code: def scale_flow(flow, to_unit=True):
      "Scale the coords in `flow` to -1/1 or the image size depending on `to_unit`."
      s = tensor([flow.size[0]/2,flow.size[1]/2])[None]
      if to_unit: flow.flow = flow.flow/s-1
      else:       flow.flow = (flow.flow+1)*s
      return flof scale_flow(flow, to_unit=True):
      "Scale the coords in `flow` to -1/1 or the image size depending on `to_unit`."
      s = tensor([flow.size[0]/2,flow.size[1]/2])[None]
      if to_unit: flow.flow = flow.flow/s-1
      else:       flow.flow = (flow.flow+1)*s
      return flow
docs: Scale the coords in `flow` to -1/1 or the image size depending on `to_unit`.