U
    ¯Ê¹jÏ  ã                   @   s4   d Z ddlZddlZddlmZ G dd„ deƒZdS )zë Adan Optimizer

Adan: Adaptive Nesterov Momentum Algorithm for Faster Optimizing Deep Models[J]. arXiv preprint arXiv:2208.06677, 2022.
    https://arxiv.org/abs/2208.06677

Implementation adapted from https://github.com/sail-sg/Adan
é    N)Ú	Optimizerc                       sD   e Zd ZdZd‡ fdd„	Ze ¡ d	d
„ ƒZe ¡ ddd„ƒZ‡  Z	S )ÚAdanae  
    Implements a pytorch variant of Adan
    Adan was proposed in
    Adan: Adaptive Nesterov Momentum Algorithm for Faster Optimizing Deep Models[J]. arXiv preprint arXiv:2208.06677, 2022.
    https://arxiv.org/abs/2208.06677
    Arguments:
        params (iterable): iterable of parameters to optimize or dicts defining parameter groups.
        lr (float, optional): learning rate. (default: 1e-3)
        betas (Tuple[float, float, flot], optional): coefficients used for computing
            running averages of gradient and its norm. (default: (0.98, 0.92, 0.99))
        eps (float, optional): term added to the denominator to improve
            numerical stability. (default: 1e-8)
        weight_decay (float, optional): decoupled weight decay (L2 penalty) (default: 0)
        no_prox (bool): how to perform the decoupled weight decay (default: False)
    çü©ñÒMbP?©g\�Âõ(\ï?gq=
×£pí?g®Gáz®ï?ç:Œ0âŽyE>ç        Fc                    sØ   d|kst d |¡ƒ‚d|ks,t d |¡ƒ‚d|d   krDdk sXn t d |d ¡ƒ‚d|d   krpdk s„n t d |d ¡ƒ‚d|d	   krœdk s°n t d
 |d	 ¡ƒ‚t|||||d�}tt| ƒ ||¡ d S )Nr   zInvalid learning rate: {}zInvalid epsilon value: {}r   ç      ð?z%Invalid beta parameter at index 0: {}é   z%Invalid beta parameter at index 1: {}é   z%Invalid beta parameter at index 2: {})ÚlrÚbetasÚepsÚweight_decayÚno_prox)Ú
ValueErrorÚformatÚdictÚsuperr   Ú__init__)ÚselfÚparamsr   r   r   r   r   Údefaults©Ú	__class__© úN/var/www/html/bwave/python/venv/lib/python3.8/site-packages/timm/optim/adan.pyr   !   s    	zAdan.__init__c                 C   s`   | j D ]T}d|d< |d D ]>}|jr| j| }t |¡|d< t |¡|d< t |¡|d< qqd S )Nr   Ústepr   Úexp_avgÚ
exp_avg_sqÚexp_avg_diff)Úparam_groupsZrequires_gradÚstateÚtorchÚ
zeros_like)r   ÚgroupÚpr!   r   r   r   Úrestart_opt7   s    

zAdan.restart_optNc              	   C   s$  d}|dk	r&t  ¡ � |ƒ }W 5 Q R X | jD �]ð}|d \}}}d|krZ|d  d7  < nd|d< d||d   }d||d   }d||d   }	|d D �]€}
|
jdkr¬qš|
j}| j|
 }t|ƒdkrþt  |
¡|d< t  |
¡|d	< t  |
¡|d
< | ¡ |d< |d |d	 |d
   }}}||d  }| |d| ¡ | |d| ¡ |||  }| 	|¡j
||d| d� | ¡ t |	¡  |d ¡}|| || |   |¡}|d �rÞ|
j 	d|d |d   ¡ |
j||d  d� n0|
j||d  d� |
j d|d |d   ¡ |d  |¡ qšq,|S )z. Performs a single optimization step.
        Nr   r   r	   r   r   r   r   r   r   Zpre_grad)Úvaluer   r   r   r   )Úalpha)r"   Zenable_gradr    Úgradr!   Úlenr#   ÚcloneZlerp_Zmul_Zaddcmul_ÚsqrtÚmathZadd_Zdiv_ÚdataZcopy_)r   ÚclosureZlossr$   Zbeta1Zbeta2Zbeta3Zbias_correction1Zbias_correction2Zbias_correction3r%   r)   r!   r   r   r   Z	grad_diffÚupdateÚdenomr   r   r   r   G   sJ    



z	Adan.step)r   r   r   r   F)N)
Ú__name__Ú
__module__Ú__qualname__Ú__doc__r   r"   Zno_gradr&   r   Ú__classcell__r   r   r   r   r      s        ù
r   )r5   r-   r"   Ztorch.optimr   r   r   r   r   r   Ú<module>   s   