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

"""
=============================================
Wigner-Ville Distribution of a Doppler Signal
=============================================

This example shows the Wigner-Ville distribution of a Doppler signal. The
signal steadily rises and falls, but there are many interference terms present
in the time-friequency plane, due to the bilinearity of the signal.

Figure 4.2 from the tutorial.
"""

from tftb.generators import doppler
from tftb.processing import WignerVilleDistribution

fm, am, iflaw = doppler(256, 50.0, 13.0, 10.0, 200.0)
sig = am * fm
dist = WignerVilleDistribution(sig)
tfr, times, freqs = dist.run()
dist.plot(show_tf=True, kind="contour", scale="log")