def compute_normalised_by_order(self,
ap,
n,
aa=None) -> ApproximationErrorCode:
""" Generates normalised transfer function prioritising the fixed order """
# Computing needed constants
zeros, poles, gain = ss.ellipap(n, ap, aa)
self.h_aux = ss.ZerosPolesGain(zeros, poles, gain)
return ApproximationErrorCode.OK
z, p, k = sig.buttap(this_order)
eps = np.sqrt(10**(this_ripple / 10) - 1)
num, den = sig.zpk2tf(z, p, k)
num, den = sig.lp2lp(num, den, eps**(-1 / this_order))
z, p, k = sig.tf2zpk(num, den)
elif aprox_name == 'Chebyshev1':
z, p, k = sig.cheb1ap(this_order, this_ripple)
elif aprox_name == 'Chebyshev2':
z, p, k = sig.cheb2ap(this_order, this_ripple)
elif aprox_name == 'Bessel':
z, p, k = sig.besselap(this_order, norm='mag')
elif aprox_name == 'Cauer':
z, p, k = sig.ellipap(this_order, this_ripple, this_att)
num, den = sig.zpk2tf(z, p, k)
all_sys.append(sig.TransferFunction(num, den))
filter_names.append(aprox_name + '_ord_' + str(this_order) + '_rip_' +
str(this_ripple) + '_att_' + str(this_att))
analyze_sys(all_sys, filter_names)
elif aprox_name == 'Chebyshev1':
z, p, k = sig.cheb1ap(order2analyze, ripple)
elif aprox_name == 'Chebyshev2':
z, p, k = sig.cheb2ap(order2analyze, ripple)
elif aprox_name == 'Bessel':
z, p, k = sig.besselap(order2analyze, norm='mag')
elif aprox_name == 'Cauer':
z, p, k = sig.ellipap(order2analyze, ripple, attenuation)
num, den = sig.zpk2tf(z, p, k)
# Desnormalizamos para wc
num, den = sig.lp2lp(num, den, 2 * np.pi * fc)
my_analog_filter = sig.TransferFunction(num, den)
my_analog_filter_desc = aprox_name + '_ord_' + str(order2analyze) + '_analog'
all_sys.append(my_analog_filter)
filter_names.append(my_analog_filter_desc)
analog_filters.append(my_analog_filter)
analog_filters_names.append(my_analog_filter_desc)
if aprox_name == 'Butterworth':
z,p,k = sig.buttap(ii)
elif aprox_name == 'Chebyshev1':
z,p,k = sig.cheb1ap(ii, ripple)
elif aprox_name == 'Chebyshev2':
z,p,k = sig.cheb2ap(ii, ripple)
elif aprox_name == 'Bessel':
z,p,k = sig.besselap(ii, norm='mag')
elif aprox_name == 'Cauer':
z,p,k = sig.ellipap(ii, ripple, attenuation)
num, den = sig.zpk2tf(z,p,k)
all_sys.append(sig.TransferFunction(num,den))
filter_names.append(aprox_name + '_ord_' + str(ii))
analyze_sys( all_sys, filter_names )
this_order = force_order
else:
this_order = besselord(omega_p, omega_s, alfa_max, alfa_min, omega_d,
max_pc_delay)
z, p, k = sig.besselap(this_order, norm='mag')
elif aprox_name == 'Cauer':
if force_order > 0:
this_order = force_order
else:
this_order, _ = sig.ellipord(omega_p,
omega_s,
alfa_max,
alfa_min,
analog=True)
z, p, k = sig.ellipap(this_order, alfa_max, alfa_min)
if (tipo_de_filtro == "Pasa_Alto"):
z, p, k = sig.lp2hp_zpk(z, p, k)
this_lti = sig.ZerosPolesGain(z, p, k).to_tf()
#this_lti = sig.ZerosPolesGain(z, p, k).to_tf()
pretty_print_lti(this_lti)
analyze_sys([this_lti], [aprox_name], [ideal_filter])
def main():
random.seed(7)
np.random.seed(7)
fs = 200 # Hz
fo = 40 # Hz
rp = 1 # dB
rs = 80 # dB
fpass = fo - 5 # Hz
fstop = fo + 5 # Hz
# N, fo = signal.cheb1ord(fpass, fstop, rp, rs, fs=fs)
# N, fo = signal.cheb2ord(fpass, fstop, rp, rs, fs=fs)
# N, fo = signal.buttord(fpass, fstop, rp, rs, fs=fs)
N, fo = signal.ellipord(fpass, fstop, rp, rs, fs=fs)
wp = 2 * fs * np.tan(np.pi * fo / fs)
# prototype = signal.lti(*signal.cheb1ap(N, rp))
# prototype = signal.lti(*signal.cheb2ap(N, rs))
# prototype = signal.lti(*signal.buttap(N))
prototype = signal.lti(*signal.ellipap(N=N, rp=rp, rs=rs))
model = lowpass_to_lowpass(prototype, wo=wp)
model = discretize(model, dt=1 / fs)
print(model)
# Use PSD output to white noise input PSD ratio as response
window = signal.get_window('blackman', 256)
psd = functools.partial(signal.welch,
scaling='density',
window=window,
fs=fs)
input_range = interval(lower_bound=-0.5, upper_bound=0.5)
