code: def _loc_vec(self, loc):
          
          gxy = self.scale_xy*(loc[:, :2, :] - self.dboxes[:, :2, :])/self.dboxes[:, 2:, ]
          gwh = self.scale_wh*(loc[:, 2:, :]/self.dboxes[:, 2:, :]).log()
  
          return torch.cat((gxy, gwh), dim=1).contiguous()
docs: Generate Location Vectors