ParamGroupScheduler#

class ignite.handlers.param_scheduler.ParamGroupScheduler(schedulers, names=None, save_history=False)[source]#

Scheduler helper to group multiple schedulers into one.

Parameters

schedulers (List[ParamScheduler]) – list/tuple of parameter schedulers.
names (Optional[List[str]]) – list of names of schedulers.
save_history (bool) – whether to save history or not.

optimizer = SGD(
    [
        {"params": model.base.parameters(), 'lr': 0.001),
        {"params": model.fc.parameters(), 'lr': 0.01),
    ]
)

scheduler1 = LinearCyclicalScheduler(optimizer, 'lr', 1e-7, 1e-5, len(train_loader), param_group_index=0)
scheduler2 = CosineAnnealingScheduler(optimizer, 'lr', 1e-5, 1e-3, len(train_loader), param_group_index=1)
lr_schedulers = [scheduler1, scheduler2]
names = ["lr (base)", "lr (fc)"]

scheduler = ParamGroupScheduler(schedulers=lr_schedulers, names=names)
# Attach single scheduler to the trainer
trainer.add_event_handler(Events.ITERATION_STARTED, scheduler)

New in version 0.4.5.

Methods

`load_state_dict`	Copies parameters from `state_dict` into this ParamScheduler.
`simulate_values`	Method to simulate scheduled values during num_events events.
`state_dict`	Returns a dictionary containing a whole state of ParamGroupScheduler.

load_state_dict(state_dict)[source]#

Copies parameters from state_dict into this ParamScheduler.

Parameters: state_dict (Mapping) – a dict containing parameters.
Return type: None

classmethod simulate_values(num_events, schedulers, **kwargs)[source]#

Method to simulate scheduled values during num_events events.

Parameters

num_events (int) – number of events during the simulation.
schedulers (List[_LRScheduler]) – lr_scheduler object to wrap.
kwargs (Any) – kwargs passed to construct an instance of ignite.handlers.param_scheduler.ParamGroupScheduler.

Returns

event_index, value

Return type

List[List[int]]

state_dict()[source]#

Returns a dictionary containing a whole state of ParamGroupScheduler.

Returns: a dictionary containing a whole state of ParamGroupScheduler
Return type: dict