Combine two ID values to create a single ID number

od_id_szudzik(x, y, ordermatters = FALSE)

od_id_max_min(x, y)

od_id_character(x, y)

Arguments

x

a vector of numeric, character, or factor values

y

a vector of numeric, character, or factor values

ordermatters

logical, does the order of values matter to pairing, default = FALSE

Details

In OD data it is common to have many 'oneway' flows from "A to B" and "B to A". It can be useful to group these an have a single ID that represents pairs of IDs with or without directionality, so they contain 'twoway' or bi-directional values.

od_id* functions take two vectors of equal length and return a vector of IDs, which are unique for each combination but the same for twoway flows.

  • the Szudzik pairing function, on two vectors of equal length. It returns a vector of ID numbers.

This function superseeds od_id_order as it is faster on large datasets

See also

Examples

(d <- od_data_sample[2:9, 1:2])
#> # A tibble: 8 × 2 #> geo_code1 geo_code2 #> <chr> <chr> #> 1 E02002361 E02002363 #> 2 E02002361 E02002367 #> 3 E02002361 E02002371 #> 4 E02002361 E02002377 #> 5 E02002361 E02002382 #> 6 E02002361 E02002384 #> 7 E02002361 E02002393 #> 8 E02002363 E02002361
(id <- od_id_character(d[[1]], d[[2]]))
#> [1] "E02002361 E02002363" "E02002361 E02002367" "E02002361 E02002371" #> [4] "E02002361 E02002377" "E02002361 E02002382" "E02002361 E02002384" #> [7] "E02002361 E02002393" "E02002361 E02002363"
#> [1] FALSE FALSE FALSE FALSE FALSE FALSE FALSE TRUE
od_id_szudzik(d[[1]], d[[2]])
#> [1] 5 10 17 26 37 50 65 5
od_id_max_min(d[[1]], d[[2]])
#> [1] 4 7 11 16 22 29 37 4