filter_by_spatial_extent: Filter a GTFS object using a spatial extent

In gtfstools: General Transit Feed Specification (GTFS) Editing and Analysing Tools

Filter a GTFS object using a spatial extent

Description

Filters 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.

Usage

filter_by_spatial_extent(
  gtfs,
  geom,
  spatial_operation = sf::st_intersects,
  keep = TRUE
)

Arguments

gtfs	A GTFS object, as created by read_gtfs().
geom	An sf, sfc or bbox object, in WGS 84 (EPSG 4326). Describes the spatial extent used to filter the data. A bbox is treated as a rectangle in longitude and latitude (unlike sf::st_as_sfc(bbox), whose edges are geodesics when {s2} is used).
spatial_operation	A spatial operation function from the set of options listed in geos_binary_pred. 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. sf::st_equals_exact() and sf::st_is_within_distance() are not supported, since they require additional arguments.
keep	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).

Value

The GTFS object passed to the gtfs parameter, after the filtering process.

See Also

Other filtering functions: filter_by_agency_id(), filter_by_date(), filter_by_period(), filter_by_route_id(), filter_by_route_type(), filter_by_service_id(), filter_by_shape_id(), filter_by_stop_id(), filter_by_time_of_day(), filter_by_trip_id(), filter_by_weekday()

Examples

data_path <- system.file("extdata/spo_gtfs.zip", package = "gtfstools")
gtfs <- read_gtfs(data_path)

shape_id <- "68962"
shape_sf <- get_shapes_geometry(gtfs, shape_id)
bbox <- sf::st_bbox(shape_sf)
object.size(gtfs)

# keeps entries that intersect with the specified polygon
smaller_gtfs <- filter_by_spatial_extent(gtfs, bbox)
object.size(smaller_gtfs)

# drops entries that intersect with the specified polygon
smaller_gtfs <- filter_by_spatial_extent(gtfs, bbox, keep = FALSE)
object.size(smaller_gtfs)

# 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)

gtfstools documentation built on Oct. 28, 2026, 5:13 p.m.