square_fourier.py

"""
Animation of Fourier series square-wave.

author: Austin Schaller
email: schaller.austin@gmail.com
license: None
"""

import numpy as np
import matplotlib.pyplot as plt
from matplotlib import animation
import seaborn as sns; sns.set()


w0 = 2*np.pi
fig = plt.figure()
ax = plt.axes(xlim=(0,2), ylim=(-2,2))
line, = ax.plot([], [], lw=2)


# initialization
def init():
	line.set_data([], [])
	return line,

# animation function, called sequentially
def animate(i):
	x = np.linspace(0, 10, 10000)
	y = np.sin(w0*x)
	for j in range(3, i + 1):
		if j % 2 == True:
			y += np.sin(w0*j*x)/j
	line.set_data(x, y)
	return line,

# call the animator
anim = animation.FuncAnimation(fig, animate, init_func=init, frames=150, interval=30, blit=True)
plt.title('Fourier Series Square-wave')
plt.xlabel('Time (s)')
plt.ylabel('Amplitude (V)')
plt.show()