optuna.integration.ChainerPruningExtension
- class optuna.integration.ChainerPruningExtension(trial, observation_key, pruner_trigger)[source]
Chainer extension to prune unpromising trials.
See the example if you want to add a pruning extension which observes validation accuracy of a Chainer Trainer.
- Parameters
trial (Trial) – A
Trial
corresponding to the current evaluation of the objective function.observation_key (str) – An evaluation metric for pruning, e.g.,
main/loss
andvalidation/main/accuracy
. Please refer to chainer.Reporter reference for further details.pruner_trigger (Union[Tuple[int, str], IntervalTrigger, ManualScheduleTrigger]) –
A trigger to execute pruning.
pruner_trigger
is an instance of IntervalTrigger or ManualScheduleTrigger. IntervalTrigger can be specified by a tuple of the interval length and its unit like(1, 'epoch')
.