ohsome_extract_elements: Extract OSM elements

Description

Create an ohsome_query object for OSM element extraction

Usage

ohsome_extract_elements(
  boundary = NULL,
  geometryType = c("centroid", "bbox", "geometry"),
  time = NULL,
  properties = NULL,
  clipGeometry = TRUE,
  ...
)
ohsome_elements_bbox(boundary = NULL, ...)
ohsome_elements_centroid(boundary = NULL, ...)
ohsome_elements_geometry(boundary = NULL, ...)

Value

An ohsome_query object. The object can be sent to the ohsome API with ohsome_post(). It consists of the following elements:

url: The URL of the endpoint.
encode: The way the information is encoded and then posted to the ohsome API. Set as "form".
body: The parameters of the query such as format, filter or bpolys.

Arguments

boundary

Bounding geometries specified by WGS84 coordinates in the order lon,lat. The geometries of sf are transformed to WGS84 if the CRS of the object is known. The following classes are supported:

sf with (MULTI)POLYGON geometries
sfc with (MULTI)POLYGON geometries
sfg with (MULTI)POLYGON geometries and WGS 84 coordinates
bbox created with sf::st_bbox() or tmaptools::bb()
matrix created with sp::bbox() or osmdata::getbb()
character providing textual definitions of bounding polygons, boxes or circles as allowed by the ohsome API (see ohsome API - Boundaries ):
- bboxes: WGS84 coordinates in the following format: "id1:lon1,lat1,lon2,lat2|id2:lon1,lat1,lon2,lat2|..." OR "lon1,lat1,lon2,lat2|lon1,lat1,lon2,lat2|..."
- bcircles: WGS84 coordinates + radius in meter in the following format: "id1:lon,lat,r|id2:lon,lat,r|..." OR "lon,lat,r|lon,lat,r|..."
- bpolys: WGS84 coordinates given as a list of coordinate pairs (as for bboxes) or GeoJSON FeatureCollection. The first point has to be the same as the last point and MultiPolygons are only supported in GeoJSON.
list of bbox, matrix or character. Bounding geometry types of all list elements must be the same. Does not work with GeoJSON FeatureCollections.

geometryType

character; type of geometry to be extracted:

"centroid",
"bboxes" (bounding boxes), or
"geometry"

Caveat: Node elements are omitted from results in queries for bounding boxes.

time

character; time parameter of the query (see Supported time formats).

properties

character; properties to be extracted with the features:

"tags", and/or
"metadata" (i.e. @changesetId, @lastEdit, @osmType, and @version)

Multiple values can be provided as comma-separated character or as character vector. This defaults to NULL (provides @osmId).

clipGeometry

logical; specifies whether the returned geometries should be clipped to the query’s spatial boundary

...

Parameters of the request to the ohsome API endpoint.

Details

ohsome_extract_elements() creates an ohsome_query object for OSM element extraction. ohsome_elements_bbox(), ohsome_elements_centroid() and ohsome_elements_geometry() are wrapper functions for specific elements extraction endpoints. Boundary objects are passed via set_boundary() into ohsome_boundary().

Examples

Run this code

# Extract geometries, metadata and tags of man-made objects around "Null Island":
ohsome_elements_geometry(
    "0,0,10", 
    filter = "man_made=*", 
    time = "2022-01-01",
    properties = c("metadata", "tags")
)