Register / look up a direct spatial crosswalk

A registered map short-circuits the atom-layer derivation in geoscale_map() (and thereby recast_geoscale()) for one pair of resolutions – for cases where the exact correspondence is known (hand-audited crosswalks, official concordance tables).

Usage

register_geoscale_map(from, to, map, gs = NULL)

get_geoscale_map(from, to, gs = NULL)

list_geoscale_maps()

Arguments

from, to

The pair the map applies to: geoframe names (with gs naming the object), Geoscale names, or Geoscale objects (their names are used).

map

A data.frame shaped like a geoscale_map() result: the two label columns named after from and to, plus n_from, n_overlap, w and w_from. NULL removes a previously registered map.

gs

Optional Geoscale (or its name) scoping a within-object map, so "state" -> "zone" maps of two different objects do not collide. Cross-object maps need no scope.

Value

Invisibly, the registry key. get_geoscale_map() returns the registered map (or NULL); list_geoscale_maps() a data.frame of registry keys.

Examples

gs <- geoscale_example()
fake <- data.frame(state = "N1", zone = "ZC", n_from = 1L,
                   n_overlap = 1L, w = 1, w_from = 1)
register_geoscale_map("state", "zone", fake, gs = gs)
list_geoscale_maps()
#>                   key
#> 1 example:state->zone
get_geoscale_map("state", "zone", gs = gs)
#>   state zone n_from n_overlap w w_from
#> 1    N1   ZC      1         1 1      1
register_geoscale_map("state", "zone", NULL, gs = gs)  # remove
clear_geoscale_maps()