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Extent and coordinate reference system without collecting

Source: R/sf_methods.R
overture_sf_methods.Rd

sf::st_bbox() and sf::st_crs() methods for lazy overture_call tables, so you can read a query's extent and coordinate reference system straight from DuckDB, without pulling the rows into R with collect().

Usage

# S3 method for class 'overture_call'
st_crs(x, ...)

# S3 method for class 'overture_call'
st_bbox(obj, ...)

Arguments

...

Unused, for compatibility with the generics.

obj, x

An overture_call object, as returned by open_curtain().

Value

st_bbox() returns an sf::st_bbox() object; st_crs() returns an sf::st_crs() object.

Details

st_bbox() runs one ST_Extent_Agg() query over the geometry column. st_crs() reads the coordinate reference system from DuckDB's typed GEOMETRY column (for example GEOMETRY('OGC:CRS84') on duckdb >= 1.5), falling back to EPSG:4326, which is what Overture stores.

Examples

if (FALSE) { # interactive()
bbox <- c(xmin = -120.5, ymin = 35.5, xmax = -120.0, ymax = 36.0)
buildings <- open_curtain("building", bbox)
sf::st_crs(buildings)
sf::st_bbox(buildings)
}