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Spatial predicate constructors

Source: R/predicates.R
spatial_predicates.Rd

These functions create spatial predicates used by get_wfs() to filter features based on their spatial relationship with a reference geometry.

Usage

intersects()

within()

disjoint()

contains()

touches()

crosses()

overlaps()

equals()

bbox()

dwithin(distance, units = "meters")

beyond(distance, units = "meters")

relate(pattern)

Arguments

distance

Numeric distance value (single value).

units

Distance units supported by the WFS server (e.g. "meters", "kilometers").

pattern

A 9-character DE-9IM pattern string.

Value

A spatial predicate object (used internally by get_wfs()).

Details

Predicates describe how geometries should be compared (e.g. intersection, containment, distance-based relations). Users should not construct predicates manually; instead, use the helper functions listed below.

  • bbox(): Select features intersecting the bounding box of the reference geometry.

  • intersects(): Select features whose geometry intersects the reference geometry.

  • disjoint(): Select features whose geometry intersects the reference geometry.

  • contains(): Select features that completely contain the reference geometry.

  • within(): Select features completely within the reference geometry.

  • touches(): Select features that touch the reference geometry at the boundary.

  • crosses(): Select features that cross the reference geometry.

  • overlaps(): Select features that partially overlap the reference geometry.

  • equals(): Select features geometrically equal to the reference geometry.

  • dwithin(distance, units): Select features within a given distance of the reference geometry.

  • beyond(distance, units): Select features farther than a given distance from the reference geometry.

  • relate(pattern): Select features matching a DE-9IM spatial relationship pattern.

See also

get_wfs()

Examples

intersects()
#> $type
#> [1] "intersects"
#> 
bbox()
#> $type
#> [1] "bbox"
#> 
dwithin(50, "meters")
#> $type
#> [1] "dwithin"
#> 
#> $distance
#> [1] 50
#> 
#> $units
#> [1] "meters"
#> 
beyond(100, "meters")
#> $type
#> [1] "beyond"
#> 
#> $distance
#> [1] 100
#> 
#> $units
#> [1] "meters"
#> 
relate("T*F**F***")
#> $type
#> [1] "relate"
#> 
#> $pattern
#> [1] "T*F**F***"
#>