pypots/optim/adam.py
"""
The optimizer wrapper for PyTorch Adam.
"""
# Created by Wenjie Du <wenjay.du@gmail.com>
# License: BSD-3-Clause
from typing import Iterable, Tuple, Optional
from torch.optim import Adam as torch_Adam
from .base import Optimizer
from .lr_scheduler.base import LRScheduler
class Adam(Optimizer):
"""The optimizer wrapper for PyTorch Adam :class:`torch.optim.Adam`.
Parameters
----------
lr : float
The learning rate of the optimizer.
betas : Tuple[float, float]
Coefficients used for computing running averages of gradient and its square.
eps : float
Term added to the denominator to improve numerical stability.
weight_decay : float
Weight decay (L2 penalty).
amsgrad : bool
Whether to use the AMSGrad variant of this algorithm from the paper :cite:`reddi2018OnTheConvergence`.
lr_scheduler : pypots.optim.lr_scheduler.base.LRScheduler
The learning rate scheduler of the optimizer.
"""
def __init__(
self,
lr: float = 0.001,
betas: Tuple[float, float] = (0.9, 0.999),
eps: float = 1e-08,
weight_decay: float = 0,
amsgrad: bool = False,
lr_scheduler: Optional[LRScheduler] = None,
):
super().__init__(lr, lr_scheduler)
self.betas = betas
self.eps = eps
self.weight_decay = weight_decay
self.amsgrad = amsgrad
def init_optimizer(self, params: Iterable) -> None:
"""Initialize the torch optimizer wrapped by this class.
Parameters
----------
params :
An iterable of ``torch.Tensor`` or ``dict``. Specifies what Tensors should be optimized.
"""
self.torch_optimizer = torch_Adam(
params=params,
lr=self.lr,
betas=self.betas,
eps=self.eps,
weight_decay=self.weight_decay,
amsgrad=self.amsgrad,
)
if self.lr_scheduler is not None:
self.lr_scheduler.init_scheduler(self.torch_optimizer)