class, compare, trigger=(1, 'epoch'))[source]

Trigger invoked when specific value becomes best.

  • key (str) – Key of value.
  • compare (callable) – Compare function which takes current best value and new value and returns whether new value is better than current best.
  • trigger – Trigger that decides the comparison interval between current best value and new value. This must be a tuple in the form of <int>, 'epoch' or <int>, 'iteration' which is passed to IntervalTrigger.



Decides whether the extension should be called on this iteration.

Parameters:trainer (Trainer) – Trainer object that this trigger is associated with. The observation of this trainer is used to determine if the trigger should fire.
Returns:True if the corresponding extension should be invoked in this iteration.
Return type:bool