Correspondence between two administrative vintages

Which units of one vintage correspond to which of another, and how each changed. Derived from shared territory rather than stored, so any pair of vintages works and nothing goes stale when a new one is added.

Usage

pt_crosswalk(
  from = "2013",
  to = NULL,
  level = c("freguesia", "municipio", "distrito")
)

Arguments

from, to

Administrative vintages: "2001", "2011", "2013" or "2025". from defaults to "2013"; leave to out for the newest ("2025").

level

Which units to relate. Only "freguesia" changes across these vintages; "municipio" and "distrito" are included for completeness.

Value

A data.frame with one row per corresponding pair: from, to, name_from, name_to, relation.

Codes are vintage-local

A DTMNFR identifies a unit within its own vintage only. None of the 302 freguesias restored in 2025 reused its pre-2013 code, so this table — not string comparison — is the only safe way to relate codes across vintages.

Relations

relation is computed from the correspondence itself:

unchanged

same territory, same code, same name.

renamed

same territory and code, different name.

renumbered

same territory, different code. Colos kept its territory across the 2025 reform and changed only its code (021118 → 021124).

merged

several from units became one — the 2013 uniões.

split

one from unit became several — the 2025 reposição.

See also

pt_recode() to carry values across vintages, pt_registry for the units themselves.

Examples

x <- pt_crosswalk("2013", "2025")
table(x$relation)
#> 
#> renumbered      split  unchanged 
#>          1        301       2957 

# what became of the 2013 "030882" code
x[x$from == "030882", ]
#>       from     to                                 name_from   name_to relation
#> 490 030882 030895 União das freguesias de Conde e Gandarela     Conde    split
#> 492 030882 030897 União das freguesias de Conde e Gandarela Gandarela    split