ddbs_simplify: Simplify geometries

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

Simplify geometries

Description

Reduces the complexity of geometries by removing unnecessary vertices while preserving the overall shape.

Usage

ddbs_simplify(
  x,
  tolerance = 0,
  preserve_topology = FALSE,
  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.
tolerance	Tolerance distance for simplification. Larger values result in more simplified geometries.
preserve_topology	If FALSE, uses the Douglas-Peucker algorithm, which reduces the vertices by removing points that are within a given distance. If TRUE, uses a topology-preserving variant of Douglas-Peucker that guarantees the output geometry remains valid (slower).
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 package
library(duckspatial)

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

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

## store in duckdb
ddbs_write_vector(conn, countries_ddbs, "countries")

## simplify with tolerance of 0.01
ddbs_simplify("countries", tolerance = 0.01, conn = conn)

## simplify without using a connection
ddbs_simplify(countries_ddbs, tolerance = 0.01)

## End(Not run)

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