Table 3.

Feature selection for stage and grade analysis

Width of	Concavity	Contour	Surface	Surface	Information
affected	change rate	gap (c)	edge no.	edge length	gain
area (w)	(ΔCI)		(en)	(el)	(IG)
√	√	×	×	×	0.7589
√	×	√	×	×	0.9163
√	×	×	√	×	0.2706
√	×	×	×	√	0.1663