ddbs_generate_points: Generate random points within bounding boxes of geometries

In duckspatial: R Interface to 'DuckDB' Database with Spatial Extension

Generate random points within bounding boxes of geometries

Description

Creates random points within the bounding box of each geometry, which may fall outside the geometry itself.

Usage

ddbs_generate_points(
  x,
  n,
  seed = NULL,
  conn = NULL,
  name = NULL,
  mode = NULL,
  overwrite = FALSE,
  quiet = FALSE
)

Arguments

x	Input spatial data. Can be: A duckspatial_df object (lazy spatial data frame via dbplyr) An sf object A tbl_lazy from dbplyr A character string naming a table/view in conn Data is returned from this object.
n	Number of random points to generate within each geometry
seed	A number for the random number generator
conn	A connection object to a DuckDB database. If NULL, the function runs on a temporary 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 NULL (the default), the function returns the result as an sf object
mode	Character. Controls the return type. Options: "duckspatial" (default): Lazy spatial data frame backed by dbplyr/DuckDB "sf": Eagerly collected sf object (uses memory) Can be set globally via ddbs_options(mode = "...") or per-function via this argument. Per-function overrides global setting.
overwrite	Boolean. whether to overwrite the existing table if it exists. Defaults to FALSE. This argument is ignored when name is NULL.
quiet	A logical value. If TRUE, suppresses any informational messages. Defaults to FALSE.

Value

Depends on the mode argument (or global preference set by ddbs_options):

• duckspatial (default): A duckspatial_df (lazy spatial data frame) backed by dbplyr/DuckDB.

• sf: An eagerly collected object in R memory, that will return the same data type as the sf equivalent (e.g. sf or units vector).

When name is provided, the result is also written as a table or view in DuckDB and the function returns TRUE (invisibly).

Examples

## Not run: 
## load packages
library(duckspatial)

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

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

## store in duckdb
ddbs_write_table(conn, argentina_ddbs, "argentina")

## generate 100 random points within each geometry
ddbs_generate_points("argentina", n = 100, conn)

## generate points without using a connection
ddbs_generate_points(argentina_ddbs, n = 100)

## End(Not run)

duckspatial documentation built on June 22, 2026, 9:08 a.m.