Source code for torch_uncertainty.losses.regression
from typing import Literal
import torch
from torch import Tensor, nn
from torch.distributions import Distribution
from torch_uncertainty.utils.distributions import NormalInverseGamma
[docs]class DistributionNLLLoss(nn.Module):
def __init__(self, reduction: Literal["mean", "sum"] | None = "mean") -> None:
"""Negative Log-Likelihood loss using given distributions as inputs.
Args:
reduction (str, optional): specifies the reduction to apply to the
output:``'none'`` | ``'mean'`` | ``'sum'``. Defaults to "mean".
"""
super().__init__()
self.reduction = reduction
[docs] def forward(
self,
dist: Distribution,
targets: Tensor,
padding_mask: Tensor | None = None,
) -> Tensor:
"""Compute the NLL of the targets given predicted distributions.
Args:
dist (Distribution): The predicted distributions
targets (Tensor): The target values
padding_mask (Tensor, optional): The padding mask. Defaults to None.
Sets the loss to 0 for padded values.
"""
loss = -dist.log_prob(targets)
if padding_mask is not None:
loss = loss.masked_fill(padding_mask, 0.0)
if self.reduction == "mean":
loss = loss.mean()
elif self.reduction == "sum":
loss = loss.sum()
return loss
[docs]class DERLoss(DistributionNLLLoss):
def __init__(self, reg_weight: float, reduction: str | None = "mean") -> None:
"""The Deep Evidential Regression loss.
This loss combines the negative log-likelihood loss of the normal
inverse gamma distribution and a weighted regularization term.
Args:
reg_weight (float): The weight of the regularization term.
reduction (str, optional): specifies the reduction to apply to the
output:``'none'`` | ``'mean'`` | ``'sum'``.
Reference:
Amini, A., Schwarting, W., Soleimany, A., & Rus, D. (2019). Deep
evidential regression. https://arxiv.org/abs/1910.02600.
"""
super().__init__(reduction=None)
if reduction not in ("none", "mean", "sum") and reduction is not None:
raise ValueError(f"{reduction} is not a valid value for reduction.")
self.der_reduction = reduction
if reg_weight < 0:
raise ValueError(
"The regularization weight should be non-negative, but got " f"{reg_weight}."
)
self.reg_weight = reg_weight
def _reg(self, dist: NormalInverseGamma, targets: Tensor) -> Tensor:
return torch.norm(targets - dist.loc, 1, dim=1, keepdim=True) * (
2 * dist.lmbda + dist.alpha
)
def forward(
self,
dist: NormalInverseGamma,
targets: Tensor,
) -> Tensor:
loss_nll = super().forward(dist, targets)
loss_reg = self._reg(dist, targets)
loss = loss_nll + self.reg_weight * loss_reg
if self.der_reduction == "mean":
return loss.mean()
if self.der_reduction == "sum":
return loss.sum()
return loss
[docs]class BetaNLL(nn.Module):
def __init__(self, beta: float = 0.5, reduction: str | None = "mean") -> None:
"""The Beta Negative Log-likelihood loss.
Args:
beta (float): TParameter from range [0, 1] controlling relative
weighting between data points, where `0` corresponds to
high weight on low error points and `1` to an equal weighting.
reduction (str, optional): specifies the reduction to apply to the
output:``'none'`` | ``'mean'`` | ``'sum'``.
Reference:
Seitzer, M., Tavakoli, A., Antic, D., & Martius, G. (2022). On the
pitfalls of heteroscedastic uncertainty estimation with probabilistic
neural networks. https://arxiv.org/abs/2203.09168.
"""
super().__init__()
if beta < 0 or beta > 1:
raise ValueError("The beta parameter should be in range [0, 1], but got " f"{beta}.")
self.beta = beta
self.nll_loss = nn.GaussianNLLLoss(reduction="none")
if reduction not in ("none", "mean", "sum"):
raise ValueError(f"{reduction} is not a valid value for reduction.")
self.reduction = reduction
def forward(self, mean: Tensor, targets: Tensor, variance: Tensor) -> Tensor:
loss = self.nll_loss(mean, targets, variance) * (variance.detach() ** self.beta)
if self.reduction == "mean":
return loss.mean()
if self.reduction == "sum":
return loss.sum()
return loss