Kernel Local Linear Discriminate Method for Dimensionality Reduction and Its Application in Machinery Fault Diagnosis

Table 4

Comparison of within-class distance of low dimension using four dimensionality reduction methods.

	Normal	Inner race fault	Ball fault	Outer race fault
KPCA	1.62×10^3	1.51×10^6	5.74×10^6	6.76×10^7
	2.67×10^7	1.63×10^7	4.97×10^6	1.33×10^8
NPP	5.14×10^−4	5.03×10^−4	1.42×10^−3	1.68×10^−3
	7.01×10^−4	2.64×10^−4	2.08×10^−4	1.53×10^−4
LLD	1.84×10^−3	5.98×10^−4	1.81×10^−3	3.28×10^−3
	2.91×10^−3	1.61×10^−3	9.31×10^−4	7.58×10^−4
KLLD	1.28×10^−13	7.80×10^−12	5.38×10^−12	2.09×10^−12
	2.46×10^−3	1.28×10^−3	7.06×10^−4	5.87×10^−4