| od_id {stplanr} | R Documentation |
Combine two ID values to create a single ID number
Description
Combine two ID values to create a single ID number
Usage
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
Other od:
od2line(),
od2odf(),
od_aggregate_from(),
od_aggregate_to(),
od_coords(),
od_coords2line(),
od_id_order(),
od_oneway(),
od_to_odmatrix(),
odmatrix_to_od(),
points2flow(),
points2odf()
Examples
(d <- od_data_sample[2:9, 1:2])
(id <- od_id_character(d[[1]], d[[2]]))
duplicated(id)
od_id_szudzik(d[[1]], d[[2]])
od_id_max_min(d[[1]], d[[2]])