Spatial Filter — ddbs_filter • duckspatial

Filters data spatially based on a spatial predicate

Usage

ddbs_filter(
  conn,
  x,
  y,
  name = NULL,
  predicate = "intersection",
  crs = NULL,
  crs_column = "crs_duckspatial",
  overwrite = FALSE
)

Arguments

conn: a connection object to a DuckDB database
x: a table with geometry column within the DuckDB database. Data is returned from this object
y: a table with 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
predicate: geometry predicate to use for filtering the data
crs: the coordinates reference system of the data. Specify if the data doesn't have 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
countries_sf <- st_read(system.file("spatial/countries.geojson", package = "duckspatial"))
argentina_sf <- st_read(system.file("spatial/argentina.geojson", package = "duckspatial"))

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

## filter countries touching argentina
ddbs_filter(conn, "countries", "argentina", predicate = "touches")
} # }