Available features:
1. kinematic features
1. velocity
2. acceleration
3. jerk
2. dynamic features
1. azimuth
2. tilt
3. pressure
3. spatial features
1. stroke length
2. stroke height
3. stroke width
4. writing length
5. writing height
6. writing width
7. number of intra-stroke intersections
8. relative number of intra-stroke intersections
9. total number of intra-stroke intersections
10. relative total number of intra-stroke intersections
11. number of inter-stroke intersections
12. relative number of inter-stroke intersections
13. vertical peaks indices
14. vertical valleys indices
15. vertical peaks values
16. vertical valleys values
17. vertical peaks velocity
18. vertical valleys velocity
19. vertical peaks distance
20. vertical valleys distance
21. vertical peaks duration
22. vertical valleys duration
4. temporal features
1. stroke duration
2. ratio of stroke durations (on-surface / in-air strokes)
3. writing duration
4. writing duration overall
5. ratio of writing durations (on-surface / in-air writing)
6. number of interruptions
7. number of interruptions relative
5. composite features
1. writing tempo
2. writing stops
3. number of changes in x profile
4. number of changes in y profile
5. number of changes in azimuth
6. number of changes in tilt
7. number of changes in pressure
8. number of changes in velocity profile
9. relative number of changes in x profile
10. relative number of changes in y profile
11. relative number of changes in azimuth
12. relative number of changes in tilt
13. relative number of changes in pressure
14. relative number of changes in velocity profile