backward

allennlp.training.callbacks.backward

[SOURCE]

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MixedPrecisionBackwardCallback

@TrainerCallback.register("mixed_precision_backward")
class MixedPrecisionBackwardCallback(TrainerCallback)

Performs backpropagation for mixed precision training.

on_backward

class MixedPrecisionBackwardCallback(TrainerCallback):
 | ...
 | def on_backward(
 |     self,
 |     trainer: "GradientDescentTrainer",
 |     batch_outputs: Dict[str, torch.Tensor],
 |     backward_called: bool,
 |     **kwargs
 | ) -> bool

OnBackwardException

class OnBackwardException(Exception):
 | def __init__(self, message="") -> None

The exception type raised if an on_backward callback attempts to call backward when backward_called is True.