One-way pAUC — pAUCLoss (1w) + SOPAs
======================================

Optimizes partial AUC restricted to a specific FPR range ``[0, max_fpr]``.
Useful when false positives are costly and sensitivity at low FPR is the
primary concern.

Config
------

.. code-block:: yaml
   :caption: recipes/config_opauc.yaml

   dataset:
     name: cifar10
     eval_splits: [val, test]
     kwargs:
       imratio: 0.02

   model:
     name: resnet18
     pretrained: false
     num_classes: 1
     in_channels: 3

   metrics:
     - AUROC
   metric_kwargs:
     - max_fpr: 0.3

   training:
     project_name: libauc
     experiment_name: resnet18_opauc_cifar10
     SEED: 2026
     epochs: 60
     batch_size: 128
     eval_batch_size: 256
     sampling_rate: 0.5
     num_workers: 0
     decay_epochs: [0.5, 0.75]
     loss: pAUCLoss
     loss_kwargs:
       mode: 1w
     optimizer: SOPAs
     output_path: ./output
     resume_from_checkpoint: false
     save_checkpoint_every: 5

   automax:
     deterministic: true
     n_trials: 5
     SEED: 42
     name: resnet18_opauc_cifar10
     output_directory: ./automax_output
     overwrite: true

Run
---

.. code-block:: bash

   python -m src.auto_trainer \
     --config_file recipes/config_opauc.yaml

.. note::

   The ``max_fpr`` value in ``metric_kwargs`` controls which region of the
   ROC curve is optimized. A value of ``0.3`` means only the area under
   the curve for FPR ∈ [0, 0.3] is maximized.