Features from a Single Vector Pressure Stroke

Table 6

Performance features.

Number	Feature	Definition	Formula and value
1		Area of
2		Area of convex
3		Times of turning left
4		Times of turning right
5		Self-intersection times
6		Number of knee points
7		Number of -axis knee points
8		Number of -axis knee points
9		Number of inflection points
10		Slope of segment
11		Aspect ratio of
12		Ratio of turning left
13		Ratio of turning right
14		Max. ratio of deviation
		Min. ratio of deviation
15		Speed of point
16		Average speed of point
17		Size of speed
18		Max. ratio of deviation
19		Min. ratio of deviation
20		Acceleration of point