o
    yiI                     @   sP   d dl mZ d dlZd dlmZ d dlmZmZ d dlmZ G dd deZ	dS )    )AnyN)Tensor)_log_cosh_error_compute_log_cosh_error_update)Metricc                       sr   e Zd ZU dZdZdZdZeed< eed< dde	de
d	d
f fddZdeded	d
fddZd	efddZ  ZS )LogCoshErrora8  Compute the `LogCosh Error`_.

    .. math:: \text{LogCoshError} = \log\left(\frac{\exp(\hat{y} - y) + \exp(\hat{y - y})}{2}\right)

    Where :math:`y` is a tensor of target values, and :math:`\hat{y}` is a tensor of predictions.

    As input to ``forward`` and ``update`` the metric accepts the following input:

    - ``preds`` (:class:`~torch.Tensor`): Estimated labels with shape ``(batch_size,)``
      or ``(batch_size, num_outputs)``
    - ``target`` (:class:`~torch.Tensor`): Ground truth labels with shape ``(batch_size,)``
      or ``(batch_size, num_outputs)``

    As output of ``forward`` and ``compute`` the metric returns the following output:

    - ``log_cosh_error`` (:class:`~torch.Tensor`): A tensor with the log cosh error

    Args:
        num_outputs: Number of outputs in multioutput setting
        kwargs: Additional keyword arguments, see :ref:`Metric kwargs` for more info.

    Example (single output regression)::
        >>> from torchmetrics import LogCoshError
        >>> preds = torch.tensor([3.0, 5.0, 2.5, 7.0])
        >>> target = torch.tensor([2.5, 5.0, 4.0, 8.0])
        >>> log_cosh_error = LogCoshError()
        >>> log_cosh_error(preds, target)
        tensor(0.3523)

    Example (multi output regression)::
        >>> from torchmetrics import LogCoshError
        >>> preds = torch.tensor([[3.0, 5.0, 1.2], [-2.1, 2.5, 7.0]])
        >>> target = torch.tensor([[2.5, 5.0, 1.3], [0.3, 4.0, 8.0]])
        >>> log_cosh_error = LogCoshError(num_outputs=3)
        >>> log_cosh_error(preds, target)
        tensor([0.9176, 0.4277, 0.2194])
    TFsum_log_cosh_errortotal   num_outputskwargsreturnNc                    sh   t  jdi | t|ts|dk rtd| || _| jdt|dd | jdt	ddd d S )	Nr
   zDExpected argument `num_outputs` to be an int larger than 0, but got r   sum)defaultdist_reduce_fxr	   r    )
super__init__
isinstanceint
ValueErrorr   	add_statetorchzerostensor)selfr   r   	__class__r   T/home/ubuntu/.local/lib/python3.10/site-packages/torchmetrics/regression/log_cosh.pyr   D   s   zLogCoshError.__init__predstargetc                 C   s2   t ||| j\}}|  j|7  _|  j|7  _dS )zUpdate state with predictions and targets.

        Raises:
            ValueError:
                If ``preds`` or ``target`` has multiple outputs when ``num_outputs=1``
        N)r   r   r   r	   )r   r   r    r   n_obsr   r   r   updateM   s   zLogCoshError.updatec                 C   s   t | j| jS )z!Compute LogCosh error over state.)r   r   r	   )r   r   r   r   computeX   s   zLogCoshError.compute)r
   )__name__
__module____qualname____doc__is_differentiablehigher_is_betterfull_state_updater   __annotations__r   r   r   r"   r#   __classcell__r   r   r   r   r      s   
 &	r   )
typingr   r   r   +torchmetrics.functional.regression.log_coshr   r   torchmetrics.metricr   r   r   r   r   r   <module>   s   