% Chapter 7: Example 7.17%            Freq. Samp. Tech.: Bandpass, Optimum method T1 & T2%            ws1=0.2pi, wp1=0.35pi, wp2=0.65pi, ws2=0.8pi, Rp=1dB, As=60dB%            T2 = 0.59417456, T1=0.109021M = 40; alpha = (M-1)/2; l = 0:M-1; wl = (2*pi/M)*l;T1 = 0.109021; T2 = 0.59417456;Hrs = [zeros(1,5),T1,T2,ones(1,7),T2,T1,zeros(1,9),T1,T2,ones(1,7),T2,T1,zeros(1,4)];Hdr = [0,0,1,1,0,0]; wdl = [0,0.2,0.35,0.65,0.8,1];k1 = 0:floor((M-1)/2); k2 = floor((M-1)/2)+1:M-1;angH = [-alpha*(2*pi)/M*k1, alpha*(2*pi)/M*(M-k2)];H = Hrs.*exp(j*angH);h = real(ifft(H,M));[db,mag,pha,grd,w] = freqz_m(h,1);[Hr,ww,a,L] = Hr_Type2(h);subplot(1,1,1)subplot(2,2,1);plot(wl(1:21)/pi,Hrs(1:21),'o',wdl,Hdr); axis([0,1,-0.1,1.1]); title('Bandpass: M=40,T1=0.5941, T2=0.109')xlabel('frequency in pi units'); ylabel('Hr(k)')set(gca,'XTickMode','manual','XTick',[0,0.2,0.35,0.65,0.8,1])set(gca,'YTickMode','manual','YTick',[0,0.59,0.109,1]); gridsubplot(2,2,2); stem(l,h); axis([-1,M,-0.4,0.4])title('Impulse Response'); xlabel('n'); ylabel('h(n)');subplot(2,2,3); plot(ww/pi,Hr,wl(1:21)/pi,Hrs(1:21),'o');axis([0,1,-0.1,1.1]); title('Amplitude Response')xlabel('frequency in pi units'); ylabel('Hr(w)')set(gca,'XTickMode','manual','XTick',[0,0.2,0.35,0.65,0.8,1])set(gca,'YTickMode','manual','YTick',[0,0.59,0.109,1]); gridsubplot(2,2,4);plot(w/pi,db); axis([0,1,-100,10]); gridtitle('Magnitude Response'); xlabel('frequency in pi units');ylabel('Decibels');set(gca,'XTickMode','Manual','XTick',[0,0.2,0.35,0.65,0.8,1]);set(gca,'YTickMode','Manual','YTick',[-60;0]);set(gca,'YTickLabelMode','manual','YTickLabels',['60';' 0'])%