ignore_index option in metrics

[mrugnivenko]

I think that the ignore_index option in the metrics calculation isn't working right.

Suppose I have 4 indexes - 0,1,2,3 and I wan't to ignore index 0 at metric calculation, then true positive output of smp.metrics.get_stats function with ignore_index=0 gives me [0, tp_for_index_1, tp_for_index_2, tp_for_index_3], so than futher calculation of dice score with "macro" averaging will account for that zero:

dice = (0 + dice_for_index_1 + dice_for_index_2 + dice_for_index_3)/4 - that isn't right assesment of dice, since I want to ignore the contribution of index=0

The right way to calculate "macro" dice will be

dice = (dice_for_index_1 + dice_for_index_2 + dice_for_index_3)/3

[qubvel]

Hi, thanks for the comment, you are right.
I will think how to fix it. If you have any suggestions, you are welcome 😊

[qubvel]

Not the best fix, however, it will prevent unpredicted behavior