Python metrics.Metric方法代码示例

# 需要导入模块: from ignite import metrics [as 别名]
# 或者: from ignite.metrics import Metric [as 别名]
def __init__(self, src=None, alpha=0.98, output_transform=None):
        if not (isinstance(src, Metric) or src is None):
            raise TypeError("Argument src should be a Metric or None.")
        if not (0.0 < alpha <= 1.0):
            raise ValueError("Argument alpha should be a float between 0.0 and 1.0.")

        if isinstance(src, Metric):
            if output_transform is not None:
                raise ValueError("Argument output_transform should be None if src is a Metric.")
            self.src = src
            self._get_src_value = self._get_metric_value
            self.iteration_completed = self._metric_iteration_completed
        else:
            if output_transform is None:
                raise ValueError("Argument output_transform should not be None if src corresponds "
                                 "to the output of process function.")
            self._get_src_value = self._get_output_value
            self.update = self._output_update

        self.alpha = alpha
        super(RunningAverage, self).__init__(output_transform=output_transform) 

# 需要导入模块: from ignite import metrics [as 别名]
# 或者: from ignite.metrics import Metric [as 别名]
def __init__(self, metric: Metric):
        self.source_metric = metric
        self.reset()

        super().__init__(lambda x: x[:-1]) 

# 需要导入模块: from ignite import metrics [as 别名]
# 或者: from ignite.metrics import Metric [as 别名]
def update(self, output):

        if not isinstance(self.source_metric, MetricsLambda):
            self.source_metric.update(output)
            return

        # If a source metric is made of several metrics, e.g. MetricsLambda
        # metrics, we need to update each sub-metrics separately
        for source in self.source_metric.args:
            if isinstance(source, Metric):
                source.update(output)
        return 

# 需要导入模块: from ignite import metrics [as 别名]
# 或者: from ignite.metrics import Metric [as 别名]
def create_supervised_evaluator(
    model: torch.nn.Module,
    metrics: Optional[Dict[str, Metric]] = None,
    device: Optional[Union[str, torch.device]] = None,
    non_blocking: bool = False,
    prepare_batch: Callable = _prepare_batch,
    output_transform: Callable = lambda x, y, y_pred: (y_pred, y),
) -> Engine:
    """
    Factory function for creating an evaluator for supervised models.

    Args:
        model (`torch.nn.Module`): the model to train.
        metrics (dict of str - :class:`~ignite.metrics.Metric`): a map of metric names to Metrics.
        device (str, optional): device type specification (default: None).
            Applies to batches after starting the engine. Model *will not* be moved.
        non_blocking (bool, optional): if True and this copy is between CPU and GPU, the copy may occur asynchronously
            with respect to the host. For other cases, this argument has no effect.
        prepare_batch (callable, optional): function that receives `batch`, `device`, `non_blocking` and outputs
            tuple of tensors `(batch_x, batch_y)`.
        output_transform (callable, optional): function that receives 'x', 'y', 'y_pred' and returns value
            to be assigned to engine's state.output after each iteration. Default is returning `(y_pred, y,)` which fits
            output expected by metrics. If you change it you should use `output_transform` in metrics.

    Note:
        `engine.state.output` for this engine is defind by `output_transform` parameter and is
        a tuple of `(batch_pred, batch_y)` by default.

    .. warning::

        The internal use of `device` has changed.
        `device` will now *only* be used to move the input data to the correct device.
        The `model` should be moved by the user before creating an optimizer.

        For more information see:

        - `PyTorch Documentation <https://pytorch.org/docs/stable/optim.html#constructing-it>`_

        - `PyTorch's Explanation <https://github.com/pytorch/pytorch/issues/7844#issuecomment-503713840>`_

    Returns:
        Engine: an evaluator engine with supervised inference function.
    """
    metrics = metrics or {}

    def _inference(engine: Engine, batch: Sequence[torch.Tensor]) -> Union[Any, Tuple[torch.Tensor]]:
        model.eval()
        with torch.no_grad():
            x, y = prepare_batch(batch, device=device, non_blocking=non_blocking)
            y_pred = model(x)
            return output_transform(x, y, y_pred)

    evaluator = Engine(_inference)

    for name, metric in metrics.items():
        metric.attach(evaluator, name)

    return evaluator