Analysis of the Abnormality of Traction Energy Consumption in Urban Rail Transit System

Algorithm 1

Discretization of the PAA representation of time series into SAX.

	Require: T:24-dimensional original TEC time series data, n:the length of time series discord.
	Ensure: The length of Discord and strings of length .
(1)	function Z-normalization
(2)
(3)
(4)
(5)	Z-NORMALIZATION
(6)	function PAA
(7)
(8)	ifthen
(9)
(10)	else ifthen
(11)	colMeans (matrix (ts, nrow = len %/% paa_size, byrow = F))
(12)	else
(13)	res = rep.int (0, paa_size)
(14)	end if
(15)	return
(16)	end function
(17)	Use the 4 symbols alphabet a,b,c,d
(18)	SAX transform of ts into string through 9-points PAA: “baabccbc”:
(19)	ts_to_string (dat_paa_9, cuts_for_asize (9))
(20)