Given the mean direction of a group of individuals, leader_direction_group
shifts the coordinate system to a new origin at the group centroid and
rotates the coordinate system by the mean direction to return each
individual's position along the mean direction, representing leadership in
terms of the front-back position in each group's mean direction. Relocation
data should be in two columns representing the X and Y coordinates, or in a
geometry column prepared by the helper function get_geometry().
Usage
leader_direction_group(
DT = NULL,
group_direction = "group_direction",
coords = NULL,
group = "group",
crs = NULL,
geometry = "geometry",
return_rank = TRUE,
ties.method = NULL
)Arguments
- DT
input data.table with group direction columns generated by
direction_groupand centroid columns generated bycentroid_group- group_direction
group_direction column name generated using
direction_group, default 'group_direction'- coords
character vector of X coordinate and Y coordinate column names. Note: the order is assumed X followed by Y column names
- group
group column name, generated by
group_pts, default 'group'- crs
numeric or character defining the coordinate reference system to be passed to sf::st_crs. For example, either
crs = "EPSG:32736"orcrs = 32736. Used only if coords are provided, see details under Interface- geometry
simple feature geometry list column name, generated by
get_geometry(). Default 'geometry', see details under Interface- return_rank
logical if rank distance should also be returned, default TRUE
- ties.method
Value
leader_direction_group returns the input DT appended with a
position_group_direction column indicating the position along the group
direction in the units of the crs and, optionally when return_rank = TRUE, a rank_position_group_direction column indicating the ranked
position along the group direction.
A message is returned when position_group_direction or
rank_position_group_direction columns already exist in the input DT,
because they will be overwritten.
See details for appending outputs using modify-by-reference in the FAQ.
Details
The function expects a data.table with relocation data appended with a
group_direction column from direction_group() and group centroid columns
from centroid_group().
The DT must be a data.table. If your data is a data.frame, you can
convert it by reference using data.table::setDT() or by reassigning using
data.table::data.table().
The group_direction argument expects the names of columns in DT which
correspond to the mean group direction generated by direction_group(). The
mean group direction column is expected in units of radians. The
return_rank argument controls if the rank of each individual's distance to
the group centroid is also returned. If return_rank is TRUE, the group
argument is required to specify the group column generated by group_pts().
The ties.method argument is passed to data.table::frank(), see details at
?data.table::frank().
See below under "Interface" for details on providing coordinates.
Interface
Two interfaces are available for providing coordinates:
Provide
coordsandcrs. Thecoordsargument expects the names of the X and Y coordinate columns. Thecrsargument expects a character string or numeric defining the coordinate reference system to be passed to sf::st_crs. For example, for UTM zone 36S (EPSG 32736), the crs argument iscrs = "EPSG:32736"orcrs = 32736. See https://spatialreference.org for a list of EPSG codes.(New!) Provide
geometry. Thegeometryargument allows the user to supply ageometrycolumn that represents the coordinates as a simple feature geometry list column. This interface expects the user to prepare their input DT withget_geometry(). To use this interface, leave thecoordsandcrsargumentsNULL, and the default argument forgeometry('geometry') will be used directly.
