x' mode or best * ( 1 - threshold ) in `min` mode. In `abs` mode, dynamic_threshold = best + threshold in `max` mode or best - threshold in `min` mode. Default: 'rel'. cooldown (int): Number of epochs to wait before resuming normal operation after lr has been reduced. Default: 0. min_lr (float or list): A scalar or a list of scalars. A lower bound on the learning rate of all param groups or each group respectively. Default: 0. eps (float): Minimal decay applied to lr. If the difference between new and old lr is smaller than eps, the update is ignored. Default: 1e-8. verbose (bool): If ``True``, prints a message to stdout for each update. Default: ``False``. Example: >>> # xdoctest: +SKIP >>> optimizer = torch.optim.SGD(model.parameters(), lr=0.1, momentum=0.9) >>> scheduler = ReduceLROnPlateau(optimizer, 'min') >>> for epoch in range(10): >>> train(...) >>> val_loss = validate(...) >>> # Note that step should be called after validate() >>> scheduler.step(val_loss) rĪ