// off xtick labels on all but the lower plot
f = plt.figure()
plt.subplots_adjust(hspace=0.001)
ax1 = plt.subplot(311)
After Change
// Plot each graph, and manually set the y tick values
axs[0].plot(t, s1)
axs[0].set_yticks(np.arange(-0.9, 1.0, 0.4))
axs[0].set_ylim(-1, 1)
axs[1].plot(t, s2)
axs[1].set_yticks(np.arange(0.1, 1.0, 0.2))
axs[1].set_ylim(0, 1)