From: 3D facial expression recognition using maximum relevance minimum redundancy geometrical features
s 1 =( β 2 ′ − β 1 ′ )
s 2 =( β 2 ′ − β 3 ′ )
s 3 =( β 5 ′ − β 4 ′ )
s 4 =( β 5 ′ − β 6 ′ )
s 7 =( β 9 ′ − β 8 ′ )
s 8 =( β 9 ′ − β 13 ′ )
s 9 =( β 7 ′ − β 1 ′ )
s 7 =( β 2 ′ − β 8 ′ )
s 11 =( β 7 ′ − β 13 ′ )
s 12 =( β 9 ′ − β 3 ′ )
s 13 =( β 9 ′ − β 8 ′ )
s 14 =( β 9 ′ − β 13 ′ )
s 15 =( β 10 ′ − β 4 ′ )
s 16 =( β 10 ′ − β 11 ′ )
s 17 =( β 10 ′ − β 14 ′ )
s 18 =( β 12 ′ − β 6 ′ )
s 19 =( β 12 ′ − β 11 ′ )
s 20 =( β 12 ′ − β 14 ′ )
s 21 =( β 21 ′ − β 7 ′ )
s 22 =( β 21 ′ − β 16 ′ )
s 23 =( β 21 ′ − β 22 ′ )
s 24 =( β 21 ′ − β 28 ′ )
s 25 =( β 21 ′ − β 29 ′ )
s 26 =( β 22 ′ − β 17 ′ )
s 27 =( β 23 ′ − β 24 ′ )
s 28 =( β 23 ′ − β 22 ′ )
s 29 =( β 24 ′ − β 19 ′ )
s 30 =( β 25 ′ − β 12 ′ )
s 31 =( β 25 ′ − β 20 ′ )
s 32 =( β 25 ′ − β 24 ′ )
s 33 =( β 25 ′ − β 26 ′ )
s 34 =( β 25 ′ − β 31 ′ )
s 35 =( β 27 ′ − β 26 ′ )
s 36 =( β 27 ′ − β 8 ′ )
s 37 =( β 30 ′ − β 31 ′ )
s 38 =( β 30 ′ − β 29 ′ )