Table 6.

Criteria for feature selection.

	Feature set	NLSVM- $\mathbf{CO}$ (%)	NLSVM- $\mathbf{HC}$ (%)	LSVM- $\mathbf{N}{\mathbf{O}}_{\mathbf{x}}$ (%)	NLSVM- $\mathbf{C}{\mathbf{O}}_2$ (%)
$J_{\mathrm{CFS}}(R^2)$	FS = L13	4.53	0.41	7.56	−1.75
	FS = S14	5.12	2.60	−2.57	−1.38
	FS = S20	4.78	0.59	5.09	0.34
	FS = S26	4.66	0.28	4.02	−0.17
	Selected FS	L13	L7	L13	L7