How metrics are computed?

[William9Baker]

When it comes to 'trainer.fit(model=model, datamodule=datamodule)', how does it automatically jump to this position that 'fpr, tpr = self._compute()' in the file of 'aupro.py'?

[samet-akcay]

@William9Baker, can you elaborate your question?

[samet-akcay]

model that we pass to Trainer is always a subclass of AnomalyModule that contains all these metric and threshold values as attributes, which are shown below:
https://github.com/openvinotoolkit/anomalib/blob/93239858c51de63dba064bfc6b1e66522d2586ae/src/anomalib/models/components/base/anomaly_module.py#L32-L54

When the validation is complete, Lightning's Trainer object calls _collect_outputs methods which computes and updates the metrics.
https://github.com/openvinotoolkit/anomalib/blob/93239858c51de63dba064bfc6b1e66522d2586ae/src/anomalib/models/components/base/anomaly_module.py#L138-L147

self._collect_outputs method does the following to compute the metrics:
https://github.com/openvinotoolkit/anomalib/blob/93239858c51de63dba064bfc6b1e66522d2586ae/src/anomalib/models/components/base/anomaly_module.py#L172-L182