Source code for emerging_optimizers.soap.rekls

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# SPDX-License-Identifier: Apache-2.0
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# Licensed under the Apache License, Version 2.0 (the "License");
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# http://www.apache.org/licenses/LICENSE-2.0
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from torch.optim.optimizer import ParamsT

from emerging_optimizers import mixin as opt_mixin
from emerging_optimizers import registry
from emerging_optimizers.soap.soap import SOAP


__all__ = ["REKLS"]




@registry.register_optimizer("rekls")
class REKLS(SOAP):
    """REKLS (Realtime Eigen Kullback-Leibler Soap) optimizer.

    REKLS is a variant of SOAP that uses the up to date eigenbasis calculated by Eigen decomposition. It is
    "up to date" because current step's gradient is accumulated to the kronecker factor before eigenbasis update.

    Note:
        Refer to :class:`~emerging_optimizers.soap.soap.SOAP` for detailed documentation of arguments.
    """

    def __init__(
        self,
        params: ParamsT,
        lr: float,
        betas: tuple[float, float] = (0.9, 0.95),
        shampoo_beta: float = 0.95,
        eps: float = 1e-8,
        weight_decay: float = 0.01,
        *,
        weight_decay_method: opt_mixin.WeightDecayT = "decoupled",
    ) -> None:
        super().__init__(
            params,
            lr,
            betas,
            shampoo_beta,
            eps,
            weight_decay,
            weight_decay_method=weight_decay_method,
            use_eigh=True,
            use_kl_shampoo=True,
        )