Questions about calculate_weights()

Hi Andrey, I have a couple of questions about calculate_weights().
1. in line 106-109, why do you need expand_as(self.y)?
2. in line 118, why do you need to divide g by (2 * math.pi * sigma ** 2)? I cannot find this in the original expression of Gabor filters.
Thank you!

Locate calculate_weights() and read lines 106-118, focusing on the expand_as(self.y) call and the normalization of g. Compare those operations with the original Gabor-filter expression referenced by the issue. Done means documenting clear explanations for both questions in the relevant project documentation or code comments.

Written by the indexing model from the issue text.