下面的此功能可查找频谱。我还提供了一个正弦信号和一个WAV文件示例应用程序。这是出于教育目的；您也可以使用易于使用的matplotlib.pyplot.magnitude_spectrum（请参见下文）。
from scipy import fft, arangeimport numpy as npimport matplotlib.pyplot as pltfrom scipy.io import wavfileimport osdef frequency_sepectrum(x, sf): """ Derive frequency spectrum of a signal from time domain :param x: signal in the time domain :param sf: sampling frequency :returns frequencies and their content distribution """ x = x - np.average(x) # zero-centering n = len(x) print(n) k = arange(n) tarr = n / float(sf) frqarr = k / float(tarr) # two sides frequency range frqarr = frqarr[range(n // 2)] # one side frequency range x = fft(x) / n # fft computing and normalization x = x[range(n // 2)] return frqarr, abs(x)# Sine sample with a frequency of 1hz and add some noisesr = 32 # sampling ratey = np.linspace(0, 2*np.pi, sr)y = np.tile(np.sin(y), 5)y += np.random.normal(0, 1, y.shape)t = np.arange(len(y)) / float(sr)plt.subplot(2, 1, 1)plt.plot(t, y)plt.xlabel('t')plt.ylabel('y')frq, X = frequency_sepectrum(y, sr)plt.subplot(2, 1, 2)plt.plot(frq, X, 'b')plt.xlabel('Freq (Hz)')plt.ylabel('|X(freq)|')plt.tight_layout()# wav sample from https://freewavesamples.com/files/Alesis-Sanctuary-QCard-Crickets.wavhere_path = os.path.dirname(os.path.realpath(__file__))wav_file_name = 'Alesis-Sanctuary-QCard-Crickets.wav'wave_file_path = os.path.join(here_path, wav_file_name)sr, signal = wavfile.read(wave_file_path)y = signal[:, 0] # use the first channel (or take their average, alternatively)t = np.arange(len(y)) / float(sr)plt.figure()plt.subplot(2, 1, 1)plt.plot(t, y)plt.xlabel('t')plt.ylabel('y')frq, X = frequency_sepectrum(y, sr)plt.subplot(2, 1, 2)plt.plot(frq, X, 'b')plt.xlabel('Freq (Hz)')plt.ylabel('|X(freq)|')plt.tight_layout()plt.show()您还可以参考SciPy的Fourier变换和Matplotlib的幅度谱绘图页面以获取更多信息和功能。
magspec = plt.magnitude_spectrum(y, sr) # returns a tuple with the frequencies and associated magnitudes
