filter_functions: Filter GTFS Data by Service, Route, Date, Stop, Trip, and...

In GTFSwizard: Exploring and Manipulating 'GTFS' Files

Filter GTFS Data by Service, Route, Date, Stop, Trip, and Time

Description

The 'filter_' functions selectively filter data within a 'wizardgtfs' object based on criteria such as service patterns, specific dates, service IDs, route IDs, trip IDs, stop IDs, or time ranges.

Usage

filter_servicepattern(gtfs, servicepattern = NULL)

filter_date(gtfs, dates = NULL)

filter_service(gtfs, service)

filter_route(gtfs, route, keep = TRUE)

filter_trip(gtfs, trip, keep = TRUE)

filter_stop(gtfs, stop)

filter_time(gtfs, from = "0:0:0", to = "48:00:00")

Arguments

gtfs	A GTFS object, preferably of class 'wizardgtfs'. If not, the function will attempt to convert it using 'GTFSwizard::as_wizardgtfs()'.
servicepattern	(Optional) A character vector of service patterns to retain. Defaults to the most frequent pattern (typical day) if 'NULL'.
dates	(Optional) A date or vector of dates (as "YYYY-MM-DD" character or POSIXct) to filter services active on those dates. Return the furtherst available date if 'NULL'.
service	(Optional) A character vector of service IDs to retain in the 'wizardgtfs' object.
route	(Optional) A character vector of route IDs to retain in the 'wizardgtfs' object. When 'keep = FALSE', excludes the specified routes.
keep	Logical. When 'TRUE' (default), retains specified 'route' or 'trip' IDs; when 'FALSE', excludes them.
trip	(Optional) A character vector of trip IDs to retain in the 'wizardgtfs' object. When 'keep = FALSE', excludes the specified trips.
stop	(Optional) A character vector of stop IDs to retain.
from	(Optional) Start time in "HH:MM:SS" format to include only trips that start after this time. Defaults to '0:0:0'.
to	(Optional) End time in "HH:MM:SS" format to include only trips that end before this time. Defaults to '48:00:00'.

Details

Each 'filter_' function targets a specific aspect of the GTFS data, applying filters to the relevant tables:

- filter_servicepattern: Filters by specified service patterns in the GTFS data. If no pattern is provided, defaults to the most frequent one.

- filter_date: Filters data by a date or dates, returning only services active on those dates.

- filter_service: Filters by service ID, retaining data related to specified services.

- filter_route: Filters by route ID. When 'keep = TRUE', only specified routes are retained; when 'FALSE', the specified routes are excluded.

- filter_trip: Filters by trip ID, using 'keep' to either retain or exclude specified trips.

- filter_stop: Filters by stop ID, retaining only stops and related data (trips, routes, etc.) associated with the specified stops.

- filter_time: Filters stop times within a specified time range (between 'from' and 'to').

These functions selectively subset the GTFS tables ('trips', 'stop_times', 'routes', 'agency', 'shapes', etc.), maintaining only the records that meet the defined criteria. If a table or required column is missing from the GTFS data, the function will either attempt to infer it using available data or exclude the table as necessary.

Value

A filtered 'wizardgtfs' object containing only the records that match the specified criteria.

See Also

[GTFSwizard::as_wizardgtfs()], [GTFSwizard::get_servicepattern()]

Examples

# Filter by service pattern
filtered_gtfs <- filter_servicepattern(gtfs = for_rail_gtfs, servicepattern = "servicepattern-1")

# Filter by a specific date
filtered_gtfs <- filter_date(gtfs = for_rail_gtfs, dates = "2021-02-10")

# Filter by route ID, keeping only specified routes
filtered_gtfs <- filter_route(gtfs = for_rail_gtfs, route = for_rail_gtfs$routes$route_id[1:2])

# Filter by trip ID, excluding specified trips
filtered_gtfs <- filter_trip(gtfs = for_rail_gtfs,
                              trip = for_rail_gtfs$trips$trip_id[1:2],
                              keep = FALSE)

# Filter by a time range
filtered_gtfs <- filter_time(gtfs = for_rail_gtfs, from = "06:30:00", to = "10:00:00")

GTFSwizard documentation built on April 4, 2025, 4:10 a.m.