R/filter_by_spatial_extent.R
filter_by_spatial_extent.RdFilters a GTFS object using a spatial extent (passed as an sf object),
keeping (or dropping) entries related to shapes and trips whose geometries
are selected through a specified spatial operation.
filter_by_spatial_extent(
gtfs,
geom,
spatial_operation = sf::st_intersects,
keep = TRUE
)A GTFS object, as created by read_gtfs().
An sf object. Describes the spatial extent used to filter the
data.
A spatial operation function from the set of
options listed in geos_binary_pred (check the
DE-I9M Wikipedia entry for the
definition of each function). Defaults to sf::st_intersects, which
tests if the shapes and trips have ANY intersection with the object
specified in geom. Please note that geom is passed as the x argument
of these functions.
A logical. Whether the entries related to the shapes and trips
selected by the given spatial operation should be kept or dropped (defaults
to TRUE, which keeps the entries).
The GTFS object passed to the gtfs parameter, after the filtering
process.
Other filtering functions:
filter_by_agency_id(),
filter_by_route_id(),
filter_by_route_type(),
filter_by_service_id(),
filter_by_sf(),
filter_by_shape_id(),
filter_by_stop_id(),
filter_by_time_of_day(),
filter_by_trip_id(),
filter_by_weekday()
data_path <- system.file("extdata/spo_gtfs.zip", package = "gtfstools")
gtfs <- read_gtfs(data_path)
shape_id <- "68962"
shape_sf <- convert_shapes_to_sf(gtfs, shape_id)
bbox <- sf::st_bbox(shape_sf)
object.size(gtfs)
#> 860808 bytes
# keeps entries that intersect with the specified polygon
smaller_gtfs <- filter_by_spatial_extent(gtfs, bbox)
object.size(smaller_gtfs)
#> 324952 bytes
# drops entries that intersect with the specified polygon
smaller_gtfs <- filter_by_spatial_extent(gtfs, bbox, keep = FALSE)
object.size(smaller_gtfs)
#> 512288 bytes
# uses a different function to filter the gtfs
smaller_gtfs <- filter_by_spatial_extent(
gtfs,
bbox,
spatial_operation = sf::st_contains
)
object.size(smaller_gtfs)
#> 68976 bytes