What is the gather index?

**This is more of a question than issue.**

In model.py at line number 330 gather index has been used to re-orient text and image embedding after concatenation. I am trying to understand what is this gather index conceptually. I am trying to find the same in the paper. From the paper it seems image and text features are concatenated. So it will be helpful to know what these gather index vectors represents and how to create them for a custom dataset.

Thanks.

Read model.py around line 330 and compare the concatenation and re-orientation logic with the paper. Trace how the gather index vectors are formed in the existing data path. Done means documenting what they represent and how they should be created for a custom dataset.

Written by the indexing model from the issue text.