duckspatial (version 0.9.0)

ddbs_distance: Returns the distance between two geometries

Description

Returns the planar or haversine distance between two geometries, and returns a data.frame object or creates a new table in a DuckDB database.

Usage

ddbs_distance(x, y, dist_type = "haversine", conn = NULL, quiet = FALSE)

Value

A data.frame object or TRUE (invisibly) for table creation

Arguments

x

An sf spatial object. Alternatively, it can be a string with the name of a table with geometry column within the DuckDB database conn. Data is returned from this object.

y

An sf spatial object. Alternatively, it can be a string with the name of a table with geometry column within the DuckDB database conn.

dist_type

String. One of c("planar", "haversine"). Defaults to "haversine" and returns distance in meters, but the input is expected to be in WGS84 (EPSG:4326) coordinates. The option "haversine" only accepts POINT geometries. When dist_type = "planar", distances estimates are in the same unit as the coordinate reference system (CRS) of the input.

conn

A connection object to a DuckDB database. If NULL, the function runs on a temporary DuckDB database.

quiet

A logical value. If TRUE, suppresses any informational messages. Defaults to FALSE.

Examples

if (FALSE) {
# load packages
library(duckspatial)
library(sf)

# create points data
n <- 10
points_sf <- data.frame(
    id = 1:n,
    x = runif(n, min = -180, max = 180),
    y = runif(n, min = -90, max = 90)
) |>
    sf::st_as_sf(coords = c("x", "y"), crs = 4326)

# option 1: passing sf objects
output1 <- duckspatial::ddbs_distance(
    x = points_sf,
    y = points_sf,
    dist_type = "haversine"
)

head(output1)


## option 2: passing the names of tables in a duckdb db and output as sf

# creates a duckdb
conn <- duckspatial::ddbs_create_conn()

# write sf to duckdb
ddbs_write_vector(conn, points_sf, "points", overwrite = TRUE)

output2 <- ddbs_distance(
    conn = conn,
    x = "points",
    y = "points",
    dist_type = "haversine"
)
head(output2)

}