spatial_join
Usage
spatial_join(
x,
y,
by = c("st_intersects", "st_within", "st_dwithin", "st_touches", "st_contains",
"st_containsproperly", "st_covers", "st_overlaps", "st_crosses", "st_equals",
"st_disjoint"),
args = "",
join = "left",
tblname = tmp_tbl_name(),
conn = cached_connection()
)Arguments
- x
a duckdb table with a spatial geometry column called "geom"
- y
a duckdb table with a spatial geometry column called "geom"
- by
A spatial join function, see details.
- args
additional arguments to join function (e.g. distance for st_dwithin)
- join
JOIN type (left, right, inner, full)
- tblname
name for the temporary view
- conn
the duckdb connection (imputed by duckdbfs by default, must be shared across both tables)
Value
a (lazy) view of the resulting table. Users can continue to operate on using dplyr operations and call to_st() to collect this as an sf object.
Details
Possible spatial joins include:
| Function | Description |
| st_intersects | Geometry A intersects with geometry B |
| st_disjoint | The complement of intersects |
| st_within | Geometry A is within geometry B (complement of contains) |
| st_dwithin | Geometries are within a specified distance, expressed in the same units as the coordinate reference system. |
| st_touches | Two polygons touch if the that have at least one point in common, even if their interiors do not touch. |
| st_contains | Geometry A entirely contains to geometry B. (complement of within) |
| st_containsproperly | stricter version of st_contains (boundary counts as external) |
| st_covers | geometry B is inside or on boundary of A. (A polygon covers a point on its boundary but does not contain it.) |
| st_overlaps | geometry A intersects but does not completely contain geometry B |
| st_equals | geometry A is equal to geometry B |
| st_crosses | Lines or points in geometry A cross geometry B. |
All though SQL is not case sensitive, this function expects only lower case names for "by" functions.
Examples
if (FALSE) { # interactive()
# note we can read in remote data in a variety of vector formats:
countries <-
paste0("/vsicurl/",
"https://github.com/cboettig/duckdbfs/",
"raw/spatial-read/inst/extdata/world.gpkg") |>
open_dataset(format = "sf")
cities <-
paste0("/vsicurl/https://github.com/cboettig/duckdbfs/raw/",
"spatial-read/inst/extdata/metro.fgb") |>
open_dataset(format = "sf")
countries |>
dplyr::filter(iso_a3 == "AUS") |>
spatial_join(cities)
}