Time-frequency Resolution: Short Analysis Window

This example shows the effect of an analysis window which is short in time on the time-frequency resolution. Specifically, smaller windows have good time resolutions but poor frequency resolutions.

Figure 3.8 from the tutorial.

import numpy as np
import matplotlib.pyplot as plt
from tftb.generators import atoms
from scipy.signal import hamming
from tftb.processing.linear import ShortTimeFourierTransform

coords = np.array([[45, .25, 32, 1], [85, .25, 32, 1]])
sig = atoms(128, coords)
x = np.real(sig)
window = hamming(17)
stft = ShortTimeFourierTransform(sig, n_fbins=128, fwindow=window)
stft.run()
stft.plot(show_tf=True, cmap=plt.cm.gray)