class ray.tune.stopper.TrialPlateauStopper(metric: str, std: float = 0.01, num_results: int = 4, grace_period: int = 4, metric_threshold: Optional[float] = None, mode: Optional[str] = None)[source]#

Bases: ray.tune.stopper.stopper.Stopper

Early stop single trials when they reached a plateau.

When the standard deviation of the metric result of a trial is below a threshold std, the trial plateaued and will be stopped early.

  • metric – Metric to check for convergence.

  • std – Maximum metric standard deviation to decide if a trial plateaued. Defaults to 0.01.

  • num_results – Number of results to consider for stdev calculation.

  • grace_period – Minimum number of timesteps before a trial can be early stopped

  • metric_threshold (Optional[float]) – Minimum or maximum value the result has to exceed before it can be stopped early.

  • mode – If a metric_threshold argument has been passed, this must be one of [min, max]. Specifies if we optimize for a large metric (max) or a small metric (min). If max, the metric_threshold has to be exceeded, if min the value has to be lower than metric_threshold in order to early stop.

PublicAPI: This API is stable across Ray releases.


Returns true if the experiment should be terminated.