
    קg                     `    d dl mZ d dlZd dlmZ d dlmZ d dlmZ dgZ	 G d de          Z
dS )    )NumberN)constraints)ExponentialFamily)broadcast_allPoissonc                        e Zd ZdZdej        iZej        Ze	d             Z
e	d             Ze	d             Zd fd	Zd fd	Z ej                    fd	Zd
 Ze	d             Zd Z xZS )r   a  
    Creates a Poisson distribution parameterized by :attr:`rate`, the rate parameter.

    Samples are nonnegative integers, with a pmf given by

    .. math::
      \mathrm{rate}^k \frac{e^{-\mathrm{rate}}}{k!}

    Example::

        >>> # xdoctest: +SKIP("poisson_cpu not implemented for 'Long'")
        >>> m = Poisson(torch.tensor([4]))
        >>> m.sample()
        tensor([ 3.])

    Args:
        rate (Number, Tensor): the rate parameter
    ratec                     | j         S Nr	   selfs    W/var/www/html/ai-engine/env/lib/python3.11/site-packages/torch/distributions/poisson.pymeanzPoisson.mean#   
    y    c                 4    | j                                         S r   )r	   floorr   s    r   modezPoisson.mode'   s    y   r   c                     | j         S r   r   r   s    r   variancezPoisson.variance+   r   r   Nc                     t          |          \  | _        t          |t                    rt	          j                    }n| j                                        }t                                          ||           d S )Nvalidate_args)	r   r	   
isinstancer   torchSizesizesuper__init__)r   r	   r   batch_shape	__class__s       r   r    zPoisson.__init__/   sg    $T**dF## 	+*,,KK)..**KMBBBBBr   c                    |                      t          |          }t          j        |          }| j                            |          |_        t          t          |                              |d           | j        |_        |S )NFr   )	_get_checked_instancer   r   r   r	   expandr   r    _validate_args)r   r!   	_instancenewr"   s       r   r%   zPoisson.expand7   sq    (()<<j--9##K00gs$$[$FFF!0
r   c                     |                      |          }t          j                    5  t          j        | j                            |                    cd d d            S # 1 swxY w Y   d S r   )_extended_shaper   no_gradpoissonr	   r%   )r   sample_shapeshapes      r   samplezPoisson.sample?   s    $$\22]__ 	: 	:=!1!1%!8!899	: 	: 	: 	: 	: 	: 	: 	: 	: 	: 	: 	: 	: 	: 	: 	: 	: 	:s   ,A""A&)A&c                     | j         r|                     |           t          | j        |          \  }}|                    |          |z
  |dz                                   z
  S )N   )r&   _validate_sampler   r	   xlogylgamma)r   valuer	   s      r   log_probzPoisson.log_probD   sb     	)!!%(((#DIu55e{{4  4'519*<*<*>*>>>r   c                 6    t          j        | j                  fS r   )r   logr	   r   s    r   _natural_paramszPoisson._natural_paramsJ   s    	$)$$&&r   c                 *    t          j        |          S r   )r   exp)r   xs     r   _log_normalizerzPoisson._log_normalizerN   s    y||r   r   )__name__
__module____qualname____doc__r   nonnegativearg_constraintsnonnegative_integersupportpropertyr   r   r   r    r%   r   r   r/   r6   r9   r=   __classcell__)r"   s   @r   r   r      s+        $ {67O-G  X ! ! X!   XC C C C C C      #-%*,, : : : :
? ? ? ' ' X'      r   )numbersr   r   torch.distributionsr   torch.distributions.exp_familyr   torch.distributions.utilsr   __all__r    r   r   <module>rN      s           + + + + + + < < < < < < 3 3 3 3 3 3 +B B B B B B B B B Br   