Convert foreign geometry object to an sfc object

Usage

# S3 method for class 'pq_geometry'
st_as_sfc(
  x,
  ...,
  EWKB = TRUE,
  spatialite = FALSE,
  pureR = FALSE,
  crs = NA_crs_
)

# S3 method for class 'list'
st_as_sfc(x, ..., crs = NA_crs_)

# S3 method for class 'blob'
st_as_sfc(x, ...)

# S3 method for class 'bbox'
st_as_sfc(x, ...)

# S3 method for class 'WKB'
st_as_sfc(
  x,
  ...,
  EWKB = FALSE,
  spatialite = FALSE,
  pureR = FALSE,
  crs = NA_crs_
)

# S3 method for class 'raw'
st_as_sfc(x, ...)

# S3 method for class 'character'
st_as_sfc(x, crs = NA_integer_, ..., GeoJSON = FALSE)

# S3 method for class 'factor'
st_as_sfc(x, ...)

st_as_sfc(x, ...)

# S3 method for class 'SpatialPoints'
st_as_sfc(x, ..., precision = 0)

# S3 method for class 'SpatialPixels'
st_as_sfc(x, ..., precision = 0)

# S3 method for class 'SpatialMultiPoints'
st_as_sfc(x, ..., precision = 0)

# S3 method for class 'SpatialLines'
st_as_sfc(x, ..., precision = 0, forceMulti = FALSE)

# S3 method for class 'SpatialPolygons'
st_as_sfc(x, ..., precision = 0, forceMulti = FALSE)

# S3 method for class 'map'
st_as_sfc(x, ...)

# S3 method for class 's2_geography'
st_as_sfc(
  x,
  ...,
  crs = st_crs(4326),
  endian = match(.Platform$endian, c("big", "little")) - 1L
)

Arguments

x: object to convert
...: further arguments
EWKB: logical; if TRUE, parse as EWKB (extended WKB; PostGIS: ST_AsEWKB), otherwise as ISO WKB (PostGIS: ST_AsBinary)
spatialite: logical; if TRUE, WKB is assumed to be in the spatialite dialect, see https://www.gaia-gis.it/gaia-sins/BLOB-Geometry.html; this is only supported in native endian-ness (i.e., files written on system with the same endian-ness as that on which it is being read).
pureR: logical; if TRUE, use only R code, if FALSE, use compiled (C++) code; use TRUE when the endian-ness of the binary differs from the host machine (.Platform$endian).
crs: coordinate reference system to be assigned; object of class crs
GeoJSON: logical; if TRUE, try to read geometries from GeoJSON text strings geometry, see st_crs()
precision: precision value; see st_as_binary
forceMulti: logical; if TRUE, force coercion into MULTIPOLYGON or MULTILINE objects, else autodetect
endian: integer; 0 or 1: defaults to the endian of the native machine

Details

When converting from WKB, the object x is either a character vector such as typically obtained from PostGIS (either with leading "0x" or without), or a list with raw vectors representing the features in binary (raw) form.

If x is a character vector, it should be a vector containing well-known-text, or Postgis EWKT or GeoJSON representations of a single geometry for each vector element.

If x is a factor, it is converted to character.

Examples

wkb = structure(list("01010000204071000000000000801A064100000000AC5C1441"), class = "WKB")
st_as_sfc(wkb, EWKB = TRUE)
#> Geometry set for 1 feature 
#> Geometry type: POINT
#> Dimension:     XY
#> Bounding box:  xmin: 181072 ymin: 333611 xmax: 181072 ymax: 333611
#> Projected CRS: Amersfoort / RD New
#> POINT (181072 333611)
wkb = structure(list("0x01010000204071000000000000801A064100000000AC5C1441"), class = "WKB")
st_as_sfc(wkb, EWKB = TRUE)
#> Geometry set for 1 feature 
#> Geometry type: POINT
#> Dimension:     XY
#> Bounding box:  xmin: 181072 ymin: 333611 xmax: 181072 ymax: 333611
#> Projected CRS: Amersfoort / RD New
#> POINT (181072 333611)
st_as_sfc(st_as_binary(st_sfc(st_point(0:1)))[[1]], crs = 4326)
#> Geometry set for 1 feature 
#> Geometry type: POINT
#> Dimension:     XY
#> Bounding box:  xmin: 0 ymin: 1 xmax: 0 ymax: 1
#> Geodetic CRS:  WGS 84
#> POINT (0 1)
st_as_sfc("SRID=3978;LINESTRING(1663106 -105415,1664320 -104617)")
#> Geometry set for 1 feature 
#> Geometry type: LINESTRING
#> Dimension:     XY
#> Bounding box:  xmin: 1663106 ymin: -105415 xmax: 1664320 ymax: -104617
#> Projected CRS: NAD83 / Canada Atlas Lambert
#> LINESTRING (1663106 -105415, 1664320 -104617)