References
See examples of measuring leadership along group direction (also called forefront index):
See also
direction_group, centroid_group
Other Leadership functions:
direction_to_leader(),
leader_edge_delay()
Other Direction functions:
direction_group(),
direction_polarization(),
direction_step(),
direction_to_centroid(),
direction_to_leader(),
edge_alignment(),
edge_delay(),
edge_direction(),
edge_zones(),
leader_edge_delay()
Examples
# Load data.table
library(data.table)
# Read example data
DT <- fread(system.file("extdata", "DT.csv", package = "spatsoc"))
# (Subset example data to reduce example run time)
DT <- DT[year(datetime) == 2016]
# Cast the character column to POSIXct
DT[, datetime := as.POSIXct(datetime, tz = 'UTC')]
#> ID X Y datetime population
#> <char> <num> <num> <POSc> <int>
#> 1: A 715851.4 5505340 2016-11-01 00:00:54 1
#> 2: A 715822.8 5505289 2016-11-01 02:01:22 1
#> 3: A 715872.9 5505252 2016-11-01 04:01:24 1
#> 4: A 715820.5 5505231 2016-11-01 06:01:05 1
#> 5: A 715830.6 5505227 2016-11-01 08:01:11 1
#> ---
#> 7288: J 700211.6 5509087 2016-12-31 14:00:49 1
#> 7289: J 700165.3 5508825 2016-12-31 16:00:23 1
#> 7290: J 700028.7 5508826 2016-12-31 18:00:53 1
#> 7291: J 700230.9 5508609 2016-12-31 20:00:53 1
#> 7292: J 700110.1 5508383 2016-12-31 22:00:54 1
# Temporal grouping
group_times(DT, datetime = 'datetime', threshold = '20 minutes')
#> ID X Y datetime population minutes timegroup
#> <char> <num> <num> <POSc> <int> <int> <int>
#> 1: A 715851.4 5505340 2016-11-01 00:00:54 1 0 1
#> 2: A 715822.8 5505289 2016-11-01 02:01:22 1 0 2
#> 3: A 715872.9 5505252 2016-11-01 04:01:24 1 0 3
#> 4: A 715820.5 5505231 2016-11-01 06:01:05 1 0 4
#> 5: A 715830.6 5505227 2016-11-01 08:01:11 1 0 5
#> ---
#> 7288: J 700211.6 5509087 2016-12-31 14:00:49 1 0 728
#> 7289: J 700165.3 5508825 2016-12-31 16:00:23 1 0 729
#> 7290: J 700028.7 5508826 2016-12-31 18:00:53 1 0 730
#> 7291: J 700230.9 5508609 2016-12-31 20:00:53 1 0 731
#> 7292: J 700110.1 5508383 2016-12-31 22:00:54 1 0 732
# Spatial grouping with timegroup
group_pts(DT, threshold = 50, id = 'ID',
coords = c('X', 'Y'), timegroup = 'timegroup')
#> ID X Y datetime population minutes timegroup
#> <char> <num> <num> <POSc> <int> <int> <int>
#> 1: A 715851.4 5505340 2016-11-01 00:00:54 1 0 1
#> 2: A 715822.8 5505289 2016-11-01 02:01:22 1 0 2
#> 3: A 715872.9 5505252 2016-11-01 04:01:24 1 0 3
#> 4: A 715820.5 5505231 2016-11-01 06:01:05 1 0 4
#> 5: A 715830.6 5505227 2016-11-01 08:01:11 1 0 5
#> ---
#> 7288: J 700211.6 5509087 2016-12-31 14:00:49 1 0 728
#> 7289: J 700165.3 5508825 2016-12-31 16:00:23 1 0 729
#> 7290: J 700028.7 5508826 2016-12-31 18:00:53 1 0 730
#> 7291: J 700230.9 5508609 2016-12-31 20:00:53 1 0 731
#> 7292: J 700110.1 5508383 2016-12-31 22:00:54 1 0 732
