about rpn_loss_box is zero

[ww451575464]

i found rpn_loss_box has always been zero, and that because bbox_outside_weights is 0.
maybe i should change
positive_weights = 1.0 / num_examples
negative_weights = 1.0 / num_examples
to
positive_weights = 1.0 / num_examples.item()
negative_weights = 1.0 / num_examples.item()
in anchor_target_layer_fpn.py line 136