from tftb.generators import fmlin
from tftb.processing.linear import ShortTimeFourierTransform
import matplotlib.pyplot as plt
from scipy.signal import hamming
import numpy as np
from mpl_toolkits.axes_grid1 import make_axes_locatable
N = 128
x1, _ = fmlin(N, 0, 0.2)
x2, _ = fmlin(N, 0.3, 0.5)
x = x1 + x2
n_fbins = 128
window = hamming(33)
tfr, _, _ = ShortTimeFourierTransform(x, timestamps=None, n_fbins=n_fbins,
fwindow=window).run()
tfr = tfr[:64, :]
threshold = np.amax(np.abs(tfr)) * 0.05
tfr[np.abs(tfr) <= threshold] = 0.0 + 1j * 0.0
tfr = np.abs(tfr) ** 2
t = np.arange(tfr.shape[1])
f = np.linspace(0, 0.5, tfr.shape[0])
T, F = np.meshgrid(t, f)
fig, axScatter = plt.subplots(figsize=(10, 8))
axScatter.contour(T, F, tfr, 5)
axScatter.grid(True)
axScatter.set_title('Squared modulus of STFT')
axScatter.set_ylabel('Frequency')
axScatter.yaxis.set_label_position("right")
#! /usr/bin/env python # -*- coding: utf-8 -*- # vim:fenc=utf-8 # # Copyright © 2015 jaidev <jaidev@newton> # # Distributed under terms of the MIT license. """ Example from section 3.1.4 of the tutorial. """ import numpy as np from tftb.processing.linear import ShortTimeFourierTransform from tftb.generators import fmlin, amgauss from matplotlib.pyplot import cm x = np.real(amgauss(128) * fmlin(128)[0]) window = np.array([1]) stft = ShortTimeFourierTransform(x, n_fbins=128, fwindow=window) tfr, _, _ = stft.run() stft.plot(show_tf=True, cmap=cm.gray)
from tftb.processing.linear import ShortTimeFourierTransform from tftb.generators import fmconst import numpy as np sig = np.r_[fmconst(128, 0.2)[0], fmconst(128, 0.4)[0]] tfr = ShortTimeFourierTransform(sig) tfr.run() tfr.plot()
