o
    Zhs                     @   sf   d dl Z d dl mZmZ d dlmZmZ d dlmZ d dlm	Z	 d dl
mZ dgZG dd de	ZdS )	    N)infTensor)Categoricalconstraints)Binomial)Distribution)broadcast_allMultinomialc                       s   e Zd ZU dZejejdZee	d< e
defddZe
defddZd! fdd	Zd" fdd	Zdd Zejdd	ddd Ze
defddZe
defddZe
dejfddZe fddZdd Zdd  Z  ZS )#r	   a`  
    Creates a Multinomial distribution parameterized by :attr:`total_count` and
    either :attr:`probs` or :attr:`logits` (but not both). The innermost dimension of
    :attr:`probs` indexes over categories. All other dimensions index over batches.

    Note that :attr:`total_count` need not be specified if only :meth:`log_prob` is
    called (see example below)

    .. note:: The `probs` argument must be non-negative, finite and have a non-zero sum,
              and it will be normalized to sum to 1 along the last dimension. :attr:`probs`
              will return this normalized value.
              The `logits` argument will be interpreted as unnormalized log probabilities
              and can therefore be any real number. It will likewise be normalized so that
              the resulting probabilities sum to 1 along the last dimension. :attr:`logits`
              will return this normalized value.

    -   :meth:`sample` requires a single shared `total_count` for all
        parameters and samples.
    -   :meth:`log_prob` allows different `total_count` for each parameter and
        sample.

    Example::

        >>> # xdoctest: +SKIP("FIXME: found invalid values")
        >>> m = Multinomial(100, torch.tensor([ 1., 1., 1., 1.]))
        >>> x = m.sample()  # equal probability of 0, 1, 2, 3
        tensor([ 21.,  24.,  30.,  25.])

        >>> Multinomial(probs=torch.tensor([1., 1., 1., 1.])).log_prob(x)
        tensor([-4.1338])

    Args:
        total_count (int): number of trials
        probs (Tensor): event probabilities
        logits (Tensor): event log probabilities (unnormalized)
    probslogitstotal_countreturnc                 C   s   | j | j S N)r   r   self r   N/var/www/auris/lib/python3.10/site-packages/torch/distributions/multinomial.pymean6      zMultinomial.meanc                 C   s   | j | j d| j  S )N   r   r   r   r   r   r   variance:   s   zMultinomial.variancer   Nc                    sd   t |ts	td|| _t||d| _t|| jd| _| jj	}| jj
dd  }t j|||d d S )Nz*inhomogeneous total_count is not supportedr
   r   validate_args)
isinstanceintNotImplementedErrorr   r   _categoricalr   r   	_binomialbatch_shapeparam_shapesuper__init__)r   r   r   r   r   r!   event_shape	__class__r   r   r$   >   s   
zMultinomial.__init__c                    sP   |  t|}t|}| j|_| j||_tt|j|| j	dd | j
|_
|S )NFr   )Z_get_checked_instancer	   torchSizer   r   expandr#   r$   r%   _validate_args)r   r!   Z	_instancenewr&   r   r   r*   H   s   

zMultinomial.expandc                 O   s   | j j|i |S r   )r   _new)r   argskwargsr   r   r   r-   S   s   zMultinomial._newT)Zis_discreteZ	event_dimc                 C   s   t | jS r   )r   Zmultinomialr   r   r   r   r   supportV   r   zMultinomial.supportc                 C      | j jS r   )r   r   r   r   r   r   r   Z      zMultinomial.logitsc                 C   r1   r   )r   r   r   r   r   r   r   ^   r2   zMultinomial.probsc                 C   r1   r   )r   r"   r   r   r   r   r"   b   r2   zMultinomial.param_shapec                 C   s   t |}| jt | jf| }tt| }||	d |j
| }|| | }|d|t | || jS )Nr   r   )r(   r)   r   sampler   listrangedimappendpopZpermuter,   Z_extended_shapeZzero_Zscatter_add_Z	ones_likeZtype_asr   )r   Zsample_shapeZsamplesZshifted_idxcountsr   r   r   r3   f   s   

zMultinomial.samplec                 C   s|   t | j}| j }|| t |d  }| jjdddd  }t | j	|}t |d }|| 
ddg}|| S )Nr   F)r*   r   r   )r(   Ztensorr   r   entropylgammar    Zenumerate_supportexplog_probsum)r   nZcat_entropyZterm1r0   Zbinomial_probsweightsZterm2r   r   r   r:   t   s   
zMultinomial.entropyc                 C   s   | j r| | t| j|\}}|jtjd}t|dd }t|d d}d||dk|t	 k@ < || d}|| | S )N)Zmemory_formatr   r   r   )
r+   Z_validate_sampler   r   cloner(   Zcontiguous_formatr;   r>   r   )r   valuer   Zlog_factorial_nZlog_factorial_xsZ
log_powersr   r   r   r=      s   
zMultinomial.log_prob)r   NNNr   )__name__
__module____qualname____doc__r   ZsimplexZreal_vectorZarg_constraintsr   __annotations__propertyr   r   r   r$   r*   r-   Zdependent_propertyr0   r   r   r(   r)   r"   r3   r:   r=   __classcell__r   r   r&   r   r	      s,   
 %

)r(   r   r   Ztorch.distributionsr   r   Ztorch.distributions.binomialr   Z torch.distributions.distributionr   Ztorch.distributions.utilsr   __all__r	   r   r   r   r   <module>   s   