Convert foreign geometry object to an sfc object

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

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

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

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

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

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

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

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

st_as_sfc(x, ...)

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

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

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

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

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

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

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	integer or character; coordinate reference system for the
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

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
#> bbox:           xmin: 181072 ymin: 333611 xmax: 181072 ymax: 333611
#> CRS:            EPSG:28992
#> 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
#> bbox:           xmin: 181072 ymin: 333611 xmax: 181072 ymax: 333611
#> CRS:            EPSG:28992
#> 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
#> bbox:           xmin: 0 ymin: 1 xmax: 0 ymax: 1
#> CRS:            EPSG:4326
#> POINT (0 1)
st_as_sfc("SRID=3978;LINESTRING(1663106 -105415,1664320 -104617)")
#> Geometry set for 1 feature 
#> geometry type:  LINESTRING
#> dimension:      XY
#> bbox:           xmin: 1663106 ymin: -105415 xmax: 1664320 ymax: -104617
#> CRS:            EPSG:3978
#> LINESTRING (1663106 -105415, 1664320 -104617)