

fprintf('\nConvert DIRECT-form to PARALLEL-form :     \n');

[C, Bp, Ap] = dir2par(b, a)

if size(C)==0

  C = 0;

end

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

% -------------------------------------------

b01 = 1;

Bc1 = [1.0  1.8  0.8;

	   1.0  1.0  0.24;

	   1.0  0.2  0; ];

Ac1 = [1.0  1.6  0.63;

	   1.0  0.8  0.15;

	   1.0  0.1  0;];

fprintf('\nConvert 1st part to DIRECT-form from CASCADE-form :     \n');

[b1, a1] = cas2dir(b01, Bc1, Ac1)

b1 = b1(1:6);

a1 = a1(1:6);

fprintf('\nConvert 1st part to PARALLEL-form from DIRECT-form :     \n');

[C1, Bp1, Ap1] = dir2par(b1, a1)

if size(C1)==0

  C1 = 0;

end

b02 = 1;

Bc2 = [1.0  -1.0  0.24;

	   1.0  -1.8  0.80;

	   1.0  -0.2  0.00; ];

Ac2 = [1.0  -0.8  0.15;

	   1.0  -1.6  0.63;

	   1.0  -0.1  0.00;];

fprintf('\nConvert 2nd part to DIRECT-form from CASCADE-form :     \n');

[b2, a2] = cas2dir(b02, Bc2, Ac2)

b2 = b2(1:6);

a2 = a2(1:6);

fprintf('\nConvert 2nd part to PARALLEL-form from DIRECT-form :     \n');

[C2, Bp2, Ap2] = dir2par(b2, a2)

if size(C2)==0

  C2 = 0;

end