opq: Build an Overpass query

Description

Build an Overpass query

Usage

opq(
  bbox = NULL,
  nodes_only = FALSE,
  osm_types = c("node", "way", "relation"),
  out = c("body", "tags", "meta", "skel", "tags center", "ids"),
  datetime = NULL,
  datetime2 = NULL,
  adiff = FALSE,
  timeout = 25,
  memsize
)

Value

An overpass_query object

Arguments

bbox: Either (i) four numeric values specifying the maximal and minimal longitudes and latitudes, in the form c(xmin, ymin, xmax, ymax) or (ii) a character string in the form xmin,ymin,xmax,ymax. These will be passed to getbb to be converted to a numerical bounding box. Can also be (iii) a matrix representing a bounding polygon as returned from getbb(..., format_out = "polygon"). To search in an area, (iv) a character string with a relation or a (closed) way id in the format "way(id:1)", "relation(id:1, 2)" or "relation(id:1, 2, 3); way(id:2)" as returned by getbb(..., format_out = "osm_type_id") or bbox_to_string with a data.frame from getbb(..., format_out = "data.frame") to select all areas combined (relations and ways).
nodes_only: WARNING: this parameter is equivalent to osm_types = "node" and will be DEPRECATED. If TRUE, query OSM nodes only. Some OSM structures such as place = "city" or highway = "traffic_signals" are represented by nodes only. Queries are built by default to return all nodes, ways, and relation, but this can be very inefficient for node-only queries. Setting this value to TRUE for such cases makes queries more efficient, with data returned in the osm_points list item.
osm_types: A character vector with several OSM types to query: node, way and relation is the default. nwr, nw, wr, nr and rel are also valid types. Ignored if nodes_only = TRUE. osm_types = "node" is equivalent to nodes_only = TRUE.
out: The level of verbosity of the overpass result: body (geometries and tags, the default), tags (tags without geometry), meta (like body + Timestamp, Version, Changeset, User, User ID of the last edition), skel (geometries only), tags center (tags without geometry + the coordinates of the center of the bounding box) and ids (type and id of the objects only).
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 datetime and datetime2, where datetime2 > datetime. See https://wiki.openstreetmap.org/wiki/Overpass_API/Overpass_QL#Difference_between_two_dates_(diff).
adiff: If TRUE, query for augmented difference. The result indicates what happened to the modified and deleted OSM objects. Requires datetime(2)*.
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.

Details

The out statement for tags, tags centerand id, do not return geometries. Neither out = "meta" nor adiff = TRUE options are implemented for all osmdata_* functions yet. Use osmdata_xml or osmdata_data_frame to get the result of these queries. See the documentation of the out statement and augmented difference for more details about these options.

Examples

Run this code

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)

# Filter by a search area
qa1 <- getbb ("Catalan Countries", format_out = "osm_type_id") %>%
    opq (nodes_only = TRUE) %>%
    add_osm_feature (key = "capital", value = "4")
opqa1 <- osmdata_sf (qa1)
# Filter by a multiple search areas
bb <- getbb ("Vilafranca", format_out = "data.frame")
qa2 <- bbox_to_string (bb [bb$osm_type != "node", ]) %>%
    opq (nodes_only = TRUE) %>%
    add_osm_feature (key = "place")
opqa2 <- osmdata_sf (qa2)
}

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