I want to see the effect of a continuous drawing, with the following code(in python3):
fg = plt.figure()
ax = fg.add_subplot(1,1,1)
plt.ion()
for d in range(3):
    x_data = np.array([])
    y_data = np.array([])
    #plt.clf()
    for t in range(v):
        x = t
        x_data = np.append(x_data,x)
        y = t*d
        y_data = np.append(y_data,y)
    #ax.lines = ax.plot(x_data,y_data)
    plt.plot(x_data,y_data)
    #plt.show()
    #plt.pause(0.3)
    time.sleep(0.3)
plt.show()
plt.close('all')