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Source code for torch_uncertainty.metrics.classification.categorical_nll

from typing import Any, Literal

import torch
import torch.nn.functional as F
from torch import Tensor
from torchmetrics import Metric
from torchmetrics.utilities.data import dim_zero_cat


[docs]class CategoricalNLL(Metric): is_differentiable = False higher_is_better = False full_state_update = False def __init__( self, reduction: Literal["mean", "sum", "none", None] = "mean", **kwargs: Any, ) -> None: """The Negative Log Likelihood Metric. Args: reduction (str, optional): Determines how to reduce over the :math:`B`/batch dimension: - ``'mean'`` [default]: Averages score across samples - ``'sum'``: Sum score across samples - ``'none'`` or ``None``: Returns score per sample kwargs: Additional keyword arguments, see `Advanced metric settings <https://torchmetrics.readthedocs.io/en/stable/pages/overview.html#metric-kwargs>`_. Inputs: - :attr:`probs`: :math:`(B, C)` - :attr:`target`: :math:`(B)` where :math:`B` is the batch size and :math:`C` is the number of classes. Warning: Make sure that the probabilities in :attr:`probs` are normalized to sum to one. Raises: ValueError: If :attr:`reduction` is not one of ``'mean'``, ``'sum'``, ``'none'`` or ``None``. """ super().__init__(**kwargs) allowed_reduction = ("sum", "mean", "none", None) if reduction not in allowed_reduction: raise ValueError( "Expected argument `reduction` to be one of ", f"{allowed_reduction} but got {reduction}", ) self.reduction = reduction if self.reduction in ["mean", "sum"]: self.add_state( "values", default=torch.tensor(0.0), dist_reduce_fx="sum", ) else: self.add_state("values", default=[], dist_reduce_fx="cat") self.add_state("total", default=torch.tensor(0), dist_reduce_fx="sum")
[docs] def update(self, probs: Tensor, target: Tensor) -> None: """Update state with prediction probabilities and targets. Args: probs (Tensor): Probabilities from the model. target (Tensor): Ground truth labels. """ if self.reduction is None or self.reduction == "none": self.values.append( F.nll_loss(torch.log(probs), target, reduction="none") ) else: self.values += F.nll_loss(torch.log(probs), target, reduction="sum") self.total += target.size(0)
[docs] def compute(self) -> Tensor: """Computes NLL based on inputs passed in to ``update`` previously.""" values = dim_zero_cat(self.values) if self.reduction == "sum": return values.sum(dim=-1) if self.reduction == "mean": return values.sum(dim=-1) / self.total # reduction is None or "none" return values