mid-stroke area covered
20%-perc. pairwise velocity
mid-stroke pressure
direction of end-to-end line
stop x
start x
average direction
start y
average velocity
stop y
stroke duration
direct end-to-end distance
length of trajectory
80%-perc. pairwise velocity
median velocity at last 3 pts
50%-perc. pairwise velocity
20%-perc. pairwise acc
ratio end-to-end dist and length of trajectory
largest deviation from end-to-end line
80%-perc. pairwise acc
mean resultant lenght
median acceleration at first 5 points
50%-perc. dev. from end-to-end line
inter-stroke time
80%-perc. dev. from end-to-end line
20%-perc. dev. from end-to-end line
50%-perc. pairwise acc
phone orientation
mid-stroke finger orientation
up/down/left/right flag
change of finger orientation