reaches to 1. Default: 5. last_epoch (int): The index of the last epoch. Default: -1. verbose (bool): If ``True``, prints a message to stdout for each update. Default: ``False``. Example: >>> # xdoctest: +SKIP >>> # Assuming optimizer uses lr = 0.05 for all groups >>> # lr = 0.025 if epoch == 0 >>> # lr = 0.03125 if epoch == 1 >>> # lr = 0.0375 if epoch == 2 >>> # lr = 0.04375 if epoch == 3 >>> # lr = 0.05 if epoch >= 4 >>> scheduler = LinearLR(self.opt, start_factor=0.5, total_iters=4) >>> for epoch in range(100): >>> train(...) >>> validate(...) >>> scheduler.step() r¿