o
    z“©ió  ã                   @   sN   d dl Z d dlZd dlmZ dd e jdfdd„Zddd	„Zd
d„ Zdd„ Z	dS )é    N)Únormé   Úcpuc                    s*   ddd„‰ ||f‡ ‡‡‡‡‡fdd„	}|S )	z+Ported from JAX. Ported from Yang Song repor   r   c                 S   s:   t  | ¡| |  | |  }| | | }| | | }||fS )N)ÚnpÚprod)ÚshapeÚin_axisÚout_axisÚreceptive_field_sizeÚfan_inÚfan_out© r   úL/home/ubuntu/.local/lib/python3.10/site-packages/score_models/definitions.pyÚ_compute_fans   s   z'variance_scaling.<locals>._compute_fansc                    s´   ˆ | ˆˆƒ\}}ˆdkr|}nˆdkr|}nˆdkr!|| d }nt d ˆ¡ƒ‚ˆ| }ˆdkr>tj| ||dœŽt |¡ S ˆdkrVtj| ||dœŽd	 d
 t d| ¡ S t dƒ‚)Nr   r   Úfan_avgé   z1invalid mode for variance scaling initializer: {}Únormal)ÚdtypeÚdeviceÚuniformg       @ç      ð?é   z5invalid distribution for variance scaling initializer)Ú
ValueErrorÚformatÚtorchÚrandnr   ÚsqrtÚrand)r   r   r   r   r   ÚdenominatorÚvariance©r   Údistributionr   Úmoder	   Úscaler   r   Úinit   s   (zvariance_scaling.<locals>.initN)r   r   r   )r#   r"   r!   r   r	   r   r   r$   r   r    r   Úvariance_scaling   s   
r%   r   c                 C   s   | dkrdn| } t | ddƒS )z%The same initialization used in DDPM.r   g»½×Ùß|Û=r   r   )r%   )r#   r   r   r   Údefault_init+   s   r&   c                    s.   |ˆ  d|  ‰t  ‡ ‡fdd„t|ƒD ƒ¡S )Nr   c                    s    g | ]}t  ˆ ˆ|  g¡‘qS r   )r   Útensor)Ú.0Ún©Úbegin_valueÚrr   r   Ú
<listcomp>3   s     z$geometric_series.<locals>.<listcomp>)r   ÚconcatÚrange)r+   Ú	end_valueÚLr   r*   r   Úgeometric_series1   s   r2   c                 C   s@   d| d }t  || d  d|   ¡t  || d  d|   ¡ S )zZ
    Technique 2 of Song & Ermon (2020) paper on improved techniques for training SBM
    r   g      à?r   r   )r   Úcdf)Úgammar)   Úcr   r   r   Úradial_acceptance_probability6   s   4r6   )r   )
r   Únumpyr   Úscipy.statsr   Úfloat32r%   r&   r2   r6   r   r   r   r   Ú<module>   s    
ù
%