PiecewiseLinear#
- class ignite.handlers.param_scheduler.PiecewiseLinear(optimizer, param_name, milestones_values, save_history=False, param_group_index=None)[source]#
Piecewise linear parameter scheduler
- Parameters
optimizer (Optimizer) – torch optimizer or any object with attribute
param_groupsas a sequence.param_name (str) – name of optimizer’s parameter to update.
milestones_values (List[Tuple[int, float]]) – list of tuples (event index, parameter value) represents milestones and parameter. Milestones should be increasing integers.
save_history (bool) – whether to log the parameter values to engine.state.param_history, (default=False).
param_group_index (Optional[int]) – optimizer’s parameters group to use.
scheduler = PiecewiseLinear(optimizer, "lr", milestones_values=[(10, 0.5), (20, 0.45), (21, 0.3), (30, 0.1), (40, 0.1)]) # Attach to the trainer trainer.add_event_handler(Events.ITERATION_STARTED, scheduler) # # Sets the learning rate to 0.5 over the first 10 iterations, then decreases linearly from 0.5 to 0.45 between # 10th and 20th iterations. Next there is a jump to 0.3 at the 21st iteration and LR decreases linearly # from 0.3 to 0.1 between 21st and 30th iterations and remains 0.1 until the end of the iterations. #
New in version 0.4.5.
Methods
Method to get current optimizer's parameter values