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Z
 ddlmZ d	d
lmZ G dd„ deƒZdS )é    )Úannotations)ÚAnyN)Ú_Loss)Údo_metric_reduction)ÚMetricReductioné   )ÚTensorOrListé   )ÚCumulativeIterationMetricc                      sD   e Zd ZdZejdfd‡ fdd„Z	dddd„Zdddd„Z‡  Z	S )Ú
LossMetrica¯  
    A wrapper to make ``loss_fn`` available as a cumulative metric. That is, the loss values computed from
    mini-batches can be combined in the ``reduction`` mode across multiple iterations, as a quantitative measurement
    of a model.

    Example:

    .. code-block:: python

        import torch
        from monai.losses import DiceLoss
        from monai.metrics import LossMetric

        dice_loss = DiceLoss(include_background=True)
        loss_metric = LossMetric(loss_fn=dice_loss)

        # first iteration
        y_pred = torch.tensor([[[[1.0, 0.0], [0.0, 1.0]]]])  # shape [batch=1, channel=1, 2, 2]
        y = torch.tensor([[[[1.0, 0.0], [1.0, 1.0]]]])  # shape [batch=1, channel=1, 2, 2]
        loss_metric(y_pred, y)

        # second iteration
        y_pred = torch.tensor([[[[1.0, 0.0], [0.0, 0.0]]]])  # shape [batch=1, channel=1, 2, 2]
        y = torch.tensor([[[[1.0, 0.0], [1.0, 1.0]]]])  # shape [batch=1, channel=1, 2, 2]
        loss_metric(y_pred, y)

        # aggregate
        print(loss_metric.aggregate(reduction="none"))  # tensor([[0.2000], [0.5000]]) (shape [batch=2, channel=1])

        # reset
        loss_metric.reset()
        print(loss_metric.aggregate())


    Args:
        loss_fn: a callable function that takes ``y_pred`` and optionally ``y`` as input (in the "batch-first" format),
            returns a "batch-first" tensor of loss values.
        reduction: define mode of reduction to the metrics, will only apply reduction on `not-nan` values,
            available reduction modes: {``"none"``, ``"mean"``, ``"sum"``, ``"mean_batch"``, ``"sum_batch"``,
            ``"mean_channel"``, ``"sum_channel"``}, default to ``"mean"``. if "none", will not do reduction.
        get_not_nans: whether to return the `not_nans` count, if True, aggregate() returns (metric, not_nans).
            Here `not_nans` count the number of not nans for the metric, thus its shape equals to the shape of the metric.

    FÚloss_fnr   Ú	reductionúMetricReduction | strÚget_not_nansÚboolÚreturnÚNonec                   s    t ƒ  ¡  || _|| _|| _d S ©N)ÚsuperÚ__init__r   r   r   )Úselfr   r   r   ©Ú	__class__© ú[/home/dell461/cl/sdc2/last_ska_mid/HISourceFinder-master-l/src/monai/metrics/loss_metric.pyr   H   s   

zLossMetric.__init__NúMetricReduction | str | Noneú0torch.Tensor | tuple[torch.Tensor, torch.Tensor]c                 C  sZ   |   ¡ }|du r| jrt d¡t d¡fS t d¡S t||p | jƒ\}}| jr+||fS |S )a¶  
        Returns the aggregated loss value across multiple iterations.

        Args:
            reduction: define mode of reduction to the metrics, will only apply reduction on `not-nan` values,
                available reduction modes: {``"none"``, ``"mean"``, ``"sum"``, ``"mean_batch"``, ``"sum_batch"``,
                ``"mean_channel"``, ``"sum_channel"``}, default to `self.reduction`. if "none", will not do reduction.
        Ng        )Ú
get_bufferr   ÚtorchÚtensorr   r   )r   r   ÚdataÚfÚnot_nansr   r   r   Ú	aggregateP   s
   $zLossMetric.aggregateÚy_predútorch.TensorÚyútorch.Tensor | NoneÚkwargsr   r   c                 K  sN   |du r	|   |¡n|   ||¡}t|tjƒr%| ¡ dk r%|d }| ¡ dk s|S )a	  
        Input `y_pred` is compared with ground truth `y`.
        Both `y_pred` and `y` are expected to be a batch-first Tensor (BC[HWD]).

        Returns:
             a tensor with shape (BC[HWD]), or a list of tensors, each tensor with shape (C[HWD]).
        Nr   )r   Ú
isinstancer   ÚTensorÚdim)r   r$   r&   r(   Z	iter_lossr   r   r   Ú_compute_tensora   s   ÿzLossMetric._compute_tensor)r   r   r   r   r   r   r   r   r   )r   r   r   r   )r$   r%   r&   r'   r(   r   r   r   )
Ú__name__Ú
__module__Ú__qualname__Ú__doc__r   ÚMEANr   r#   r,   Ú__classcell__r   r   r   r   r      s    .ÿ	ÿr   )Ú
__future__r   Útypingr   r   Útorch.nn.modules.lossr   Úmonai.metrics.utilsr   Úmonai.utilsr   Úconfigr   Úmetricr
   r   r   r   r   r   Ú<module>   s   