Gathers values along an axis specified by dim with indices. torch.gather — PyTorch 2.3 documentationinput and index must have the same number of dimensions. It is also required that index.size(d) <= input.size(d) for all dimensions d != dim. out will have the same shape as index. Note that input and index do not broadcast against each other.https://pytorch.org/docs/stable/generated/torch.gather.html