37 lines
816 B
Python
37 lines
816 B
Python
#!/usr/bin/python3
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import numpy as np
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from lasp import SeriesBiquad, AvPowerSpectra
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from lasp.filter import SPLFilterDesigner
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import matplotlib.pyplot as plt
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from scipy.signal import sosfreqz
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plt.close('all')
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fs = 48000
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omg = 2*np.pi*1000
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filt = SPLFilterDesigner(fs).A_Sos_design()
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bq = SeriesBiquad(filt.flatten())
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tend=10
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t = np.linspace(0, int((tend*fs)//fs), int(tend*fs), endpoint=False)
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in_ = np.random.randn(t.size)
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out = bq.filter(in_)
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from scipy.signal import welch
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nfft = 48000
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freq, H1 = welch(out,
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# scaling
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fs=fs,nfft=nfft)
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freq, H2 = welch(in_,
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# scaling
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fs=fs,nfft=nfft)
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# plt.figure()
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plt.semilogx(freq,10*np.log10(np.abs(H1/H2)))
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omg, H_ex = sosfreqz(filt)
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plt.semilogx(omg/(2*np.pi)*fs, 20*np.log10(np.abs(H_ex)+1e-80))
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