Convert geometries to Well-Known Text (WKT) format

Converts spatial geometries to their Well-Known Text (WKT) representation. This function wraps DuckDB's ST_AsText spatial function.

Usage

ddbs_as_text(x, conn = NULL, quiet = FALSE)

Arguments

x

An sf spatial object. Alternatively, it can be a string with the name of a table with geometry column within the DuckDB database conn. Data is returned from this object.

conn

A connection object to a DuckDB database. If NULL, the function runs on a temporary DuckDB database.

quiet

A logical value. If TRUE, suppresses any informational messages. Defaults to FALSE.

Value

A character vector containing WKT representations of the geometries

Details

Well-Known Text (WKT) is a text markup language for representing vector geometry objects. This function is useful for exporting geometries in a portable text format that can be used with other spatial tools and databases.

Examples

if (FALSE) { # \dontrun{
## load packages
library(duckspatial)
library(sf)

# create a duckdb database in memory (with spatial extension)
conn <- ddbs_create_conn(dbdir = "memory")

## read data
argentina_sf <- st_read(system.file("spatial/argentina.geojson", package = "duckspatial"))

## store in duckdb
ddbs_write_vector(conn, argentina_sf, "argentina")

## convert geometries to WKT
wkt_text <- ddbs_as_text(conn = conn, "argentina")

## convert without using a connection
wkt_text <- ddbs_as_text(argentina_sf)
} # }