Build an Overpass query
opq( bbox = NULL, nodes_only = FALSE, datetime = NULL, datetime2 = NULL, timeout = 25, memsize )
bbox | Either (i) four numeric values specifying the maximal and minimal
longitudes and latitudes, in the form |
---|---|
nodes_only | If |
datetime | If specified, a date and time to extract data from the OSM database as it was up to the specified date and time, as described at https://wiki.openstreetmap.org/wiki/Overpass_API/Overpass_QL#date. This must be in ISO8601 format ("YYYY-MM-DDThh:mm:ssZ"), where both the "T" and "Z" characters must be present. |
datetime2 | If specified, return the difference in the OSM
database between |
timeout | It may be necessary to increase this value for large queries, because the server may time out before all data are delivered. |
memsize | The default memory size for the 'overpass' server in bytes; may need to be increased in order to handle large queries. |
An overpass_query
object
See
https://wiki.openstreetmap.org/wiki/Overpass_API#Resource_management_options_.28osm-script.29
for explanation of timeout
and memsize
(or maxsize
in overpass terms).
Note in particular the comment that queries with arbitrarily large memsize
are likely to be rejected.
if (FALSE) { q <- getbb ("portsmouth", display_name_contains = "United States") %>% opq () %>% add_osm_feature("amenity", "restaurant") %>% add_osm_feature("amenity", "pub") osmdata_sf (q) # all objects that are restaurants AND pubs (there are none!) q1 <- getbb ("portsmouth", display_name_contains = "United States") %>% opq () %>% add_osm_feature("amenity", "restaurant") q2 <- getbb ("portsmouth", display_name_contains = "United States") %>% opq () %>% add_osm_feature("amenity", "pub") c (osmdata_sf (q1), osmdata_sf (q2)) # all restaurants OR pubs # Use nodes_only to retrieve single point data only, such as for central # locations of cities. opq <- opq (bbox, nodes_only = TRUE) %>% add_osm_feature (key = "place", value = "city") %>% osmdata_sf (quiet = FALSE) }