Potential bug in masked_accuracy.

[DuskNgai]

In src/membrain_seg/segmentation/training/metric_utils.py, I found when ignore_label is set to None, the function returns a nan. I examined the code and found that there may be a bug in your function masked_accuracy:

def masked_accuracy(...):
    ...
    mask = (
        y_gt == ignore_label
        if ignore_label is not None
        else torch.ones_like(y_gt).bool()
    )

I think it should be torch.zeros_like(y_gt).bool() instead of torch.ones_like(y_gt).bool().

Looking forward to your reply and hope it can be fixed soon~

[LorenzLamm]

Thanks a lot for pointing out! I never used it without setting the ignore label, so this didn't appear to me.
But you're absolutely correct. I fixed the bug in the latest PR (#45).

[LorenzLamm]

Merged now into the main repository, so closing this issue