# Distributed under terms of the MIT license. """ =============================== Gabor Representation of a Chirp =============================== Figure 3.11 from the tutorial. """ from tftb.generators import fmlin from tftb.processing.linear import gabor import matplotlib.pyplot as plt import numpy as np N1 = 256 Ng = 33 Q = 1 sig = fmlin(N1)[0] window = np.exp(np.log(0.005) * np.linspace(-1, 1, Ng)**2) window = window / np.linalg.norm(window) tfr, dgr, h = gabor(sig, 16, Q, window) plt.imshow(np.flipud(tfr)[8:, :], aspect='auto', extent=[0, 16, 0, 0.5], interpolation='none') plt.xlabel('Time') plt.ylabel('Normalized frequency') plt.title('Squared modulus of the Gabor coefficients') plt.show()
# # Copyright © 2015 jaidev <jaidev@newton> # # Distributed under terms of the MIT license. """ ============================= Biorthonormal Window Function ============================= """ from tftb.generators import fmlin from tftb.processing.linear import gabor import matplotlib.pyplot as plt import numpy as np N1 = 256 Ng = 33 Q = 1 sig = fmlin(N1)[0] window = np.exp(np.log(0.005) * np.linspace(-1, 1, Ng) ** 2) window = window / np.linalg.norm(window) tfr, dgr, h = gabor(sig, 16, Q, window) plt.plot(h) plt.ylim(top=0.5) plt.xlim(right=255) plt.title('Biorthonormal Window') plt.grid() plt.show()
# vim:fenc=utf-8 # # Copyright © 2015 jaidev <jaidev@newton> # # Distributed under terms of the MIT license. """ Example from section 3.3.2 of the tutorial. """ from tftb.generators import fmlin from tftb.processing.linear import gabor import matplotlib.pyplot as plt import numpy as np N1 = 256 Ng = 33 Q = 4 sig = fmlin(N1)[0] window = np.exp(np.log(0.005) * np.linspace(-1, 1, Ng) ** 2) window = window / np.linalg.norm(window) tfr, dgr, h = gabor(sig, 32, Q, window) time = np.arange(256) freq = np.linspace(0, 0.5, 128) plt.imshow(np.flipud(tfr)[8:, :], aspect='auto', extent=[0, 32, 0, 0.5], interpolation='none') plt.xlabel('Time') plt.ylabel('Normalized frequency') plt.title('Squared modulus of the Gabor coefficients') plt.show()