Skip to main content

Advertisement

Table 1 The initial 32 features derived from the spatio-temporal footprint of each user

From: Travelers or locals? Identifying meaningful sub-populations from human movement data in the absence of ground truth

  Feature name Clarification and description Feature type
1 Active days The number of days the user has used the app Temporal Activity
2 Consecutive days The highest number of consecutive days the user has used the app Temporal Activity
3 Weekdays The number of distinct weekdays the user has used the app Temporal Activity
4 Period The number of days between the first and last usage Temporal Activity
5 Total time The total amount of time the app has been running [s] Temporal Activity
6 Variation of time stamp The standard deviation of all time stamps [s] Temporal Activity
7 Total distance The total distance the user has covered [m] Spatial Distance
8 Maximum distance The distance between two most distant points a user has visited [m] Spatial Distance
9 Daily distance The average distance covered in a day [m] Spatial Distance
10 Variation of daily distance The standard deviation of the average distances per day [m] Spatial Distance
11 Daily centroid distance The average distance of two consecutiveFootnote

Consecutive refers to the next day the app has been used, which does not necessarily mean the immediately following day.

daily centroids [m] The centroid is the centroid of the daily concave hull
Spatial Distance
12 Variation of daily centroid distance The standard deviation of the distance between two consecutive daily centroids [m] Spatial Distance
13 Distance to centroid The average distance between the daily centroid and the overall centroid [m] Spatial Distance
14 Variation of distance to centroid The standard deviation of the distance between the daily centroid and the overall centroid [m] Spatial Distance
15 Average step length The average distance covered in a move segmentFootnote

A move segment describes a segment of continuous movement without a stop segment. A stop segment is a series of GPS tuples with almost no movement (sum of covered distances shorter than 10 m) in a five-minute window (see also Sect. 4).

[m]
Spatial Distance
16 Standard deviation of step length The standard deviation of the distances covered in move segments [m] Spatial Distance
17 Area The total area the user has covered [m2]Footnote

We used a concave hull to compute the areal measures.

Spatial Area
18 Circumference The circumference of the total area the user has covered [m] Spatial Area
19 Complexity The complexity of the total area (area/circumference) Spatial Area
20 Compactness The compactness of the total area [4area/πmaximum distance squared] Spatial Area
21 Daily area The average area of the daily areas covered [m2] Spatial Area
22 Variation of daily area The standard deviation of the daily areas covered [m2] Spatial Variability
23 Overlap The average percent of overlap of two consecutive daily areas covered [%] Spatial Variability
24 Variation of overlap The standard deviation of the percentage of overlap of two consecutive daily areas covered [%] Spatial Variability
25 Spatial clusters The number of clusters of start, stop or end pointsFootnote

See also the definition of significant locations in Sect. 5.

Spatial Variability
26 Number of moves The absolute number of move segments Spatio-Temporal Dynamics
27 Average speed The average speed in the move segments [m/s] Spatio-Temporal Dynamics
28 Standard deviation of speed The standard deviation of the speed in the move segments [m/s] Spatio-Temporal Dynamics
29 Number of stops The total number of stops Spatio-Temporal Dynamics
30 Total stop duration The total duration of all stops [s] Spatio-Temporal Dynamics
31 Stop duration The average duration of a stop [s] Spatio-Temporal Dynamics
32 Variation of stop duration The standard deviation of the stops [s] Spatio-Temporal Dynamics