44 lines
973 B
Python
44 lines
973 B
Python
"""
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Estimate the magnitude squared coherence estimate,
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- requirements
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sudo apt install python-numpy python-scipy python-matplotlib
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"""
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import sys
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import wave
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import numpy as np
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from scipy import signal
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import matplotlib.pyplot as plt
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if len(sys.argv) < 2:
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print('Usage: python {} audio.wav'.format(sys.argv[0]))
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sys.exit(1)
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wav = wave.open(sys.argv[1], 'rb')
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channels = wav.getnchannels()
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frames = wav.readframes(wav.getnframes())
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fs = wav.getframerate()
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wav.close()
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print("channels: %d" % channels)
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print("rate : %d" % fs)
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print("frames : %d" % wav.getnframes())
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array = np.fromstring(frames, dtype='int16')
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ch0 = array[0::channels]
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fig, ax = plt.subplots()
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for ch in range(1, channels):
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f, c = signal.coherence(ch0, array[ch::channels], fs, nperseg=1024)
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ax.semilogy(f, c, label="CO 1-%d" % (ch + 1))
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legend = ax.legend(loc='lower right', shadow=True, fontsize='small')
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plt.xlabel('frequency [Hz]')
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plt.ylabel('Coherence')
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plt.show()
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