EarlyStopping¶
- class lightning.pytorch.callbacks.EarlyStopping(monitor, min_delta=0.0, patience=3, verbose=False, mode='min', strict=True, check_finite=True, stopping_threshold=None, divergence_threshold=None, check_on_train_epoch_end=None, log_rank_zero_only=False)[source]¶
Bases:
lightning.pytorch.callbacks.callback.Callback
Monitor a metric and stop training when it stops improving.
- Parameters
min_delta¶ (
float
) – minimum change in the monitored quantity to qualify as an improvement, i.e. an absolute change of less than or equal to min_delta, will count as no improvement.number of checks with no improvement after which training will be stopped. Under the default configuration, one check happens after every training epoch. However, the frequency of validation can be modified by setting various parameters on the
Trainer
, for examplecheck_val_every_n_epoch
andval_check_interval
.Note
It must be noted that the patience parameter counts the number of validation checks with no improvement, and not the number of training epochs. Therefore, with parameters
check_val_every_n_epoch=10
andpatience=3
, the trainer will perform at least 40 training epochs before being stopped.mode¶ (
str
) – one of'min'
,'max'
. In'min'
mode, training will stop when the quantity monitored has stopped decreasing and in'max'
mode it will stop when the quantity monitored has stopped increasing.strict¶ (
bool
) – whether to crash the training if monitor is not found in the validation metrics.check_finite¶ (
bool
) – When setTrue
, stops training when the monitor becomes NaN or infinite.stopping_threshold¶ (
Optional
[float
]) – Stop training immediately once the monitored quantity reaches this threshold.divergence_threshold¶ (
Optional
[float
]) – Stop training as soon as the monitored quantity becomes worse than this threshold.check_on_train_epoch_end¶ (
Optional
[bool
]) – whether to run early stopping at the end of the training epoch. If this isFalse
, then the check runs at the end of the validation.log_rank_zero_only¶ (
bool
) – When setTrue
, logs the status of the early stopping callback only for rank 0 process.
- Raises
MisconfigurationException – If
mode
is none of"min"
or"max"
.RuntimeError – If the metric
monitor
is not available.
Example:
>>> from lightning.pytorch import Trainer >>> from lightning.pytorch.callbacks import EarlyStopping >>> early_stopping = EarlyStopping('val_loss') >>> trainer = Trainer(callbacks=[early_stopping])
Tip
Saving and restoring multiple early stopping callbacks at the same time is supported under variation in the following arguments:
monitor, mode
Read more: Persisting Callback State
- load_state_dict(state_dict)[source]¶
Called when loading a checkpoint, implement to reload callback state given callback’s
state_dict
.
- on_train_epoch_end(trainer, pl_module)[source]¶
Called when the train epoch ends.
To access all batch outputs at the end of the epoch, you can cache step outputs as an attribute of the
pytorch_lightning.LightningModule
and access them in this hook:class MyLightningModule(L.LightningModule): def __init__(self): super().__init__() self.training_step_outputs = [] def training_step(self): loss = ... self.training_step_outputs.append(loss) return loss class MyCallback(L.Callback): def on_train_epoch_end(self, trainer, pl_module): # do something with all training_step outputs, for example: epoch_mean = torch.stack(pl_module.training_step_outputs).mean() pl_module.log("training_epoch_mean", epoch_mean) # free up the memory pl_module.training_step_outputs.clear()
- Return type
- setup(trainer, pl_module, stage)[source]¶
Called when fit, validate, test, predict, or tune begins.
- Return type
- property state_key: str¶
Identifier for the state of the callback.
Used to store and retrieve a callback’s state from the checkpoint dictionary by
checkpoint["callbacks"][state_key]
. Implementations of a callback need to provide a unique state key if 1) the callback has state and 2) it is desired to maintain the state of multiple instances of that callback.- Return type