Extract plain sf geometry from an exploded layout

Converts an exploded_map or grouped_exploded_map back to a plain sf data frame so the layout can flow into downstream GIS work (writing files, spatial joins, further sf analysis) without carrying the layout metadata.

Usage

as_sf(layout, which = c("exploded", "original"))

Arguments

layout: An exploded_map or grouped_exploded_map object.
which: Which stored geometry layer to return. For exploded_map: "exploded" (default) or "original". For grouped_exploded_map: "grouped" (default), "local", or "original".

Value

A plain sf object with the selected geometry layer active. All attribute columns and the CRS are kept as stored. Layout metadata (stats, params, plots, refinement, diagnostics, anchors) is dropped. The "exploded"/"grouped" layers carry the displaced geometries; "original" carries the input geometries.

Examples

# \donttest{
sq <- function(xmin, ymin, size = 1) {
  sf::st_polygon(list(matrix(
    c(xmin, ymin, xmin + size, ymin, xmin + size, ymin + size,
      xmin, ymin + size, xmin, ymin),
    ncol = 2, byrow = TRUE
  )))
}
x <- sf::st_sf(
  id = c("a1", "a2", "b1", "b2"),
  region = c("A", "A", "B", "B"),
  geometry = sf::st_sfc(sq(0, 0), sq(2, 0), sq(10, 0), sq(12, 0), crs = 3857)
)
layout <- explode_sf(x, region_col = "region", plot = FALSE, quiet = TRUE)

# Displaced geometries, ready for st_write() or further analysis
exp_sf <- as_sf(layout)
sf::st_crs(exp_sf)
#> Coordinate Reference System:
#>   User input: EPSG:3857 
#>   wkt:
#> PROJCRS["WGS 84 / Pseudo-Mercator",
#>     BASEGEOGCRS["WGS 84",
#>         ENSEMBLE["World Geodetic System 1984 ensemble",
#>             MEMBER["World Geodetic System 1984 (Transit)"],
#>             MEMBER["World Geodetic System 1984 (G730)"],
#>             MEMBER["World Geodetic System 1984 (G873)"],
#>             MEMBER["World Geodetic System 1984 (G1150)"],
#>             MEMBER["World Geodetic System 1984 (G1674)"],
#>             MEMBER["World Geodetic System 1984 (G1762)"],
#>             MEMBER["World Geodetic System 1984 (G2139)"],
#>             ELLIPSOID["WGS 84",6378137,298.257223563,
#>                 LENGTHUNIT["metre",1]],
#>             ENSEMBLEACCURACY[2.0]],
#>         PRIMEM["Greenwich",0,
#>             ANGLEUNIT["degree",0.0174532925199433]],
#>         ID["EPSG",4326]],
#>     CONVERSION["Popular Visualisation Pseudo-Mercator",
#>         METHOD["Popular Visualisation Pseudo Mercator",
#>             ID["EPSG",1024]],
#>         PARAMETER["Latitude of natural origin",0,
#>             ANGLEUNIT["degree",0.0174532925199433],
#>             ID["EPSG",8801]],
#>         PARAMETER["Longitude of natural origin",0,
#>             ANGLEUNIT["degree",0.0174532925199433],
#>             ID["EPSG",8802]],
#>         PARAMETER["False easting",0,
#>             LENGTHUNIT["metre",1],
#>             ID["EPSG",8806]],
#>         PARAMETER["False northing",0,
#>             LENGTHUNIT["metre",1],
#>             ID["EPSG",8807]]],
#>     CS[Cartesian,2],
#>         AXIS["easting (X)",east,
#>             ORDER[1],
#>             LENGTHUNIT["metre",1]],
#>         AXIS["northing (Y)",north,
#>             ORDER[2],
#>             LENGTHUNIT["metre",1]],
#>     USAGE[
#>         SCOPE["Web mapping and visualisation."],
#>         AREA["World between 85.06°S and 85.06°N."],
#>         BBOX[-85.06,-180,85.06,180]],
#>     ID["EPSG",3857]]

# The untouched input geometries
orig_sf <- as_sf(layout, which = "original")
# }