#> group
#> <int>
#> 1: 1
#> 2: 2
#> 3: 3
#> 4: 4
#> 5: 5
#> ---
#> 7288: 728
#> 7289: 729
#> 7290: 5531
#> 7291: 731
#> 7292: 5532
# Calculate direction at each step
direction_step(
DT = DT,
id = 'ID',
coords = c('X', 'Y'),
crs = 32736
)
#> ID X Y datetime population minutes timegroup
#> <char> <num> <num> <POSc> <int> <int> <int>
#> 1: A 715851.4 5505340 2016-11-01 00:00:54 1 0 1
#> 2: A 715822.8 5505289 2016-11-01 02:01:22 1 0 2
#> 3: A 715872.9 5505252 2016-11-01 04:01:24 1 0 3
#> 4: A 715820.5 5505231 2016-11-01 06:01:05 1 0 4
#> 5: A 715830.6 5505227 2016-11-01 08:01:11 1 0 5
#> ---
#> 7288: J 700211.6 5509087 2016-12-31 14:00:49 1 0 728
#> 7289: J 700165.3 5508825 2016-12-31 16:00:23 1 0 729
#> 7290: J 700028.7 5508826 2016-12-31 18:00:53 1 0 730
#> 7291: J 700230.9 5508609 2016-12-31 20:00:53 1 0 731
#> 7292: J 700110.1 5508383 2016-12-31 22:00:54 1 0 732
#> group direction
#> <int> <units>
#> 1: 1 -2.65649015 [rad]
#> 2: 2 2.17592086 [rad]
#> 3: 3 -1.98432277 [rad]
#> 4: 4 1.90650150 [rad]
#> 5: 5 -0.04059949 [rad]
#> ---
#> 7288: 728 -2.99285448 [rad]
#> 7289: 729 -1.59174536 [rad]
#> 7290: 5531 2.36456688 [rad]
#> 7291: 731 -2.67757174 [rad]
#> 7292: 5532 NA [rad]
# Calculate group centroid
centroid_group(DT, coords = c('X', 'Y'))
#> ID X Y datetime population minutes timegroup
#> <char> <num> <num> <POSc> <int> <int> <int>
#> 1: A 715851.4 5505340 2016-11-01 00:00:54 1 0 1
#> 2: A 715822.8 5505289 2016-11-01 02:01:22 1 0 2
#> 3: A 715872.9 5505252 2016-11-01 04:01:24 1 0 3
#> 4: A 715820.5 5505231 2016-11-01 06:01:05 1 0 4
#> 5: A 715830.6 5505227 2016-11-01 08:01:11 1 0 5
#> ---
#> 7288: J 700211.6 5509087 2016-12-31 14:00:49 1 0 728
#> 7289: J 700165.3 5508825 2016-12-31 16:00:23 1 0 729
#> 7290: J 700028.7 5508826 2016-12-31 18:00:53 1 0 730
#> 7291: J 700230.9 5508609 2016-12-31 20:00:53 1 0 731
#> 7292: J 700110.1 5508383 2016-12-31 22:00:54 1 0 732
#> group direction centroid_X centroid_Y
#> <int> <units> <num> <num>
#> 1: 1 -2.65649015 [rad] 715851.4 5505340
#> 2: 2 2.17592086 [rad] 715822.8 5505289
#> 3: 3 -1.98432277 [rad] 715872.9 5505252
#> 4: 4 1.90650150 [rad] 715820.5 5505231
#> 5: 5 -0.04059949 [rad] 715830.6 5505227
#> ---
#> 7288: 728 -2.99285448 [rad] 700191.6 5509089
#> 7289: 729 -1.59174536 [rad] 700156.0 5508800
#> 7290: 5531 2.36456688 [rad] 700028.7 5508826
#> 7291: 731 -2.67757174 [rad] 700254.6 5508589
#> 7292: 5532 NA [rad] 700110.1 5508383
# Calculate group direction
direction_group(DT)
#> ID X Y datetime population minutes timegroup
#> <char> <num> <num> <POSc> <int> <int> <int>
#> 1: A 715851.4 5505340 2016-11-01 00:00:54 1 0 1
#> 2: A 715822.8 5505289 2016-11-01 02:01:22 1 0 2
#> 3: A 715872.9 5505252 2016-11-01 04:01:24 1 0 3
#> 4: A 715820.5 5505231 2016-11-01 06:01:05 1 0 4
