from math import *
import matplotlib.pyplot as plt
import numpy as np

phi=np.pi
t = np.linspace(0,10,1000)
y1 = np.cos(t)
y2 = 2*np.cos(t+phi)
y3 = y1+y2

plt.plot(t,y1,label='y1 (phi=0)')
plt.plot(t,y2,label='y2 (phi={0})'.format(phi))
plt.plot(t,y3,label='y1+y2')
plt.xlabel('t')
plt.ylabel('y')
plt.title('superposition de deux signaux sinusoidaux dephasés de {0}'.format(phi))
plt.legend()
plt.show()

Phi = [0,np.pi/2,np.pi,3*np.pi/2,2*np.pi]
Y1 = np.cos(t)


# for i in range(5):
#     y2 = 2*np.cos(t+Phi[i])
#     y3 = y1+y2
#     plt.plot(t,y3,label='y2 (phi={0})'.format(Phi[i]))
# plt.legend()
# plt.show()