def removeBelowValue(requestContext, seriesList, n):
  """
  Removes data below the given threshold from the series or list of series provided.
  Values below this threshold are assigned a value of None.
  """
  for s in seriesList:
    s.name = 'removeBelowValue(%s, %d)' % (s.name, n)
    s.pathExpression = s.name
    for (index, val) in enumerate(s):
      if val < n:
        s[index] = None

  return seriesList