code: import torch
  
  
  def rel_positions_grid(grid_sizes):
      """Generates a flattened grid of (x,y,...) coordinates in a range of -1 to 1.
      sidelen: int
      dim: int
      """
      tensors = []
      for size in grid_sizes:
          tensors.append(torch.linspace(-1, 1, steps=size))
      # tensors = tuple(dim * [torch.linspace(-1, 1, steps=grid_length)])
      relpos_grid = torch.stack(torch.meshgrid(*tensors), dim=-0)
      return relpos_grid
  
apis: torch.linspace torch.meshgrid