Table 7.

Relationship between gray correlation coefficient and gray correlation degree.

	ζPHE	ζCd	$\gamma$(GRG)
1	0.33	0.33	0.33
2	0.38	0.37	0.37
3	0.40	0.39	0.40
4	0.50	0.61	0.55
5	0.73	0.72	0.73
6	1	0.67	0.83
7	0.67	0.71	0.69
8	0.79	0.81	0.80
9	0.84	1	0.92