Calculates the centroid of geometries — ddbs

Calculates the centroids of geometries from a DuckDB table using the spatial extension. Returns the result as an sf object or creates a new table in the database.

Usage

ddbs_centroid(
  conn,
  x,
  name = NULL,
  crs = NULL,
  crs_column = "crs_duckspatial",
  overwrite = FALSE
)

Arguments

conn: a connection object to a DuckDB database
x: a table with a geometry column within the DuckDB database
name: a character string of length one specifying the name of the table, or a character string of length two specifying the schema and table names. If it's NULL (the default), it will return the result as an sf object
crs: the coordinates reference system of the data. Specify if the data doesn't have a crs_column, and you know the CRS
crs_column: a character string of length one specifying the column storing the CRS (created automatically by ddbs_write_vector). Set to NULL if absent
overwrite: whether to overwrite the existing table if it exists. Ignored when name is NULL

Value

an sf object or TRUE (invisibly) for table creation

Examples

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

## database setup
conn <- dbConnect(duckdb())
ddbs_install(conn)
ddbs_load(conn)

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

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

## centroid
ddbs_centroid(conn, "argentina")
} # }