#! /usr/bin/env python
# -*- coding: utf-8 -*-
# vim:fenc=utf-8
#
# Copyright © 2015 jaidev <jaidev@newton>
#
# Distributed under terms of the MIT license.

"""
====================================================
Distant Chirps with a Short Gaussian Analysis Window
====================================================

Figure 3.17 from the tutorial.
"""

from tftb.generators import fmlin
from tftb.processing.cohen import Spectrogram
import numpy as np
import matplotlib.pyplot as plt

sig = fmlin(128, 0, 0.3)[0] + fmlin(128, 0.2, 0.5)[0]
window = np.exp(np.log(0.005) * np.linspace(-1, 1, 23) ** 2)
spec = Spectrogram(sig, fwindow=window, n_fbins=128)
spec.run()
spec.plot(show_tf=True, cmap=plt.cm.gray)