o
    yi	                  	   @   sT   d dl mZ d dlZd dlmZmZ d dlmZ ddededee defd	d
ZdS )    )OptionalN)Tensortensor)"_check_retrieval_functional_inputspredstargetkreturnc                 C   s   t | |\} }|du r| jd }t|tr|dkstd| s(td| jdS |tj	| ddd d|  
 }||  S )	a  Computes the recall metric (for information retrieval). Recall is the fraction of relevant documents
    retrieved among all the relevant documents.

    ``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. If you want to measure Recall@K, ``k`` must be a positive integer.

    Args:
        preds: estimated probabilities of each document to be relevant.
        target: ground truth about each document being relevant or not.
        k: consider only the top k elements (default: `None`, which considers them all)

    Returns:
        a single-value tensor with the recall (at ``k``) of the predictions ``preds`` w.r.t. the labels ``target``.

    Raises:
        ValueError:
            If ``k`` parameter is not `None` or an integer larger than 0

    Example:
        >>> from  torchmetrics.functional import retrieval_recall
        >>> preds = tensor([0.2, 0.3, 0.5])
        >>> target = tensor([True, False, True])
        >>> retrieval_recall(preds, target, k=2)
        tensor(0.5000)
    Nr   z(`k` has to be a positive integer or Noneg        )deviceT)dim
descending)r   shape
isinstanceint
ValueErrorsumr   r   torchargsortfloat)r   r   r   relevant r   \/home/ubuntu/.local/lib/python3.10/site-packages/torchmetrics/functional/retrieval/recall.pyretrieval_recall   s   
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