Update yaml configs

xautodl/xmisc/scheduler_utils.py

@@ -0,0 +1,136 @@
+#####################################################
+# Copyright (c) Xuanyi Dong [GitHub D-X-Y], 2021.06 #
+#####################################################
+from torch.optim.lr_scheduler import _LRScheduler
+
+
+class CosineDecayWithWarmup(_LRScheduler):
+    r"""Set the learning rate of each parameter group using a cosine annealing
+    schedule, where :math:`\eta_{max}` is set to the initial lr, :math:`T_{cur}`
+    is the number of epochs since the last restart and :math:`T_{i}` is the number
+    of epochs between two warm restarts in SGDR:
+    .. math::
+        \eta_t = \eta_{min} + \frac{1}{2}(\eta_{max} - \eta_{min})\left(1 +
+        \cos\left(\frac{T_{cur}}{T_{i}}\pi\right)\right)
+    When :math:`T_{cur}=T_{i}`, set :math:`\eta_t = \eta_{min}`.
+    When :math:`T_{cur}=0` after restart, set :math:`\eta_t=\eta_{max}`.
+    It has been proposed in
+    `SGDR: Stochastic Gradient Descent with Warm Restarts`_.
+    Args:
+        optimizer (Optimizer): Wrapped optimizer.
+        T_0 (int): Number of iterations for the first restart.
+        T_mult (int, optional): A factor increases :math:`T_{i}` after a restart. Default: 1.
+        eta_min (float, optional): Minimum learning rate. Default: 0.
+        last_epoch (int, optional): The index of last epoch. Default: -1.
+        verbose (bool): If ``True``, prints a message to stdout for
+            each update. Default: ``False``.
+    .. _SGDR\: Stochastic Gradient Descent with Warm Restarts:
+        https://arxiv.org/abs/1608.03983
+    """
+
+    def __init__(
+        self, optimizer, T_0, T_mult=1, eta_min=0, last_epoch=-1, verbose=False
+    ):
+        if T_0 <= 0 or not isinstance(T_0, int):
+            raise ValueError("Expected positive integer T_0, but got {}".format(T_0))
+        if T_mult < 1 or not isinstance(T_mult, int):
+            raise ValueError("Expected integer T_mult >= 1, but got {}".format(T_mult))
+        self.T_0 = T_0
+        self.T_i = T_0
+        self.T_mult = T_mult
+        self.eta_min = eta_min
+
+        super(CosineDecayWithWarmup, self).__init__(optimizer, last_epoch, verbose)
+
+        self.T_cur = self.last_epoch
+
+    def get_lr(self):
+        if not self._get_lr_called_within_step:
+            warnings.warn(
+                "To get the last learning rate computed by the scheduler, "
+                "please use `get_last_lr()`.",
+                UserWarning,
+            )
+
+        return [
+            self.eta_min
+            + (base_lr - self.eta_min)
+            * (1 + math.cos(math.pi * self.T_cur / self.T_i))
+            / 2
+            for base_lr in self.base_lrs
+        ]
+
+    def step(self, epoch=None):
+        """Step could be called after every batch update
+        Example:
+            >>> scheduler = CosineDecayWithWarmup(optimizer, T_0, T_mult)
+            >>> iters = len(dataloader)
+            >>> for epoch in range(20):
+            >>>     for i, sample in enumerate(dataloader):
+            >>>         inputs, labels = sample['inputs'], sample['labels']
+            >>>         optimizer.zero_grad()
+            >>>         outputs = net(inputs)
+            >>>         loss = criterion(outputs, labels)
+            >>>         loss.backward()
+            >>>         optimizer.step()
+            >>>         scheduler.step(epoch + i / iters)
+        This function can be called in an interleaved way.
+        Example:
+            >>> scheduler = CosineDecayWithWarmup(optimizer, T_0, T_mult)
+            >>> for epoch in range(20):
+            >>>     scheduler.step()
+            >>> scheduler.step(26)
+            >>> scheduler.step() # scheduler.step(27), instead of scheduler(20)
+        """
+
+        if epoch is None and self.last_epoch < 0:
+            epoch = 0
+
+        if epoch is None:
+            epoch = self.last_epoch + 1
+            self.T_cur = self.T_cur + 1
+            if self.T_cur >= self.T_i:
+                self.T_cur = self.T_cur - self.T_i
+                self.T_i = self.T_i * self.T_mult
+        else:
+            if epoch < 0:
+                raise ValueError(
+                    "Expected non-negative epoch, but got {}".format(epoch)
+                )
+            if epoch >= self.T_0:
+                if self.T_mult == 1:
+                    self.T_cur = epoch % self.T_0
+                else:
+                    n = int(
+                        math.log(
+                            (epoch / self.T_0 * (self.T_mult - 1) + 1), self.T_mult
+                        )
+                    )
+                    self.T_cur = epoch - self.T_0 * (self.T_mult ** n - 1) / (
+                        self.T_mult - 1
+                    )
+                    self.T_i = self.T_0 * self.T_mult ** (n)
+            else:
+                self.T_i = self.T_0
+                self.T_cur = epoch
+        self.last_epoch = math.floor(epoch)
+
+        class _enable_get_lr_call:
+            def __init__(self, o):
+                self.o = o
+
+            def __enter__(self):
+                self.o._get_lr_called_within_step = True
+                return self
+
+            def __exit__(self, type, value, traceback):
+                self.o._get_lr_called_within_step = False
+                return self
+
+        with _enable_get_lr_call(self):
+            for i, data in enumerate(zip(self.optimizer.param_groups, self.get_lr())):
+                param_group, lr = data
+                param_group["lr"] = lr
+                self.print_lr(self.verbose, i, lr, epoch)
+
+        self._last_lr = [group["lr"] for group in self.optimizer.param_groups]