I use Visdom vis.line() to draw the loss during training. But after a period of time, the loss window disappear in the env and not shown in the browser.
The loss draw function is as follows,
    def plot_current_losses(self, iter_id, losses, opt):
        """
        Plot losses in one figure current epoch
        Args:
            losses: dict
                {'loss_1': value, 'loss_2': value}
        """
        if not hasattr(self, 'plot_data'):
            self.plot_data = {'x': [], 'y': [], 'legend': list(losses.keys())}
        # @rivergold: Here is different from CycleGAN
        self.plot_data['x'].append(iter_id)
        self.plot_data['y'].append([losses[k]
                                    for k in self.plot_data['legend']])
        try:
            self.vis.line(
                # Here X shape is [n_losses, n_epoch]
                X=np.array(self.plot_data['x']),
                Y=np.array(self.plot_data['y']),
                opts={
                    'title': opt.name,
                    'legend': self.plot_data['legend'],
                    'xlabel': 'iter_id',
                    'ylabel': 'loss'},
                win=self.win_id,
                env=self.env
            )
        except ConnectionError:
            self._throw_visdom_connection_error()

There is no Error raised, but the loss window disappear…Why?