gtfs_route: gtfs_route

In gtfsrouter: Routing with 'GTFS' (General Transit Feed Specification) Data

gtfs_route

Description

Calculate single route between a start and end station departing at or after a specified time.

Usage

gtfs_route(
  gtfs,
  from,
  to,
  start_time = NULL,
  day = NULL,
  route_pattern = NULL,
  earliest_arrival = TRUE,
  include_ids = FALSE,
  grep_fixed = TRUE,
  max_transfers = NA,
  from_to_are_ids = FALSE,
  quiet = FALSE
)

Arguments

gtfs	A set of GTFS data returned from extract_gtfs or, for more efficient queries, pre-processed with gtfs_timetable.
from	Names, IDs, or approximate (lon, lat) coordinates of start stations (as stop_name or stop_id entry in the stops table, or a vector of two numeric values). See Note.
to	Corresponding Names, IDs, or coordinates of end station.
start_time	Desired departure time at from station, either in seconds after midnight, a vector of two or three integers (hours, minutes) or (hours, minutes, seconds), an object of class difftime, hms, or lubridate. If not provided, current time is used.
day	Day of the week on which to calculate route, either as an unambiguous string (so "tu" and "th" for Tuesday and Thursday), or a number between 1 = Sunday and 7 = Saturday. If not given, the current day will be used. (Not used if gtfs has already been prepared with gtfs_timetable.)
route_pattern	Using only those routes matching given pattern, for example, "^U" for routes starting with "U" (as commonly used for underground or subway routes. To negate the route_pattern – that is, to include all routes except those matching the pattern – prepend the value with "!"; for example "!^U" will include all services except those starting with "U". (This parameter is not used at all if gtfs has already been prepared with gtfs_timetable.)
earliest_arrival	If FALSE, routing will be with the first-departing service, which may not provide the earliest arrival at the to station. This may nevertheless be useful for bulk queries, as earliest arrival searches require two routing queries, while earliest departure searches require just one, and so will be generally twice as fast.
include_ids	If TRUE, result will include columns containing GTFS-specific identifiers for routes, trips, and stops.
grep_fixed	If FALSE, match station names (when passed as character string) with grep(..., fixed = FALSE), to allow use of grep expressions. This is useful to refine matches in cases where desired stations may match multiple entries.
max_transfers	If not NA, specify a desired maximum number of transfers for the route (including but not exceeding this number). This parameter may be used to generate alternative routes with fewer transfers, although actual numbers of transfers may still exceed this number if the value specified is less than the minimal feasible number of transfers.
from_to_are_ids	Set to TRUE to enable from and to parameter to specify entries in stop_id rather than stop_name column of the stops table.
quiet	Set to TRUE to suppress screen messages (currently just regarding timetable construction).

Value

For single (from, to) values, a data.frame describing the route, with each row representing one stop. For multiple (from, to) values, a list of data.frames, each of which describes one route between the i'th start and end stations (from and to values). Origin and destination stations for which no route is possible return NULL.

Note

This function will by default calculate the route that arrives earliest at the specified destination, although this may depart later than the earliest departing service. Routes which depart at the earliest possible time can be calculated by setting earliest_arrival = FALSE.

See Also

Other main: gtfs_route_headway(), gtfs_traveltimes()

Examples

# Examples must be run on single thread only:
nthr_dt <- data.table::setDTthreads (1)
nthr_omp <- Sys.getenv ("OMP_THREAD_LIMIT")
Sys.setenv ("OMP_THREAD_LIMIT" = 1L)

berlin_gtfs_to_zip () # Write sample feed from Berlin, Germany to tempdir
f <- file.path (tempdir (), "vbb.zip") # name of feed
gtfs <- extract_gtfs (f)
from <- "Innsbrucker Platz" # U-bahn station, not "S"
to <- "Alexanderplatz"
start_time <- 12 * 3600 + 120 # 12:02

route <- gtfs_route (gtfs, from = from, to = to, start_time = start_time)

# Specify day of week
route <- gtfs_route (
    gtfs,
    from = from,
    to = to,
    start_time = start_time,
    day = "Sunday"
)

# specify travel by "U" = underground only
route <- gtfs_route (
    gtfs,
    from = from,
    to = to,
    start_time = start_time,
    day = "Sunday",
    route_pattern = "^U"
)
# specify travel by "S" = street-level only (not underground)
route <- gtfs_route (
    gtfs,
    from = from,
    to = to,
    start_time = start_time,
    day = "Sunday",
    route_pattern = "^S"
)

# Route queries are generally faster if the GTFS data are pre-processed with
# `gtfs_timetable()`:
gt <- gtfs_timetable (gtfs, day = "Sunday", route_pattern = "^S")
route <- gtfs_route (gt, from = from, to = to, start_time = start_time)

data.table::setDTthreads (nthr_dt)
Sys.setenv ("OMP_THREAD_LIMIT" = nthr_omp)

gtfsrouter documentation built on Oct. 29, 2024, 9:06 a.m.