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%%            Output Info about this m-file

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

fprintf('        <DSP using MATLAB> Problem 7.10 \n\n');

banner();

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wp1 = 0.3*pi; ws1 = 0.4*pi; ws2 = 0.6*pi; wp2 = 0.7*pi;

As = 50; Rp = 0.2;

tr_width = min( ws1-wp1, wp2-ws2 );

M = ceil(6.6*pi/tr_width) + 1;                 % Hamming Window

fprintf('\nFilter Length is %d.\n', M);

n = [0:1:M-1];  wc1 = (ws1+wp1)/2; wc2 = (wp2+ws2)/2;

%wc = (ws + wp)/2,                    % ideal LPF cutoff frequency

hd = ideal_lp(wc1, M) + ideal_lp(pi, M) - ideal_lp(wc2, M);

w_ham = (hamming(M))';  h = hd .* w_ham;

[db, mag, pha, grd, w] = freqz_m(h, [1]);  delta_w = 2*pi/1000;

[Hr,ww,P,L] = ampl_res(h);

Rp = -(min(db(1 : 1 : wp1/delta_w+1)));             % Actual Passband Ripple

fprintf('\nActual Passband Ripple is %.4f dB.\n', Rp);

As = -round(max(db(ws1/delta_w+1 : 1 : ws2/delta_w)));        % Min Stopband attenuation

fprintf('\nMin Stopband attenuation is %.4f dB.\n', As);

[delta1, delta2] = db2delta(Rp, As)

%Plot

figure('NumberTitle', 'off', 'Name', 'Problem 7.10 ideal_lp Method')

set(gcf,'Color','white'); 

subplot(2,2,1); stem(n, hd); axis([0 M-1 -0.2 0.8]); grid on;

xlabel('n'); ylabel('hd(n)'); title('Ideal Impulse Response');

subplot(2,2,2); stem(n, w_ham); axis([0 M-1 0 1.1]); grid on;

xlabel('n'); ylabel('w(n)'); title('Hamming Window');

subplot(2,2,3); stem(n, h); axis([0 M-1 -0.2 0.8]); grid on;

xlabel('n'); ylabel('h(n)'); title('Actual Impulse Response');

subplot(2,2,4); plot(w/pi, db); axis([0 1 -120 10]); grid on;

set(gca,'YTickMode','manual','YTick',[-90,-50,0]);

set(gca,'YTickLabelMode','manual','YTickLabel',['90';'50';' 0']);

set(gca,'XTickMode','manual','XTick',[0,0.3,0.4,0.6,0.7,1]);

xlabel('frequency in \pi units'); ylabel('Decibels'); title('Magnitude Response in dB');

figure('NumberTitle', 'off', 'Name', 'Problem 7.10 h(n) ideal_lp Method')

set(gcf,'Color','white'); 

subplot(2,2,1); plot(w/pi, db); grid on; axis([0 1 -120 10]);

set(gca,'YTickMode','manual','YTick',[-90,-50,0])

set(gca,'YTickLabelMode','manual','YTickLabel',['90';'50';' 0']);

set(gca,'XTickMode','manual','XTick',[0,0.3,0.4,0.6,0.7,1]);

xlabel('frequency in \pi units'); ylabel('Decibels'); title('Magnitude Response in dB');

subplot(2,2,3); plot(w/pi, mag); grid on; %axis([0 1 -100 10]);

xlabel('frequency in \pi units'); ylabel('Absolute'); title('Magnitude Response in absolute');

set(gca,'XTickMode','manual','XTick',[0,0.3,0.4,0.6,0.7,1,1.3,1.4,1.6,1.7,2]);

set(gca,'YTickMode','manual','YTick',[0,1.0]);

subplot(2,2,2); plot(w/pi, pha); grid on; %axis([0 1 -100 10]);

xlabel('frequency in \pi units'); ylabel('Rad'); title('Phase Response in Radians');

subplot(2,2,4); plot(w/pi, grd*pi/180);  grid on; %axis([0 1 -100 10]);

xlabel('frequency in \pi units'); ylabel('Rad'); title('Group Delay');

figure('NumberTitle', 'off', 'Name', 'Problem 7.10 h(n)')

set(gcf,'Color','white'); 

plot(ww/pi, Hr); grid on; %axis([0 1 -100 10]);

xlabel('frequency in \pi units'); ylabel('Hr'); title('Amplitude Response');

set(gca,'YTickMode','manual','YTick',[-0.0032, 0,0.0032, 0.9975, 1,1.0025]);

%set(gca,'YTickLabelMode','manual','YTickLabel',['90';'45';' 0']);

%set(gca,'XTickMode','manual','XTick',[0,0.2,0.35,0.55,0.75,1,1.2,1.35,1.55,1.75,2]);