filter_gadm_province_spatial: filter gadm province spatial

In basifoR: Retrieval and Processing of the Spanish National Forest Inventory

filter gadm province spatial

Description

Filter a Spanish GADM layer using a strict province identity resolver.

Usage

filter_gadm_province_spatial(adm, 
    prov, province_table = NULL, 
    level = attr(adm, 
        "gadm_level", 
        exact = TRUE), 
    strict = TRUE)

Arguments

adm	An sf object returned by gadm_spatial() or a user-provided GADM-like boundary layer.
prov	Province code or name. Numeric codes are matched directly. Non-numeric names are resolved against a clean GADM-oriented province-name lookup and, only as a last resort, against basifoR's procods code resolver.
province_table	Optional province lookup table used only by the fallback basifoR code resolver. It is not used as a list of GADM aliases.
level	GADM level of adm. Level 2 returns one province. Higher levels return features whose NAME_2 belongs to the province, for example municipalities inside a province.
strict	logical. If TRUE, level-2 matches must return one province. This prevents false matches from short aliases such as "ZA", which could match both Zamora and Zaragoza.

Details

This function deliberately does not use all aliases stored in procods for GADM filtering. The procods table can contain operational curation and province redirections used by basifoR/MITECO workflows. Boundary filtering needs geographic province identity. Therefore procods is used, at most, to resolve the input to a numeric province code; the final GADM match uses exact normalized matching against NAME_2 and a clean province-name lookup. This avoids false matches such as Zamora also selecting Zaragoza through a short alias.

Value

A filtered sf object. For GADM level 2, the object should contain one province feature. For higher levels, the object may contain several subprovince features. Attributes store the resolved province code, GADM name, and aliases tested. Exact normalized matching only. Do not use grepl() with short aliases.

Author(s)

Wilson Lara [aut, cre] (ORCID: <https://orcid.org/0000-0003-3527-1380>), Cristobal Ordonez [aut] (ORCID: <https://orcid.org/0000-0001-5354-3760>), Aitor Vázquez-Veloso [aut] (ORCID: <https://orcid.org/0000-0003-0227-506X>), Felipe Bravo [aut] (ORCID: <https://orcid.org/0000-0001-7348-6695>)

See Also

gadm_spatial, readNFI_spatial

Examples

if (interactive()) {
    adm <- gadm_spatial("ESP", level = 2, path = tempdir())
    zamora <- filter_gadm_province_spatial(adm, 49)
    nrow(zamora)
}

basifoR documentation built on Aug. 26, 2026, 9:06 a.m.