on_validation_epoch_end() during sanity checking will not run if val-accuracy-interval is greater than max epochs.

[reddykkeerthi]

Fixes #859

As part of the issue investigation, I tested the initial behavior by creating a dataset with annotations and passing it to the Jupyter notebook. I monkey-patched on_validation_epoch_end() to track and print how often full validation runs and at which epochs. For the test, I set val_accuracy_interval = 30 and max_epochs = 5 (i.e., val_accuracy_interval > max_epochs). As per the documentation, full validation should not run in this case. But it is actually running full validation.

Initally sanity checking happens -

Right after the sanity check, we see on_validation_epoch_end() being called and the complete validation check running -

After training on epoch 0, we see on_validation_epoch_end() being called again and the complete validation check running, since current_epoch is 0 (0 % 30 = 0) -

In the final phase, all epochs trigger on_validation_epoch_end(), but the complete validation check runs only twice—once during sanity checking and once after training when current_epoch = 0 -

All epochs have completed, and the final result is shown below:

All epochs have completed, and the final result is shown below. As expected, complete validation runs four times: during sanity checking, and when current_epoch is 0, 2, and 4

Now, I have modified the code to include a condition that checks if val_accuracy_interval is less than or equal to max_epochs. In this test, val_accuracy_interval = 30 and max_epochs = 5 (i.e., val_accuracy_interval > max_epochs). For this case, we can see that on_validation_epoch_end() is being called, but complete validation is not performed -

In addition to the Jupyter notebook testing, I’ve added test_validation_interval_greater_than_epochs in test_main.py to verify that no full validation metrics are logged when val_accuracy_interval (set to 3) is greater than max_epochs (set to 2). The test checks that box_precision, box_recall, and empty_frame_accuracy are not present in logged metrics, as full validation is skipped in this case.

Note: The case where val_accuracy_interval is less than or equal to max_epochs is already covered by test_evaluate_on_epoch_interval in the same file.

Please review and let me know if anything else is needed. Thanks!