Change Point Detection for Piecewise Envelope Current Signal Based on Wavelet Transform

Table 5

Comparison of relative error of the envelope method and the direct method.

	Relative error/%	db2	Sym2	Coif1	bior2.2
change point 1	envelope method	0.6771	0.6771	5.9896	5.9896
	direct method	0.1042	0.1042	0.0521	0.0521
change point 2	envelope method	0.4062	0.4062	3.5937	3.5937
	direct method	0.0625	0.0625	0.0312	0.0312
change point 3	envelope method	2.2461	2.2461	0.2539	0.2539
	direct method	0.0391	0.0391	0.0586	0.0586