How can I use Python to plot the Fast Fourier Transform (FFT) of a signal?

Answer 1

To plot the Fast Fourier Transform (FFT) of a signal using Python, you can use the numpy library to compute the FFT and the matplotlib library to plot the results. First, import the necessary libraries:

python import numpy as np import matplotlib.pyplot as plt

Next, generate a sample signal and its corresponding time values:

python Generate a sample signal fs 1000 Sampling frequency t np.arange(0, 1, 1/fs) Time values signal np.sin(2 np.pi 50 t) 0.5 np.sin(2 np.pi 120 t) Example signal

Then, compute the FFT of the signal using np.fft.fft:

python fftresult np.fft.fft(signal) freqs np.fft.fftfreq(len(signal), 1/fs)

Finally, plot the FFT magnitude spectrum using plt.plot:

python plt.figure() plt.plot(freqs:len(freqs)//2, np.abs(fftresult):len(freqs)//2) plt.xlabel('Frequency (Hz)') plt.ylabel('Magnitude') plt.title('FFT of Signal') plt.show()

This code snippet demonstrates how to use Python to plot the FFT of a signal.