TYPESCRIPT

subplots legend

ax1.plot(xtr, color='r', label='HHZ 1')
ax1.legend(loc="upper right")
ax2.plot(xtr, color='r', label='HHN')
ax2.legend(loc="upper right")
ax3.plot(xtr, color='r', label='HHE')
ax3.legend(loc="upper right")

subplots legend

f, (ax1, ax2, ax3) = plt.subplots(3, sharex=True, sharey=True)
l1,=ax1.plot(x,y, color='r', label='Blue stars')
l2,=ax2.plot(x,y, color='g')
l3,=ax3.plot(x,y, color='b')
ax1.set_title('2012/09/15')
plt.legend([l1, l2, l3],["HHZ 1", "HHN", "HHE"])
plt.show()