def output_monitor(self):
        matplotlib.rcParams.update({'font.size': 36})
        sz = 500
        x = np.linspace(-1.2, 0.6, sz)
        y = np.linspace(-0.07, 0.07, sz)
        xx, yy = np.meshgrid(x, y)
        states = np.stack((xx.reshape(-1), yy.reshape(-1)), 1)
        action_values = self.get_action_values(states)
        vmin = np.min(action_values)
        vmax = np.max(action_values)

        fig, axes = plt.subplots(figsize=(34, 7), nrows=1, ncols=3, sharey=True)
        for t in range(self.num_actions):
            axes[t].xaxis.set_tick_params(width=2, length=8)
            axes[t].xaxis.set_ticks(np.array([-1.0, -0.5, 0.0, 0.5]))
            if t == 0:
                axes[t].yaxis.set_tick_params(width=2, length=8)
                axes[t].yaxis.set_ticks(np.array([-0.5, 0.0, 0.5]))
            if t == 0:
                axes[t].set_title("Go to the left".format(t), y=1.05)
            if t == 1:
                axes[t].set_title("Do nothing".format(t), y=1.05)
            if t == 2:
                axes[t].set_title("Go to the right".format(t), y=1.05)

            mp = axes[t].imshow(action_values[:, t].reshape(sz, sz),
                                extent=(-1.2, 0.6, 0.7, -0.7),
                                interpolation='nearest', vmin=vmin-0.1,
                                vmax=vmax+0.1)
            axes[t].set_xlabel('position')
            axes[0].set_ylabel('velosity * 10')
        fig.subplots_adjust(right=0.8)
        cbar_ax = fig.add_axes([0.85, -0.01, 0.04, 1.0])
        cbar_ax.xaxis.set_tick_params(width=2, length=8)
        cbar_ax.yaxis.set_tick_params(width=2, length=8)
        fig.colorbar(mp, cax=cbar_ax)
        plt.show()