#> 5: A 715830.6 5505227 2016-11-01 08:01:11 1 0 5
#> ---
#> 7288: J 700211.6 5509087 2016-12-31 14:00:49 1 0 728
#> 7289: J 700165.3 5508825 2016-12-31 16:00:23 1 0 729
#> 7290: J 700028.7 5508826 2016-12-31 18:00:53 1 0 730
#> 7291: J 700230.9 5508609 2016-12-31 20:00:53 1 0 731
#> 7292: J 700110.1 5508383 2016-12-31 22:00:54 1 0 732
#> group direction centroid_X centroid_Y group_direction
#> <int> <units> <num> <num> <units>
#> 1: 1 -2.65649015 [rad] 715851.4 5505340 -2.65649015 [rad]
#> 2: 2 2.17592086 [rad] 715822.8 5505289 2.17592086 [rad]
#> 3: 3 -1.98432277 [rad] 715872.9 5505252 -1.98432277 [rad]
#> 4: 4 1.90650150 [rad] 715820.5 5505231 1.90650150 [rad]
#> 5: 5 -0.04059949 [rad] 715830.6 5505227 -0.04059949 [rad]
#> ---
#> 7288: 728 -2.99285448 [rad] 700191.6 5509089 -3.05184005 [rad]
#> 7289: 729 -1.59174536 [rad] 700156.0 5508800 -2.41173804 [rad]
#> 7290: 5531 2.36456688 [rad] 700028.7 5508826 2.36456688 [rad]
#> 7291: 731 -2.67757174 [rad] 700254.6 5508589 -1.70798015 [rad]
#> 7292: 5532 NA [rad] 700110.1 5508383 NA [rad]
# Calculate leader in terms of position along group direction
leader_direction_group(DT, coords = c('X', 'Y'), crs = 32736)
#> ID X Y datetime population minutes timegroup
#> <char> <num> <num> <POSc> <int> <int> <int>
#> 1: A 715851.4 5505340 2016-11-01 00:00:54 1 0 1
#> 2: A 715822.8 5505289 2016-11-01 02:01:22 1 0 2
#> 3: A 715872.9 5505252 2016-11-01 04:01:24 1 0 3
#> 4: A 715820.5 5505231 2016-11-01 06:01:05 1 0 4
#> 5: A 715830.6 5505227 2016-11-01 08:01:11 1 0 5
#> ---
#> 7288: J 700211.6 5509087 2016-12-31 14:00:49 1 0 728
#> 7289: J 700165.3 5508825 2016-12-31 16:00:23 1 0 729
#> 7290: J 700028.7 5508826 2016-12-31 18:00:53 1 0 730
#> 7291: J 700230.9 5508609 2016-12-31 20:00:53 1 0 731
#> 7292: J 700110.1 5508383 2016-12-31 22:00:54 1 0 732
#> group direction centroid_X centroid_Y group_direction
#> <int> <units> <num> <num> <units>
#> 1: 1 -2.65649015 [rad] 715851.4 5505340 -2.65649015 [rad]
#> 2: 2 2.17592086 [rad] 715822.8 5505289 2.17592086 [rad]
#> 3: 3 -1.98432277 [rad] 715872.9 5505252 -1.98432277 [rad]
#> 4: 4 1.90650150 [rad] 715820.5 5505231 1.90650150 [rad]
#> 5: 5 -0.04059949 [rad] 715830.6 5505227 -0.04059949 [rad]
#> ---
#> 7288: 728 -2.99285448 [rad] 700191.6 5509089 -3.05184005 [rad]
#> 7289: 729 -1.59174536 [rad] 700156.0 5508800 -2.41173804 [rad]
#> 7290: 5531 2.36456688 [rad] 700028.7 5508826 2.36456688 [rad]
#> 7291: 731 -2.67757174 [rad] 700254.6 5508589 -1.70798015 [rad]
#> 7292: 5532 NA [rad] 700110.1 5508383 NA [rad]
#> position_group_direction rank_position_group_direction
#> <num> <num>
#> 1: 0.00000 1
#> 2: 0.00000 1
#> 3: 0.00000 1
#> 4: 0.00000 1
#> 5: 0.00000 1
#> ---
#> 7288: -19.72453 2
#> 7289: -23.62960 5
#> 7290: 0.00000 1
