Access and change peval_mode for any strategy.

[ksandeshk]

Trying to change the peval_mode after some epochs.
Initially it is set to peval_mode="iteration" for few epochs and then want to change it to peval_mode="epoch".
Example strategy = Naive(..., eval_every=1, peval_mode="iteration")
But able to access the parameter value of strategy.eval_every and not able to access the peval_mode parameter value.
Kindly suggest how to access the value and change it in between epochs.

[ksandeshk]

One example solution which worked is by using the below plugin, which when included as one of the plugins to an avalanche strategy helps change the evaluation from iteration to epoch after 5 epochs of training. The code was suggested by Giacomo Cignoni (https://github.com/giacomo-cgn).

from avalanche.core import BaseSGDPlugin
from avalanche.training.templates.base_sgd import PeriodicEval

class MyPlugin(BaseSGDPlugin):
   def __init__(self):
       super().__init__()
       self.epoch_counter = 0
       self.switch_at_epoch = 5

   def after_training_epoch(self, strategy, **kwargs):
       self.epoch_counter += 1
       if self.epoch_counter == self.switch_at_epoch:
           # Switch peval_mode
           for plugin in strategy.plugins:
               # Itrate plugins to find PeriodicEval plugin
               if isinstance(plugin, PeriodicEval):
                   plugin.peval_mode = "iteration"
                   break