Geometry WKB/WKT conversion

g_wk2wk() converts geometries between Well Known Binary (WKB) and Well Known Text (WKT) formats. A geometry given as a raw vector of WKB will be converted to a WKT string, while a geometry given as a WKT string will be converted to a WKB raw vector. Input may also be a list of WKB raw vectors or a character vector of WKT strings.

Usage

g_wk2wk(geom, as_iso = FALSE, byte_order = "LSB")

Arguments

geom

Either a raw vector of WKB or list of raw vectors to convert to WKT, or a character vector containing one or more WKT strings to convert to WKB.

as_iso

Logical scalar. TRUE to export as ISO WKB/WKT (ISO 13249 SQL/MM Part 3), or FALSE (the default) to export as "Extended WKB/WKT" (see Note).

byte_order

Character string specifying the byte order when converting to WKB. One of "LSB" (the default) or "MSB" (uncommon).

Value

For input of a WKB raw vector or list of raw vectors, returns a character vector of WKT strings, with length of the returned vector equal to the number of input raw vectors. For input of a single WKT string, returns a raw vector of WKB. For input of a character vector containing more than one WKT string, returns a list of WKB raw vectors, with length of the returned list equal to the number of input strings.

Note

With as_iso = FALSE (the default), geometries are exported as extended dimension (Z) WKB/WKT for types Point, LineString, Polygon, MultiPoint, MultiLineString, MultiPolygon and GeometryCollection. For other geometry types, it is equivalent to ISO.

When the return value is a list of WKB raw vectors, an element in the returned list will contain NA if the corresponding input string was NA or empty ("").

When input is a list of WKB raw vectors, a corresponding element in the returned character vector will be an empty string ("") if the input was a raw vector of length 0 (raw(0)). If an input list element is not a raw vector, then the corresponding element in the returned character vector will be NA.

See also

GEOS reference for geometry formats:
https://libgeos.org/specifications/

Examples

wkt <- "POINT (-114 47)"
wkb <- g_wk2wk(wkt)
print(wkb)
#>  [1] 01 01 00 00 00 00 00 00 00 00 80 5c c0 00 00 00 00 00 80 47 40
g_wk2wk(wkb)
#> [1] "POINT (-114 47)"