# Synthesize!
H0 = synthesizeNTF(order, OSR, opt=0)
H1 = synthesizeNTF(order, OSR, opt=1)
# 1. Plot the singularities.
subplot(121)
# we plot the singularities of the optimized NTF in light
# green with slightly bigger markers so that we can better
# distinguish the two NTF's when overlayed.
plotPZ(H1, markersize=7, color='#90EE90')
hold(True)
plotPZ(H0, markersize=5)
title('NTF Poles and Zeros')
f = np.concatenate((np.linspace(0, 0.75/OSR, 100), np.linspace(0.75/OSR, 0.5, 100)))
z = np.exp(2j*np.pi*f)
magH0 = dbv(evalTF(H0, z))
magH1 = dbv(evalTF(H1, z))
# 2. Plot the magnitude responses.
subplot(222)
plot(f, magH0, label='All zeros in z=1')
hold(True)
plot(f, magH1, label='Optimized zeros')
figureMagic([0, 0.5], 0.05, None, [-100, 10], 10, None, (16, 8))
xlabel('Normalized frequency ($1\\rightarrow f_s)$')
ylabel('dB')
legend(loc=4)
title('NTF Magnitude Response')
# 3. Plot the magnitude responses in the signal band.
subplot(224)
fstart = 0.01
f = np.linspace(fstart, 1.2, 200)/(2*OSR)
z = np.exp(2j*np.pi*f)
magH0 = dbv(evalTF(H0, z))
magH1 = dbv(evalTF(H1, z))
semilogx(f*2*OSR, magH0, label='All zeros in z=1')
hold(True)
semilogx(f*2*OSR, magH1, label='Optimized zeros')
axis([fstart, 1.2, -100,- 30])
grid(True)
sigma_H0 = dbv(rmsGain(H0, 0, 0.5/OSR))
sigma_H1 = dbv(rmsGain(H1, 0, 0.5/OSR))
#semilogx([fstart, 1], sigma_H0*np.array([1, 1]))
plot([fstart, 1], sigma_H0*np.array([1, 1]), 'o-')
text(0.15, sigma_H0 + 5, 'RMS gain = %5.0fdB' % sigma_H0)
#semilogx([fstart, 1], sigma_H1*np.array([1, 1]))
plot([fstart, 1], sigma_H1*np.array([1, 1]), 'o-')
text(0.15, sigma_H1 + 5, 'RMS gain = %5.0fdB' % sigma_H1)
xlabel('Normalized frequency ($1\\rightarrow f_B$)')
ylabel('dB')
legend(loc=4)
tight_layout()
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