code: def error_value_processor(value, error):
      
      if isinstance(error, (str, unicode)):
          try:
              if "%" in error:
                  error_float = float(error.replace("%", ""))
                  error_abs = (value/100) * error_float
                  return error_abs
              elif error == "":
                  error = 0.0
              else:
                  error = float(error)
          except:
              pass
  
      return error
docs: If an error is a percentage, we convert to a float, then
      calculate the percentage of the supplied value.
  
      :param value: base value, e.g. 10
      :param error: e.g. 20.0%
      :return: the absolute error, e.g. 12 for the above case.