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Trim an osmdata object to within a bounding polygon


trim_osmdata(dat, bb_poly, exclude = TRUE)



An osmdata object returned from osmdata_sf or osmdata_sp.


A matrix representing a bounding polygon obtained with getbb (..., format_out = "polygon") (and possibly selected from resultant list where multiple polygons are returned).


If TRUE, objects are trimmed exclusively, only retaining those strictly within the bounding polygon; otherwise all objects which partly extend within the bounding polygon are retained.


A trimmed version of dat, reduced only to those components lying within the bounding polygon.


It will generally be necessary to pre-load the sf package for this function to work correctly.

Caution is advised when using polygons obtained from Nominatim via getbb(..., format_out = "polygon"|"sf_polygon"). These shapes can be outdated and thus could cause the trimming operation to not give results expected based on the current state of the OSM data.

See also


if (FALSE) {
dat <- opq ("colchester uk") %>%
    add_osm_feature (key = "highway") %>%
    osmdata_sf (quiet = FALSE)
bb <- getbb ("colchester uk", format_out = "polygon")
library (sf) # required for this function to work
dat_tr <- trim_osmdata (dat, bb)
bb <- getbb ("colchester uk", format_out = "sf_polygon")
class (bb) # sf data.frame
dat_tr <- trim_osmdata (dat, bb)
bb <- as (bb, "Spatial")
class (bb) # SpatialPolygonsDataFrame
dat_tr <- trim_osmdata (dat, bb)