o
    yii                     @   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jdt|d |jtjd|dk }t	tjt||jtjdd |
 }|S )	a  Computes average precision (for information retrieval), as explained in `IR Average precision`_.

    ``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 average precision (AP) of the predictions ``preds`` w.r.t. the labels ``target``.

    Example:
        >>> from torchmetrics.functional import retrieval_average_precision
        >>> preds = tensor([0.2, 0.3, 0.5])
        >>> target = tensor([True, False, True])
        >>> retrieval_average_precision(preds, target)
        tensor(0.8333)
    g        )deviceT)dim
descending   )r   dtyper   )r   sumr   r   torchargsortarangelenfloat32divmean)r   r   	positionsres r   g/home/ubuntu/.local/lib/python3.10/site-packages/torchmetrics/functional/retrieval/average_precision.pyretrieval_average_precision   s   &(r   )r   r   r   torchmetrics.utilities.checksr   r   r   r   r   r   <module>   s   