
Extract all osm_multipolygons from an osmdata_sf object
Source: R/osm-extract.R
osm_multipolygons.Rdid must be of an osm_points, osm_lines, or
osm_polygons object. osm_multipolygons returns any multipolygon
object(s) which contain the object specified by id.
See also
Other search:
osm_lines(),
osm_multilines(),
osm_points(),
osm_polygons()
Examples
# find all multipolygons which contain the single polygon called
# "Chiswick Eyot" (which is an island).
if (FALSE) { # \dontrun{
dat <- opq ("London UK") |>
add_osm_feature (key = "name", value = "Thames", exact = FALSE) |>
osmdata_sf ()
index <- which (dat$osm_multipolygons$name == "Chiswick Eyot")
id <- rownames (dat$osm_polygons [id, ])
osm_multipolygons (dat, id)
# That multipolygon is the Thames itself, but note that
nrow (dat$osm_multipolygons) # = 14 multipolygon objects
nrow (osm_multipolygons (dat, id)) # = 1 - the main Thames multipolygon
} # }