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Retrieve IFN regional layers by intersecting an area

get_ifn.Rd

Downloads (if necessary), caches and extracts IFN regional layers intersecting a given area of interest.

Usage

get_ifn(x, key, cache = NULL)

Arguments

x

An sf object defining the input area of interest.

key

A character string specifying the IFN regional dataset to use. Must be one of get_keys("ifn"):

  • "ser": sylvo-ecoregions

  • "ser_ar": sylvo-ecoregions (aggregated regions)

  • "rfn": region forestiere nationale

  • "rfd": region forestiere departementale

  • "zp": zones de production

cache

A character string defining the cache directory. Defaults to a package-specific cache directory created with tools::R_user_dir("Rsequoia2", which = "cache").

Value

An sf object containing the region features intersecting x. Returns NULL if no region intersects the input geometry.

Details

The function retrieves official IGN regional datasets provided as shapefiles in Lambert-93 projection. Downloaded archives are stored locally and reused on subsequent calls.

The regional layer is automatically reprojected to match the coordinate reference system of x before computing spatial intersections.

Only features intersecting the input geometry are returned. No geometry modification (e.g. clipping) is applied.