add_osm_feature: Add a feature to an Overpass query

In osmdata: Import 'OpenStreetMap' Data as Simple Features or Spatial Objects

Add a feature to an Overpass query

Description

Add a feature to an Overpass query

Usage

add_osm_feature(
  opq,
  key,
  value,
  key_exact = TRUE,
  value_exact = TRUE,
  match_case = TRUE,
  bbox = NULL
)

Arguments

opq	An overpass_query object
key	feature key
value	value for feature key; can be negated with an initial exclamation mark, value = "!this", and can also be a vector, value = c ("this", "that").
key_exact	If FALSE, key is not interpreted exactly; see https://wiki.openstreetmap.org/wiki/Overpass_API
value_exact	If FALSE, value is not interpreted exactly
match_case	If FALSE, matching for both key and value is not sensitive to case
bbox	optional bounding box for the feature query; must be set if no opq query bbox has been set

Value

opq object

add_osm_feature vs add_osm_features

Features defined within an add_osm_features call are combined with a logical OR.

Chained calls to either add_osm_feature or add_osm_features() combines features from these calls in a logical AND; this is analagous to chaining dplyr::filter() on a data frame.

add_osm_features() with only one feature is logically equivalent to add_osm_feature().

Note

key_exact should generally be TRUE, because OSM uses a reasonably well defined set of possible keys, as returned by available_features. Setting key_exact = FALSE allows matching of regular expressions on OSM keys, as described in Section 6.1.5 of https://wiki.openstreetmap.org/wiki/Overpass_API/Overpass_QL. The actual query submitted to the overpass API can be obtained from opq_string.

References

https://wiki.openstreetmap.org/wiki/Map_Features

See Also

add_osm_features

Other queries: add_osm_features(), bbox_to_string(), getbb(), opq_around(), opq_enclosing(), opq_osm_id(), opq_string(), opq(), overpass_status()

Examples

## Not run: 
q <- opq ("portsmouth usa") %>%
    add_osm_feature (
        key = "amenity",
        value = "restaurant"
    ) %>%
    add_osm_feature (key = "amenity", value = "pub")
osmdata_sf (q) # all objects that are restaurants AND pubs (there are none!)
q1 <- opq ("portsmouth usa") %>%
    add_osm_feature (
        key = "amenity",
        value = "restaurant"
    )
q2 <- opq ("portsmouth usa") %>%
    add_osm_feature (key = "amenity", value = "pub")
c (osmdata_sf (q1), osmdata_sf (q2)) # all restaurants OR pubs
# Use of negation to extract all non-primary highways
q <- opq ("portsmouth uk") %>%
    add_osm_feature (key = "highway", value = "!primary")

## End(Not run)

osmdata documentation built on June 9, 2022, 5:09 p.m.