import matplotlib.pyplot as plt
import numpy as np

t = np.arange(0.0, 2.0, 0.01)
s = 1 + np.sin(2 * np.pi * t)
plt.plot(t, s)

plt.xlabel('time(s)')
plt.ylabel('voltage(mV)')
plt.title('A nice sine wave')
plt.grid(True)
# plt.savefig('test.png')
plt.show()
