o
    yi                     @   s>   d dl Z d dl mZmZ d dlmZ dededefddZdS )	    N)Tensortensor)"_check_retrieval_functional_inputspredstargetreturnc                 C   s\   t | |\} }| std| jdS |tj| ddd }t|d}d|d d  }|S )az  Computes reciprocal rank (for information retrieval). See `Mean Reciprocal Rank`_

    ``preds`` and ``target`` should be of the same shape and live on the same device. If no ``target`` is ``True``,
    0 is returned. ``target`` must be either `bool` or `integers` and ``preds`` must be ``float``,
    otherwise an error is raised.

    Args:
        preds: estimated probabilities of each document to be relevant.
        target: ground truth about each document being relevant or not.

    Return:
        a single-value tensor with the reciprocal rank (RR) of the predictions ``preds`` wrt the labels ``target``.

    Example:
        >>> from torchmetrics.functional import retrieval_reciprocal_rank
        >>> preds = torch.tensor([0.2, 0.3, 0.5])
        >>> target = torch.tensor([False, True, False])
        >>> retrieval_reciprocal_rank(preds, target)
        tensor(0.5000)
    g        )deviceT)dim
descendingg      ?r   )r   sumr   r   torchargsortnonzeroview)r   r   positionres r   e/home/ubuntu/.local/lib/python3.10/site-packages/torchmetrics/functional/retrieval/reciprocal_rank.pyretrieval_reciprocal_rank   s   r   )r   r   r   torchmetrics.utilities.checksr   r   r   r   r   r   <module>   s   