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Source code for catalyst.callbacks.optimizer

from typing import Callable, Dict, TYPE_CHECKING, Union
from functools import partial

from catalyst.core.callback import IOptimizerCallback
from catalyst.registry import REGISTRY
from catalyst.utils.misc import get_attr
from catalyst.utils.torch import get_optimizer_momentum_list

if TYPE_CHECKING:
    from catalyst.core.runner import IRunner


[docs]class OptimizerCallback(IOptimizerCallback): """Optimizer callback, abstraction over optimizer step. Args: metric_key: a key to get loss from ``runner.batch_metrics`` model_key: a key to select a model from ``runner.model`` in case there are several of them and they are in a dictionary format. optimizer_key: a key to select a optimizer from ``runner.optimizer`` in case there are several of them and they are in a dictionary format. accumulation_steps: number of steps before ``optimizer.step()`` grad_clip_fn: callable gradient cliping function or it's name or grad_clip_params: key-value parameters for grad_clip_fn .. note:: Please follow the `minimal examples`_ sections for more use cases. .. _`minimal examples`: https://github.com/catalyst-team/catalyst#minimal-examples # noqa: E501, W505 """ def __init__( self, metric_key: str, optimizer_key: str = None, accumulation_steps: int = 1, grad_clip_fn: Union[str, Callable] = None, grad_clip_params: Dict = None, ): """Init.""" super().__init__() self.metric_key = metric_key self.optimizer_key = optimizer_key self.optimizer = None self.criterion = None if isinstance(grad_clip_fn, str): self.grad_clip_fn = REGISTRY.get(grad_clip_fn) else: self.grad_clip_fn = grad_clip_fn if grad_clip_params is not None: self.grad_clip_fn = partial(self.grad_clip_fn, **grad_clip_params) self.accumulation_steps: int = accumulation_steps self._accumulation_counter: int = 0 if self.optimizer_key is not None: self._prefix = f"{self.optimizer_key}" self._prefix_lr = f"lr/{self._prefix}" self._prefix_momentum = f"momentum/{self._prefix}" self._prefix_gradient = f"gradient/{self._prefix}" else: self._prefix_lr = "lr" self._prefix_momentum = "momentum" self._prefix_gradient = "gradient" def _get_lr_momentum_stats(self) -> Dict: lr_list = [param_group["lr"] for param_group in self.optimizer.param_groups] momentum_list = get_optimizer_momentum_list(self.optimizer) stats = {self._prefix_lr: lr_list[0], self._prefix_momentum: momentum_list[0]} return stats def on_experiment_start(self, runner: "IRunner") -> None: """Event handler.""" self.optimizer = get_attr(runner, key="optimizer", inner_key=self.optimizer_key) assert self.optimizer is not None def on_batch_end(self, runner: "IRunner"): """Event handler.""" if runner.is_train_loader: self._accumulation_counter += 1 need_gradient_step = ( self._accumulation_counter % self.accumulation_steps == 0 ) if need_gradient_step: self.optimizer.step() self.optimizer.zero_grad() runner.batch_metrics.update(self._get_lr_momentum_stats()) def on_loader_end(self, runner: "IRunner") -> None: """Event handler.""" runner.loader_metrics.update(self._get_lr_momentum_stats())
__all__ = ["OptimizerCallback"]