input_noise_power_density = 0.0005
input_noise = np.random.normal(scale=np.sqrt(input_noise_power_density *
fs / 2),
size=512)
assert np.max(input_noise) < ProcessingUnit.active().rinfo().max
assert np.min(input_noise) > ProcessingUnit.active().rinfo().min
input_noise = np.array([fixed(n) for n in input_noise])
_, outputs = model.output(input_noise.astype(float), t=None)
output_noise = outputs.T[0]
freq, output_noise_power_density = psd(output_noise)
expected_response = 10 * np.log10(output_noise_power_density /
input_noise_power_density + 1 / inf)
# Take quantization noise into account
noise_floor = -6.02 * (ProcessingUnit.active().wordlength - 1) - 1.76
expected_response = np.maximum(expected_response, noise_floor)
# Formulate GP problem
toolbox = solvers.gp.formulate(
prototype,
transforms=[
functools.partial(lowpass_to_lowpass, wo=wp),
functools.partial(discretize, dt=1 / fs)
],
evaluate=functools.partial(
evaluate,
input_range=input_range,
input_noise=input_noise,
input_noise_power_density=input_noise_power_density,
psd=psd,
expected_response=expected_response),
weights=(1., 1., 1., 1., -1., -1., -1., -1.),
forms=[DirectFormI, DirectFormII],
variants=range(1000),
dtype=fixed,
tol=1e-6)
# Solve GP problem
only_visualize = False
if not only_visualize:
with multiprocessing.Pool() as pool:
try:
toolbox.register('map', pool.map)
stats = deap.tools.Statistics(
key=lambda code: code.fitness.values)
stats.register('avg', np.mean, axis=0)
stats.register('med', np.median, axis=0)
stats.register('min', np.min, axis=0)
pareto_front = deap.tools.ParetoFront()
population = toolbox.population(512)
population, logbook = solvers.gp.nsga2(population,
toolbox,
mu=512,
lambda_=128,
cxpb=0.5,
mutpb=0.05,
ngen=25,
stats=stats,
halloffame=pareto_front,
verbose=True)
finally:
toolbox.register('map', map)
with open('front.pkl', 'wb') as f:
pickle.dump(pareto_front, f)
with open('logbook.pkl', 'wb') as f:
pickle.dump(logbook, f)
else:
with open('front.pkl', 'rb') as f:
pareto_front = pickle.load(f)
with open('logbook.pkl', 'rb') as f:
logbook = pickle.load(f)
codes = []
criteria = []
for code in pareto_front:
crt = Criteria(*code.fitness.values)
if crt.frequency_response_error >= inf:
continue
if crt.stability_margin <= 0:
continue
if crt.overflow_margin < 0:
continue
if crt.underflow_margin < 0:
continue
codes.append(code)
criteria.append(crt)
frequency_response_error = np.array(
[crt.frequency_response_error for crt in criteria])
arithmetic_snr = np.array([crt.arithmetic_snr for crt in criteria])
stability_margin = np.array([crt.stability_margin for crt in criteria])
memory_size = np.array([crt.size_of_memory for crt in criteria])
memory_size_in_bytes = memory_size * ProcessingUnit.active().wordlength / 8
plt.figure()
gen, med = logbook.select('gen', 'med')
crt = Criteria(*np.array(med).T)
def fit_most_within_unit_interval(values):
values = np.asarray(values)
med = np.median(values)
mad = np.median(np.absolute(values - med))
if not mad:
return values
return (values - med) / (4. * mad)
plt.plot(gen,
fit_most_within_unit_interval(crt.overflow_margin),
label='Med[$M_o$]')
plt.plot(gen,
fit_most_within_unit_interval(crt.underflow_margin),
label='Med[$M_u$]')
plt.plot(gen,
fit_most_within_unit_interval(crt.stability_margin),
label='Med[$M_s$]')
plt.plot(gen,
fit_most_within_unit_interval(crt.arithmetic_snr),
label='Med[$SNR_{arit}$]')
plt.plot(gen,
fit_most_within_unit_interval(crt.frequency_response_error),
label='Med[$E_2$]')
plt.plot(gen,
fit_most_within_unit_interval(crt.number_of_adders),
label='Med[$N_a$]')
plt.plot(gen,
fit_most_within_unit_interval(crt.number_of_multipliers),
label='Med[$N_m$]')
plt.plot(gen,
fit_most_within_unit_interval(crt.size_of_memory),
label='Med[$N_e$]')
plt.ylabel('Normalized evolution')
plt.xlabel('Generations')
plt.ylim([-10, 10])
plt.legend(loc='upper right')
