R: Extract all 'osm_multipolygons' from an osmdata object

osm_multipolygons {osmdata}

R Documentation

Extract all `osm_multipolygons` from an osmdata object

Description

id 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.

Usage

osm_multipolygons(dat, id)

Arguments

`dat`	An object of class osmdata
`id`	OSM identification of one or more objects for which multipolygons are to be extracted

Value

An sf Simple Features Collection of multipolygons

Examples

## Not run: 
# find all multipolygons which contain the single polygon called
# "Chiswick Eyot" (which is an island).
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

## End(Not run)