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Generate point geometries from coordinates

Source: R/ddbs_as_spatial.R
ddbs_as_spatial.Rd

Converts a data frame with coordinate columns into spatial point geometries.

Usage

ddbs_as_spatial(
  x,
  coords = c("lon", "lat"),
  crs = "EPSG:4326",
  conn = NULL,
  name = NULL,
  crs_column = "crs_duckspatial",
  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.

coords

Character vector of length 2 specifying the names of the longitude and latitude columns (or X and Y coordinates). Defaults to c("lon", "lat").

crs

Character or numeric. The Coordinate Reference System (CRS) of the input coordinates. Can be specified as an EPSG code (e.g., "EPSG:4326" or 4326) or a WKT string. Defaults to "EPSG:4326" (WGS84 longitude/latitude).

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

crs_column

Deprecated a character string of length one specifying the column storing the CRS (created automatically by ddbs_write_table). Set to NULL if absent.

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 packages
library(duckspatial)

## create sample data with coordinates
cities_df <- data.frame(
  city = c("Buenos Aires", "Córdoba", "Rosario"),
  lon = c(-58.3816, -64.1811, -60.6393),
  lat = c(-34.6037, -31.4201, -32.9468),
  population = c(3075000, 1391000, 1193605)
)

# option 1: convert data frame to sf object
cities_ddbs <- ddbs_as_spatial(cities_df)

# specify custom coordinate column names
cities_df2 <- data.frame(
  city = c("Mendoza", "Tucumán"),
  longitude = c(-68.8272, -65.2226),
  latitude = c(-32.8895, -26.8241)
)

ddbs_as_spatial(cities_df2, coords = c("longitude", "latitude"))


## option 2: convert table in duckdb to spatial table

# create a duckdb connection and write data
conn <- duckspatial::ddbs_create_conn()
DBI::dbWriteTable(conn, "cities_tbl", cities_df, overwrite = TRUE)

# convert to spatial table in database
ddbs_as_spatial(
    x = "cities_tbl",
    conn = conn,
    name = "cities_spatial",
    overwrite = TRUE
)

# read the spatial table
ddbs_read_table(conn, "cities_spatial")
} # }