code: def local_error(self, originalValue, calculatedValue):
          
          originalValue = originalValue[0]
          calculatedValue = calculatedValue[0]
  
          return abs(originalValue - calculatedValue)
docs: Calculates the error between the two given values.
  
          :param list originalValue:    List containing the values of the original data.
          :param list calculatedValue:    List containing the values of the calculated TimeSeries that
              corresponds to originalValue.
  
          :return:    Returns the error measure of the two given values.
          :rtype:     numeric