#> 7291: -16.87561 5
#> 7292: NA NA
# Or, using the new geometry interface
get_geometry(DT, coords = c('X', 'Y'), crs = 32736)
#> ID X Y datetime population minutes timegroup
#> <char> <num> <num> <POSc> <int> <int> <int>
#> 1: A 715851.4 5505340 2016-11-01 00:00:54 1 0 1
#> 2: A 715822.8 5505289 2016-11-01 02:01:22 1 0 2
#> 3: A 715872.9 5505252 2016-11-01 04:01:24 1 0 3
#> 4: A 715820.5 5505231 2016-11-01 06:01:05 1 0 4
#> 5: A 715830.6 5505227 2016-11-01 08:01:11 1 0 5
#> ---
#> 7288: J 700211.6 5509087 2016-12-31 14:00:49 1 0 728
#> 7289: J 700165.3 5508825 2016-12-31 16:00:23 1 0 729
#> 7290: J 700028.7 5508826 2016-12-31 18:00:53 1 0 730
#> 7291: J 700230.9 5508609 2016-12-31 20:00:53 1 0 731
#> 7292: J 700110.1 5508383 2016-12-31 22:00:54 1 0 732
#> group direction centroid_X centroid_Y group_direction
#> <int> <units> <num> <num> <units>
#> 1: 1 -2.65649015 [rad] 715851.4 5505340 -2.65649015 [rad]
#> 2: 2 2.17592086 [rad] 715822.8 5505289 2.17592086 [rad]
#> 3: 3 -1.98432277 [rad] 715872.9 5505252 -1.98432277 [rad]
#> 4: 4 1.90650150 [rad] 715820.5 5505231 1.90650150 [rad]
#> 5: 5 -0.04059949 [rad] 715830.6 5505227 -0.04059949 [rad]
#> ---
#> 7288: 728 -2.99285448 [rad] 700191.6 5509089 -3.05184005 [rad]
#> 7289: 729 -1.59174536 [rad] 700156.0 5508800 -2.41173804 [rad]
#> 7290: 5531 2.36456688 [rad] 700028.7 5508826 2.36456688 [rad]
#> 7291: 731 -2.67757174 [rad] 700254.6 5508589 -1.70798015 [rad]
#> 7292: 5532 NA [rad] 700110.1 5508383 NA [rad]
#> position_group_direction rank_position_group_direction
#> <num> <num>
#> 1: 0.00000 1
#> 2: 0.00000 1
#> 3: 0.00000 1
#> 4: 0.00000 1
#> 5: 0.00000 1
#> ---
#> 7288: -19.72453 2
#> 7289: -23.62960 5
#> 7290: 0.00000 1
#> 7291: -16.87561 5
#> 7292: NA NA
#> geometry
#> <sfc_POINT>
#> 1: POINT (715851.4 5505340)
#> 2: POINT (715822.8 5505289)
#> 3: POINT (715872.9 5505252)
#> 4: POINT (715820.5 5505231)
#> 5: POINT (715830.6 5505227)
#> ---
#> 7288: POINT (700211.6 5509087)
#> 7289: POINT (700165.3 5508825)
#> 7290: POINT (700028.7 5508826)
#> 7291: POINT (700230.9 5508609)
#> 7292: POINT (700110.1 5508383)
direction_step(DT = DT, id = 'ID')
#> direction column will be overwritten by this function
#> ID X Y datetime population minutes timegroup
#> <char> <num> <num> <POSc> <int> <int> <int>
#> 1: A 715851.4 5505340 2016-11-01 00:00:54 1 0 1
#> 2: A 715822.8 5505289 2016-11-01 02:01:22 1 0 2
#> 3: A 715872.9 5505252 2016-11-01 04:01:24 1 0 3
#> 4: A 715820.5 5505231 2016-11-01 06:01:05 1 0 4
#> 5: A 715830.6 5505227 2016-11-01 08:01:11 1 0 5
#> ---
#> 7288: J 700211.6 5509087 2016-12-31 14:00:49 1 0 728
#> 7289: J 700165.3 5508825 2016-12-31 16:00:23 1 0 729
#> 7290: J 700028.7 5508826 2016-12-31 18:00:53 1 0 730
#> 7291: J 700230.9 5508609 2016-12-31 20:00:53 1 0 731