plt.savefig('population_evolution.png')
plt.figure()
plt.plot(*logbook.select('gen', 'nunfeas'))
plt.ylabel('Unfeasibles')
plt.xlabel('Generations')
plt.savefig('unfeasibles.png')
def pareto2d(ax, x, y):
ax.scatter(x, y, marker='o', facecolors='none', edgecolors='r')
idx = np.argsort(x)
ax.plot(x[idx], y[idx], 'k--')
fig = plt.figure()
ax = fig.add_subplot(3, 1, 1)
idx = solvers.gp.argnondominated(-frequency_response_error,
stability_margin)
pareto2d(ax, frequency_response_error[idx], stability_margin[idx])
ax.set_ylabel('Margin $M_s$')
ax.invert_xaxis()
ax = fig.add_subplot(3, 1, 2)
idx = solvers.gp.argnondominated(-frequency_response_error, arithmetic_snr)
pareto2d(ax, frequency_response_error[idx], arithmetic_snr[idx])
ax.set_ylabel('$SNR_{arit}$ [dBr]')
ax.invert_xaxis()
ax = fig.add_subplot(3, 1, 3)
idx = solvers.gp.argnondominated(-frequency_response_error,
-memory_size_in_bytes)
pareto2d(ax, frequency_response_error[idx], memory_size_in_bytes[idx])
ax.set_xlabel('Error $E_2$ [dBr]')
ax.set_ylabel('Total $N_e$ @ Q15 [bytes]')
ax.invert_xaxis()
ax.invert_yaxis()
plt.savefig('pareto_fronts.png')
fig = plt.figure()
ax = fig.add_subplot(projection='3d')
idx = solvers.gp.argnondominated(-frequency_response_error, arithmetic_snr,
-memory_size_in_bytes)
scatter = ax.scatter(frequency_response_error[idx],
arithmetic_snr[idx],
memory_size_in_bytes[idx],
c=stability_margin[idx],
cmap='jet_r')
fig.colorbar(scatter, ax=ax, label='Margin $M_s$')
ax.set_xlabel('Error $E_2$ [dBr]')
ax.set_ylabel('$SNR_{arit}$ [dBr]')
ax.set_zlabel('Total $N_e$ @ Q15 [bytes]')
ax.invert_xaxis()
ax.invert_zaxis()
plt.savefig('pareto_sampling.png')
index = np.argsort(frequency_response_error)[0]
implement = toolbox.compile(codes[index])
optimized_implementation_a = implement(prototype)
index = np.argsort(frequency_response_error)[3]
implement = toolbox.compile(codes[index])
optimized_implementation_b = implement(prototype)
print(memory_size_in_bytes[np.argsort(frequency_response_error)])
print(stability_margin[np.argsort(frequency_response_error)])
print(arithmetic_snr[np.argsort(frequency_response_error)])
pretty(optimized_implementation_a).draw('optimized_a.png')
pretty(optimized_implementation_b).draw('optimized_b.png')
func = signal_processing_function(optimized_implementation_a)
output_noise = func(input_noise).T[0].astype(float)
_, output_noise_power_density = psd(output_noise)
optimized_implementation_a_response = \
10 * np.log10(output_noise_power_density / input_noise_power_density + 1/inf)
func = signal_processing_function(optimized_implementation_b)
output_noise = func(input_noise).T[0].astype(float)
_, output_noise_power_density = psd(output_noise)
optimized_implementation_b_response = \
10 * np.log10(output_noise_power_density / input_noise_power_density + 1/inf)
show_biquad_cascade = True
if show_biquad_cascade:
biquad_cascade = series_diagram([
DirectFormI.from_model(signal.dlti(
section[:3], section[3:], dt=model.dt),
dtype=fixed)
for section in signal.zpk2sos(model.zeros, model.poles, model.gain)
],
simplify=False)
pretty(biquad_cascade).draw('biquad.png')
func = signal_processing_function(biquad_cascade)
output_noise = func(input_noise).T[0].astype(float)
_, output_noise_power_density = psd(output_noise)
biquad_cascade_response = \
10 * np.log10(output_noise_power_density / input_noise_power_density + 1/inf)
plt.figure()
plt.plot(freq, expected_response, label='Model')
if show_biquad_cascade:
plt.plot(freq, biquad_cascade_response, label='Biquad cascade')
pass
plt.plot(freq,
optimized_implementation_a_response,
label='Optimized realization A')
plt.plot(freq,
optimized_implementation_b_response,
label='Optimized realization B')
plt.xlabel('Frecuency $f$ [Hz]')
plt.ylabel('Response $|H(f)|$ [dBr]')
plt.legend()
plt.savefig('response.png')
plt.show()