>>> """
=====================================
Plotting the coherence of two signals
=====================================

An example showing how to plot the coherence of two signals.
"""
... import numpy as np
... import matplotlib.pyplot as plt
... 
... # Fixing random state for reproducibility
... np.random.seed(19680801)
... 
... dt = 0.01
... t = np.arange(0, 30, dt)
... nse1 = np.random.randn(len(t))                 # white noise 1
... nse2 = np.random.randn(len(t))                 # white noise 2
... 
... # Two signals with a coherent part at 10Hz and a random part
... s1 = np.sin(2 * np.pi * 10 * t) + nse1
... s2 = np.sin(2 * np.pi * 10 * t) + nse2
... 
... fig, axs = plt.subplots(2, 1)
... axs[0].plot(t, s1, t, s2)
... axs[0].set_xlim(0, 2)
... axs[0].set_xlabel('time')
... axs[0].set_ylabel('s1 and s2')
... axs[0].grid(True)
... 
... cxy, f = axs[1].cohere(s1, s2, 256, 1. / dt)
... axs[1].set_ylabel('coherence')
... 
... fig.tight_layout()
... plt.show()
...