#> 7292: J 700110.1 5508383 2016-12-31 22:00:54 1 0 732
#> group centroid_X centroid_Y group_direction position_group_direction
#> <int> <num> <num> <units> <num>
#> 1: 1 715851.4 5505340 -2.65649015 [rad] 0.00000
#> 2: 2 715822.8 5505289 2.17592086 [rad] 0.00000
#> 3: 3 715872.9 5505252 -1.98432277 [rad] 0.00000
#> 4: 4 715820.5 5505231 1.90650150 [rad] 0.00000
#> 5: 5 715830.6 5505227 -0.04059949 [rad] 0.00000
#> ---
#> 7288: 728 700191.6 5509089 -3.05184005 [rad] -19.72453
#> 7289: 729 700156.0 5508800 -2.41173804 [rad] -23.62960
#> 7290: 5531 700028.7 5508826 2.36456688 [rad] 0.00000
#> 7291: 731 700254.6 5508589 -1.70798015 [rad] -16.87561
#> 7292: 5532 700110.1 5508383 NA [rad] NA
#> rank_position_group_direction geometry direction
#> <num> <sfc_POINT> <units>
#> 1: 1 POINT (715851.4 5505340) -2.65649015 [rad]
#> 2: 1 POINT (715822.8 5505289) 2.17592086 [rad]
#> 3: 1 POINT (715872.9 5505252) -1.98432277 [rad]
#> 4: 1 POINT (715820.5 5505231) 1.90650150 [rad]
#> 5: 1 POINT (715830.6 5505227) -0.04059949 [rad]
#> ---
#> 7288: 2 POINT (700211.6 5509087) -2.99285448 [rad]
#> 7289: 5 POINT (700165.3 5508825) -1.59174536 [rad]
#> 7290: 1 POINT (700028.7 5508826) 2.36456688 [rad]
#> 7291: 5 POINT (700230.9 5508609) -2.67757174 [rad]
#> 7292: NA POINT (700110.1 5508383) NA [rad]
centroid_group(DT)
#> ID X Y datetime population minutes timegroup
#> <char> <num> <num> <POSc> <int> <int> <int>
#> 1: A 715851.4 5505340 2016-11-01 00:00:54 1 0 1
#> 2: A 715822.8 5505289 2016-11-01 02:01:22 1 0 2
#> 3: A 715872.9 5505252 2016-11-01 04:01:24 1 0 3
#> 4: A 715820.5 5505231 2016-11-01 06:01:05 1 0 4
#> 5: A 715830.6 5505227 2016-11-01 08:01:11 1 0 5
#> ---
#> 7288: J 700211.6 5509087 2016-12-31 14:00:49 1 0 728
#> 7289: J 700165.3 5508825 2016-12-31 16:00:23 1 0 729
#> 7290: J 700028.7 5508826 2016-12-31 18:00:53 1 0 730
#> 7291: J 700230.9 5508609 2016-12-31 20:00:53 1 0 731
#> 7292: J 700110.1 5508383 2016-12-31 22:00:54 1 0 732
#> group centroid_X centroid_Y group_direction position_group_direction
#> <int> <num> <num> <units> <num>
#> 1: 1 715851.4 5505340 -2.65649015 [rad] 0.00000
#> 2: 2 715822.8 5505289 2.17592086 [rad] 0.00000
#> 3: 3 715872.9 5505252 -1.98432277 [rad] 0.00000
#> 4: 4 715820.5 5505231 1.90650150 [rad] 0.00000
#> 5: 5 715830.6 5505227 -0.04059949 [rad] 0.00000
#> ---
#> 7288: 728 700191.6 5509089 -3.05184005 [rad] -19.72453
#> 7289: 729 700156.0 5508800 -2.41173804 [rad] -23.62960
#> 7290: 5531 700028.7 5508826 2.36456688 [rad] 0.00000
#> 7291: 731 700254.6 5508589 -1.70798015 [rad] -16.87561
#> 7292: 5532 700110.1 5508383 NA [rad] NA
#> rank_position_group_direction geometry direction
#> <num> <sfc_POINT> <units>
#> 1: 1 POINT (715851.4 5505340) -2.65649015 [rad]
#> 2: 1 POINT (715822.8 5505289) 2.17592086 [rad]
