geom_to_bng {osbng} | R Documentation |
Spatial index for geometries
Description
Returns a set of BNG Reference objects given a geometry and a specified resolution.
Usage
geom_to_bng(geom, resolution, ...)
## S3 method for class 'geos_geometry'
geom_to_bng(geom, resolution, ...)
## S3 method for class 'sf'
geom_to_bng(geom, resolution, ...)
## S3 method for class 'sfc'
geom_to_bng(geom, resolution, ...)
geom_to_bng_intersection(
geom,
resolution,
format = c("geos", "sf", "wkt"),
...
)
## S3 method for class 'geos_geometry'
geom_to_bng_intersection(
geom,
resolution,
format = c("geos", "sf", "wkt"),
...
)
## S3 method for class 'sf'
geom_to_bng_intersection(
geom,
resolution,
format = c("geos", "sf", "wkt"),
...
)
## S3 method for class 'sfc'
geom_to_bng_intersection(
geom,
resolution,
format = c("geos", "sf", "wkt"),
...
)
Arguments
geom |
geometry object of type |
resolution |
spatial resolution of the BNG cell expressed in string or integer values |
... |
additional parameters. Not currently used. |
format |
character indicating the type of geometry object to return.
Default is "geos" while "sf" returns a geometry object of class |
Details
The BNG Reference objects returned represent the grid squares intersected by the input geometry. BNG Reference objects are de-duplicated in cases where two or more parts of a multi-part geometry intersect the same grid square.
Unlike geom_to_bng
which only returns BNG Reference objects
representing the grid squares intersected by the input geometry,
geom_to_bng_intersection
returns list objects that store the
intersection between the input geometry and the grid square geometries.
These functions are useful for spatial indexing and aggregation of geometries
against the BNG. For geometry decomposition by the BNG index system, use
geom_to_bng_intersection instead
.
Value
geom_to_bng
: list of vectors of BNGReference
objects where the
number of items in the list equal length(geom)
.
geom_to_bng_intersection
: list of nested lists with
length(geom)
. Each nested list contains three named items:
"BNGReference" -
BNGReference
objects representing the grid squares corresponding to the decomposition."is_core" - logical vector indicating whether the grid square geometry is entirely contained by the input geometry. This is relevant for Polygon geometries and helps distinguish between "core" (fully inside) and "edge" (partially overlapping) grid squares.
"geom" - The geometry representing the intersection between the input geometry and the grid square. This can one of a number of geometry types depending on the overlap. When "is_core" is
TRUE
, "geom" is the same as the grid square geometry.
See Also
geom_to_bng_intersection_explode()
Examples
geom_to_bng(geos::geos_make_point(430000, 110000), "100km")
geom_to_bng(geos::geos_make_linestring(c(430000, 430010, 430010), c(110000,
110000, 110010)), "5m")
geom_to_bng_intersection(geos::geos_make_point(430000, 110000), "100km")
geom_to_bng_intersection(geos::geos_make_linestring(c(430000, 430010,
430010), c(110000, 110000, 110010)), "5m")
geom_to_bng_intersection(geos::geos_make_polygon(c(375480.64511692,
426949.67604058, 465166.20199588, 453762.88376729, 393510.2158297,
375480.64511692), c(144999.23691181, 160255.02751493, 153320.57724078,
94454.79935802, 91989.21703833, 144999.23691181)), "50km")