def Location(child):

  """ Return x,y offset of Region

  See comment in Region.Child()

  Args:
    child: '0','1','2','3'

  Returns:
    (x,y): lower-left origin
  """

  childnum = int(child)

  x = childnum & 1 # mask the y bit
  y = childnum >> 1 # shift over the y bit

  y = not y

  return (x,y)