#> 3: 1 POINT (715872.9 5505252) -1.98432277 [rad]
#> 4: 1 POINT (715820.5 5505231) 1.90650150 [rad]
#> 5: 1 POINT (715830.6 5505227) -0.04059949 [rad]
#> ---
#> 7288: 2 POINT (700211.6 5509087) -2.99285448 [rad]
#> 7289: 5 POINT (700165.3 5508825) -1.59174536 [rad]
#> 7290: 1 POINT (700028.7 5508826) 2.36456688 [rad]
#> 7291: 5 POINT (700230.9 5508609) -2.67757174 [rad]
#> 7292: NA POINT (700110.1 5508383) NA [rad]
#> centroid
#> <sfc_POINT>
#> 1: POINT (715851.4 5505340)
#> 2: POINT (715822.8 5505289)
#> 3: POINT (715872.9 5505252)
#> 4: POINT (715820.5 5505231)
#> 5: POINT (715830.6 5505227)
#> ---
#> 7288: POINT (700191.6 5509089)
#> 7289: POINT (700156 5508800)
#> 7290: POINT (700028.7 5508826)
#> 7291: POINT (700254.6 5508589)
#> 7292: POINT (700110.1 5508383)
direction_group(DT)
#> group_direction column will be overwritten by this function
#> ID X Y datetime population minutes timegroup
#> <char> <num> <num> <POSc> <int> <int> <int>
#> 1: A 715851.4 5505340 2016-11-01 00:00:54 1 0 1
#> 2: A 715822.8 5505289 2016-11-01 02:01:22 1 0 2
#> 3: A 715872.9 5505252 2016-11-01 04:01:24 1 0 3
#> 4: A 715820.5 5505231 2016-11-01 06:01:05 1 0 4
#> 5: A 715830.6 5505227 2016-11-01 08:01:11 1 0 5
#> ---
#> 7288: J 700211.6 5509087 2016-12-31 14:00:49 1 0 728
#> 7289: J 700165.3 5508825 2016-12-31 16:00:23 1 0 729
#> 7290: J 700028.7 5508826 2016-12-31 18:00:53 1 0 730
#> 7291: J 700230.9 5508609 2016-12-31 20:00:53 1 0 731
#> 7292: J 700110.1 5508383 2016-12-31 22:00:54 1 0 732
#> group centroid_X centroid_Y position_group_direction
#> <int> <num> <num> <num>
#> 1: 1 715851.4 5505340 0.00000
#> 2: 2 715822.8 5505289 0.00000
#> 3: 3 715872.9 5505252 0.00000
#> 4: 4 715820.5 5505231 0.00000
#> 5: 5 715830.6 5505227 0.00000
#> ---
#> 7288: 728 700191.6 5509089 -19.72453
#> 7289: 729 700156.0 5508800 -23.62960
#> 7290: 5531 700028.7 5508826 0.00000
#> 7291: 731 700254.6 5508589 -16.87561
#> 7292: 5532 700110.1 5508383 NA
#> rank_position_group_direction geometry direction
#> <num> <sfc_POINT> <units>
#> 1: 1 POINT (715851.4 5505340) -2.65649015 [rad]
#> 2: 1 POINT (715822.8 5505289) 2.17592086 [rad]
#> 3: 1 POINT (715872.9 5505252) -1.98432277 [rad]
#> 4: 1 POINT (715820.5 5505231) 1.90650150 [rad]
#> 5: 1 POINT (715830.6 5505227) -0.04059949 [rad]
#> ---
#> 7288: 2 POINT (700211.6 5509087) -2.99285448 [rad]
#> 7289: 5 POINT (700165.3 5508825) -1.59174536 [rad]
#> 7290: 1 POINT (700028.7 5508826) 2.36456688 [rad]
#> 7291: 5 POINT (700230.9 5508609) -2.67757174 [rad]
#> 7292: NA POINT (700110.1 5508383) NA [rad]
#> centroid group_direction
#> <sfc_POINT> <units>
#> 1: POINT (715851.4 5505340) -2.65649015 [rad]
#> 2: POINT (715822.8 5505289) 2.17592086 [rad]
#> 3: POINT (715872.9 5505252) -1.98432277 [rad]
