Fix/bug in lead fusionID fix

[robitalec]

Missing one by = dyadID in recent fix #142 to consider lead fusions causes fusions to mix across observations within dyadIDs. One way to pick them up is looking at the difference between subsequent timegroups within a fusionID:

library(spatsoc)
library(data.table)

DT <- fread(system.file("extdata", "DT.csv", package = "spatsoc"))

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
#>    ---                                                                         
#> 14293:      J 700616.5 5509069 2017-02-28 14:00:54          1       0      1393
#> 14294:      J 700622.6 5509065 2017-02-28 16:00:11          1       0      1394
#> 14295:      J 700657.5 5509277 2017-02-28 18:00:55          1       0      1440
#> 14296:      J 700610.3 5509269 2017-02-28 20:00:48          1       0      1395
#> 14297:      J 700744.0 5508782 2017-02-28 22:00:39          1       0      1396

edges <- edge_dist(
  DT,
  threshold = 100,
  id = 'ID',
  coords = c('X', 'Y'),
  timegroup = 'timegroup',
  returnDist = TRUE,
  fillNA = TRUE
)

dyad_id(edges, 'ID1', 'ID2')
#> Key: <timegroup, ID1>
#>        timegroup    ID1    ID2  distance dyadID
#>            <int> <char> <char>     <num> <char>
#>     1:         1      A   <NA>        NA   <NA>
#>     2:         1      B      G  5.782904    B-G
#>     3:         1      C   <NA>        NA   <NA>
#>     4:         1      D   <NA>        NA   <NA>
#>     5:         1      E      H 65.061671    E-H
#>    ---                                         
#> 22985:      1440      G   <NA>        NA   <NA>
#> 22986:      1440      H   <NA>        NA   <NA>
#> 22987:      1440      I      C  2.831071    C-I
#> 22988:      1440      I      F  7.512922    F-I
#> 22989:      1440      J   <NA>        NA   <NA>

n_min_length <- 3
n_max_missing <- 1
allow_split <- TRUE


fusions <- fusion_id(
  edges,
  threshold = 50,
  n_min_length = n_min_length,
  n_max_missing = n_max_missing,
  allow_split = allow_split
)

check <- fusions[, max(timegroup - shift(timegroup), na.rm = TRUE), by = fusionID]
check[V1 > (n_min_length + n_max_missing)]
#>     fusionID    V1
#>        <int> <int>
#>  1:        1  1339
#>  2:        2   117
#>  3:        6   933
#>  4:        7    46
#>  5:        9   262
#>  6:       13    32
#>  7:       14   217
#>  8:       17  1254
#>  9:       18  1215
#> 10:       19   357
#> 11:       25   417
#> 12:       26   515
#> 13:       36   450
#> 14:       39   460
#> 15:       43   456
#> 16:       48   409
#> 17:       66   528
#> 18:       77   133
#> 19:       78   388
#> 20:       82   468
#> 21:       84   176
#> 22:       86   176
#> 23:       91   347
#> 24:      103   395
#> 25:      110   214
#> 26:      112   344
#> 27:      114   405
#> 28:      116   258
#> 29:      127   136
#> 30:      128   239
#> 31:      129    10
#> 32:      142   283
#> 33:      151    89
#> 34:      157    53
#> 35:      160   131
#> 36:      169   722
#> 37:      170   641
#> 38:      172   299
#> 39:      174   232
#> 40:      175   187
#> 41:      197   342
#> 42:      201   123
#> 43:      202   214
#> 44:      203   120
#> 45:      204   110
#> 46:      207   101
#> 47:      211   154
#> 48:      212    59
#> 49:      229   137
#> 50:      232   140
#> 51:      241   151
#> 52:      246   426
#> 53:      269    16
#> 54:      287    70
#> 55:      288   475
#> 56:      290    54
#> 57:      295   171
#> 58:      299   294
#> 59:      303    73
#> 60:      338   350
#> 61:      350   452
#> 62:      353   348
#> 63:      400   306
#> 64:      408    23
#> 65:      445   309
#> 66:      447   256
#> 67:      466   154
#> 68:      477    98
#> 69:      514    19
#> 70:      545    12
#>     fusionID    V1

^{Created on 2026-03-05 with reprex v2.1.1}