import matplotlib.pyplot as plt
from thinkdsp import decorate
from thinkdsp import TriangleSignal
def filter_spectrum(spectrum):
"""Divides the spectrum through by the fs.
spectrum: Spectrum object
"""
# avoid division by 0
spectrum.hs[1:] /= spectrum.fs[1:]
spectrum.hs[0] =0
wave = TriangleSignal(freq=440).make_wave(duration=0.5)
wave.make_audio()
spectrum = wave.make_spectrum()
spectrum.plot(high=10000, color='gray')
filter_spectrum(spectrum)
spectrum.scale(440)
spectrum.plot(high=10000)
decorate(xlabel='Frequency (Hz)')
filtered = spectrum.make_wave()
filtered.make_audio()
wave.write(filename='6.9.3.wav')
plt.show()
spectrum.hs[1:] /= spectrum.fs[1:]
spectrum.hs[0] = 0
def play(file, flags):
print('Now play ' + file)
PlaySound(file, flags)
print('end')
trangle = TriangleSignal(freq=440).make_wave(duration=0.01, framerate=10000)
plt.subplot(231)
plt.title("trangle")
trangle.plot()
trangle.write("三角波声音.wav")
play("三角波声音.wav", flags=1)
square = SquareSignal(freq=440).make_wave(duration=0.01, framerate=10000)
plt.subplot(232)
plt.title("square")
square.plot()
square.write("方波声音.wav")
play("方波声音.wav", flags=1)
sawtooth = SawtoothSignal(freq=440).make_wave(duration=0.01, framerate=10000)
plt.subplot(233)
plt.title("sawtooth")
sawtooth.plot()
sawtooth.write("斜波声音.wav")
play("斜波声音.wav", flags=1)
spectrum_tra = trangle.make_spectrum()