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Computes a Voronoi diagram from point geometries

Source: R/ddbs_ops_unary.R
ddbs_voronoi.Rd

Returns a Voronoi diagram (Thiessen polygons) from a collection of points. Each polygon represents the region closer to one point than to any other point in the set. This function only works with MULTIPOINT geometries.

Usage

ddbs_voronoi(
  x,
  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.

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), no table is written and the result is returned as a duckspatial_df or sf object, depending on mode

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

if (FALSE) { # \dontrun{
## load package
library(duckspatial)

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

## create some points, and combine them to MULTIPOINT
set.seed(42)
n <- 1000
points_ddbs <- data.frame(
    id = 1:n,
    x = runif(n, min = -20, max = 20),
    y = runif(n, min = -20, max = 02)
) |>
  ddbs_as_spatial(coords = c("x", "y"), crs = 4326) |> 
  ddbs_combine()

## create voronoi diagrama
ddbs_voronoi(points_ddbs)
} # }