o
    yi                     @   s   d dl mZ d dlZd dlmZ d dlmZ 	ddededed	eeef fd
dZdeded	efddZ	deded	efddZ
dS )    )TupleN)Tensor)_check_same_shape-`>predstargetepsilonreturnc                 C   sJ   t | | t| | }|tjt||d }t|}| }||fS )ad  Updates and returns variables required to compute Mean Percentage Error.

    Checks for same shape of input tensors.

    Args:
        preds: Predicted tensor
        target: Ground truth tensor
        epsilon: Specifies the lower bound for target values. Any target value below epsilon
            is set to epsilon (avoids ``ZeroDivisionError``).
    )min)r   torchabsclampsumnumel)r   r   r   abs_diffabs_per_errorsum_abs_per_errornum_obs r   [/home/ubuntu/.local/lib/python3.10/site-packages/torchmetrics/functional/regression/mape.py&_mean_absolute_percentage_error_update   s   

r   r   r   c                 C   s   | | S )aF  Computes Mean Absolute Percentage Error.

    Args:
        sum_abs_per_error: Sum of absolute value of percentage errors over all observations
            ``(percentage error = (target - prediction) / target)``
        num_obs: Number of predictions or observations

    Example:
        >>> target = torch.tensor([1, 10, 1e6])
        >>> preds = torch.tensor([0.9, 15, 1.2e6])
        >>> sum_abs_per_error, num_obs = _mean_absolute_percentage_error_update(preds, target)
        >>> _mean_absolute_percentage_error_compute(sum_abs_per_error, num_obs)
        tensor(0.2667)
    r   )r   r   r   r   r   '_mean_absolute_percentage_error_compute2   s   r   c                 C   s   t | |\}}t||}|S )a  Computes mean absolute percentage error.

    Args:
        preds: estimated labels
        target: ground truth labels

    Return:
        Tensor with MAPE

    Note:
        The epsilon value is taken from `scikit-learn's implementation of MAPE`_.

    Example:
        >>> from torchmetrics.functional import mean_absolute_percentage_error
        >>> target = torch.tensor([1, 10, 1e6])
        >>> preds = torch.tensor([0.9, 15, 1.2e6])
        >>> mean_absolute_percentage_error(preds, target)
        tensor(0.2667)
    )r   r   )r   r   r   r   mean_aper   r   r   mean_absolute_percentage_errorE   s   
r   )r   )typingr   r   r   torchmetrics.utilities.checksr   floatintr   r   r   r   r   r   r   <module>   s    

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