library(spatsoc)
library(data.table)

DT <- fread(system.file("extdata", "DT.csv", package = "spatsoc"))
id <- 'ID'
datetime <- 'datetime'
timethreshold <- '20 minutes'
threshold <- 50
coords <- c('X', 'Y')
timegroup <- 'timegroup'
utm <- 32736

DT[, datetime := as.POSIXct(datetime, tz = 'UTC')]

get_geometry(DT, coords = coords, crs = utm)
group_times(DT, datetime = datetime, threshold = timethreshold)
#>            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
#>    ---                                                       
#> 14293:      J 700616.5 5509069 2017-02-28 14:00:54          1
#> 14294:      J 700622.6 5509065 2017-02-28 16:00:11          1
#> 14295:      J 700657.5 5509277 2017-02-28 18:00:55          1
#> 14296:      J 700610.3 5509269 2017-02-28 20:00:48          1
#> 14297:      J 700744.0 5508782 2017-02-28 22:00:39          1
#>                        geometry minutes timegroup
#>                     <sfc_POINT>   <int>     <int>
#>     1: POINT (715851.4 5505340)       0         1
#>     2: POINT (715822.8 5505289)       0         2
#>     3: POINT (715872.9 5505252)       0         3
#>     4: POINT (715820.5 5505231)       0         4
#>     5: POINT (715830.6 5505227)       0         5
#>    ---                                           
#> 14293: POINT (700616.5 5509069)       0      1393
#> 14294: POINT (700622.6 5509065)       0      1394
#> 14295: POINT (700657.5 5509277)       0      1440
#> 14296: POINT (700610.3 5509269)       0      1395
#> 14297:   POINT (700744 5508782)       0      1396
edges <- edge_dist(DT, threshold = threshold, id = id, coords = coords,
                   timegroup = timegroup, returnDist = TRUE, fillNA = FALSE)
dyad_id(edges, id1 = 'ID1', id2 = 'ID2')
#>        timegroup    ID1    ID2  distance dyadID
#>            <int> <char> <char>     <num> <char>
#>     1:         1      G      B  5.782904    B-G
#>     2:         1      B      G  5.782904    B-G
#>     3:         4      G      B 21.129001    B-G
#>     4:         4      H      E 11.961466    E-H
#>     5:         4      B      G 21.129001    B-G
#>    ---                                         
#> 12652:      1440      I      C  2.831071    C-I
#> 12653:      1440      C      F  9.372972    C-F
#> 12654:      1440      I      F  7.512922    F-I
#> 12655:      1440      C      I  2.831071    C-I
#> 12656:      1440      F      I  7.512922    F-I
fusion_id(edges, threshold = threshold)

cent <- centroid_fusion(edges = edges, DT = DT, id = id)

edge_direction(edges = cent, DT = DT, id = id)
#> Linking to GEOS 3.14.1, GDAL 3.12.0, PROJ 9.7.0; sf_use_s2() is TRUE
#>        timegroup    ID1    ID2 dyadID  distance fusionID
#>            <int> <char> <char> <char>     <num>    <int>
#>     1:         1      G      B    B-G  5.782904        1
#>     2:         1      B      G    B-G  5.782904        1
#>     3:         4      G      B    B-G 21.129001        2
#>     4:         4      H      E    E-H 11.961466        3
#>     5:         4      B      G    B-G 21.129001        2
#>    ---                                                  
#> 12652:      1440      I      C    C-I  2.831071     3349
#> 12653:      1440      C      F    C-F  9.372972     3348
#> 12654:      1440      I      F    F-I  7.512922     3350
#> 12655:      1440      C      I    C-I  2.831071     3349
#> 12656:      1440      F      I    F-I  7.512922     3350
#>                        centroid     direction_dyad
#>                     <sfc_POINT>            <units>
#>     1: POINT (699637.9 5509637)  0.932704118 [rad]
#>     2: POINT (699637.9 5509637) -2.208889158 [rad]
#>     3: POINT (699375.7 5509717) -0.508093298 [rad]
#>     4: POINT (701675.6 5504244) -2.064856591 [rad]
#>     5: POINT (699375.7 5509717)  2.633500732 [rad]
#>    ---                                            
#> 12652: POINT (702960.6 5509447)  2.145953261 [rad]
#> 12653: POINT (702960.7 5509451) -0.262152781 [rad]
#> 12654: POINT (702959.5 5509452) -0.007124986 [rad]
#> 12655: POINT (702960.6 5509447) -0.995639711 [rad]
#> 12656: POINT (702959.5 5509452)  3.134467675 [rad]