#> 4: POINT (715820.5 5505231) 1.90650150 [rad]
#> 5: POINT (715830.6 5505227) -0.04059949 [rad]
#> ---
#> 7288: POINT (700191.6 5509089) -3.05184005 [rad]
#> 7289: POINT (700156 5508800) -2.41173804 [rad]
#> 7290: POINT (700028.7 5508826) 2.36456688 [rad]
#> 7291: POINT (700254.6 5508589) -1.70798015 [rad]
#> 7292: POINT (700110.1 5508383) NA [rad]
leader_direction_group(DT)
#> position_group_direction column will be overwritten by this function
#> rank_position_group_direction column will be overwritten by this function
#> ID X Y datetime population minutes timegroup
#> <char> <num> <num> <POSc> <int> <int> <int>
#> 1: A 715851.4 5505340 2016-11-01 00:00:54 1 0 1
#> 2: A 715822.8 5505289 2016-11-01 02:01:22 1 0 2
#> 3: A 715872.9 5505252 2016-11-01 04:01:24 1 0 3
#> 4: A 715820.5 5505231 2016-11-01 06:01:05 1 0 4
#> 5: A 715830.6 5505227 2016-11-01 08:01:11 1 0 5
#> ---
#> 7288: J 700211.6 5509087 2016-12-31 14:00:49 1 0 728
#> 7289: J 700165.3 5508825 2016-12-31 16:00:23 1 0 729
#> 7290: J 700028.7 5508826 2016-12-31 18:00:53 1 0 730
#> 7291: J 700230.9 5508609 2016-12-31 20:00:53 1 0 731
#> 7292: J 700110.1 5508383 2016-12-31 22:00:54 1 0 732
#> group centroid_X centroid_Y geometry direction
#> <int> <num> <num> <sfc_POINT> <units>
#> 1: 1 715851.4 5505340 POINT (715851.4 5505340) -2.65649015 [rad]
#> 2: 2 715822.8 5505289 POINT (715822.8 5505289) 2.17592086 [rad]
#> 3: 3 715872.9 5505252 POINT (715872.9 5505252) -1.98432277 [rad]
#> 4: 4 715820.5 5505231 POINT (715820.5 5505231) 1.90650150 [rad]
#> 5: 5 715830.6 5505227 POINT (715830.6 5505227) -0.04059949 [rad]
#> ---
#> 7288: 728 700191.6 5509089 POINT (700211.6 5509087) -2.99285448 [rad]
#> 7289: 729 700156.0 5508800 POINT (700165.3 5508825) -1.59174536 [rad]
#> 7290: 5531 700028.7 5508826 POINT (700028.7 5508826) 2.36456688 [rad]
#> 7291: 731 700254.6 5508589 POINT (700230.9 5508609) -2.67757174 [rad]
#> 7292: 5532 700110.1 5508383 POINT (700110.1 5508383) NA [rad]
#> centroid group_direction position_group_direction
#> <sfc_POINT> <units> <num>
#> 1: POINT (715851.4 5505340) -2.65649015 [rad] 0.00000
#> 2: POINT (715822.8 5505289) 2.17592086 [rad] 0.00000
#> 3: POINT (715872.9 5505252) -1.98432277 [rad] 0.00000
#> 4: POINT (715820.5 5505231) 1.90650150 [rad] 0.00000
#> 5: POINT (715830.6 5505227) -0.04059949 [rad] 0.00000
#> ---
#> 7288: POINT (700191.6 5509089) -3.05184005 [rad] -19.72453
#> 7289: POINT (700156 5508800) -2.41173804 [rad] -23.62960
#> 7290: POINT (700028.7 5508826) 2.36456688 [rad] 0.00000
#> 7291: POINT (700254.6 5508589) -1.70798015 [rad] -16.87561
#> 7292: POINT (700110.1 5508383) NA [rad] NA
#> rank_position_group_direction
#> <num>
#> 1: 1
#> 2: 1
#> 3: 1
#> 4: 1
#> 5: 1
#> ---
#> 7288: 2
#> 7289: 5
#> 7290: 1
#> 7291: 5
#> 7292: NA