Clean a spatial file and write a normalized copy

Source: R/clean_geo.R

Reads a spatial file (.zip containing a single shapefile, .shp, .gpkg, or .geojson), drops Z/M dimensions, replaces non-ASCII characters in every attribute column, reprojects the geometry to a target CRS and writes the result to a user-provided output path. The output format is determined by the extension of output and may differ from the input format (for example, a .shp can be cleaned and written as .gpkg).

clean_geo(path, output, crs = 4326, encoding = "ISO-8859-1", quiet = FALSE)

Arguments

path

Path to the input spatial file. Must be .zip (containing exactly one shapefile), .shp, .gpkg, or .geojson. Alternatively, an in-memory sf object (for example read and filtered with read_geo()) may be supplied directly; it is cleaned and written to output.

output

Path to the output file. Required. The extension determines the output format and must also be one of .zip, .shp, .gpkg, or .geojson. Existing files at output are overwritten.

crs

Target coordinate reference system passed to sf::st_transform(). Defaults to EPSG:4326 (WGS84).

encoding

Encoding string used when writing shapefile attribute tables (passed as layer_options = "ENCODING=<encoding>"). Applies only to .shp and .zip outputs. Defaults to "ISO-8859-1".

quiet

Logical. If TRUE, suppress progress messages.

Value

Invisibly returns the normalized output path (character).

Details

The input may also be an in-memory sf object, so a layer read and pre-filtered with read_geo() can be written out directly without round-tripping through a file.

This function replaces a standalone batch script that cleaned shapefiles from a client geospatial portal. The non-ASCII replacement step relies on textclean::replace_non_ascii(); textclean lives in Suggests:, so the function stops with an informative error if it is not installed.

See also

Other geo-io: read_gdb(), read_geo(), read_kmz(), read_sf_zip()

Examples

# \donttest{
if (requireNamespace("textclean", quietly = TRUE)) {
  z <- system.file("extdata", "misc_example.zip", package = "misc")
  if (nzchar(z) && file.exists(z)) {
    out <- tempfile(fileext = ".zip")
    clean_geo(z, out)

    out_gpkg <- tempfile(fileext = ".gpkg")
    clean_geo(z, out_gpkg)
  }

  # An in-memory sf object can be passed directly as `path`.
  s <- sf::st_sf(
    id = 1L, name = "caf\u00e9",
    geometry = sf::st_sfc(sf::st_point(c(1, 2)), crs = 4326)
  )
  out_sf <- tempfile(fileext = ".gpkg")
  clean_geo(s, out_sf)
}
#> • Cleaning in-memory sf object
#> • Replacing non-ASCII characters and reprojecting
#> • Writing /tmp/RtmpRkUiJd/file1fc168a7cdf2.gpkg
#> ✔ /tmp/RtmpRkUiJd/file1fc168a7cdf2.gpkg written!
# }