go_home: go_home

Description

Use local environmental variables specifying home and work stations and locations of locally-stored GTFS data to route from work to home location with next available service.

Usage

go_home(wait = 0, start_time)

Value

A data.frame specifying the next available route from work to home.

Arguments

wait: An integer specifying the n-th next service. That is, wait = n will return the n-th available service after the next immediate service.
start_time: If given, search for connections after specified time; if not given, search for connections from current time.

Details

This function, and the complementary function go_to_work, requires three local environmental variables specifying the names of home and work stations, and the location on local storage of the GTFS data set to be used for routing. These are respectively called gtfs_home, gtfs_work, and gtfs_data. This data set must also be pre-processed using the process_gtfs_local function.

See Startup for details on how to set environmental variables. Briefly, this can be done in two main ways: By setting them at the start of each session, in which case the variables may be set with: Sys.setenv ("gtfs_home" = "<my home station>") Sys.setenv ("gtfs_work" = "<my work station>") Sys.setenv ("gtfs_data" = "/full/path/to/gtfs.zip") Alternatively, to set these automatically for each session, paste those lines into the file ~/.Renviron - that is, a file named ".Renviron" in the user's home directory.

The process_gtfs_local function reduces the GTFS data set to the minimal possible size necessary for local routing. GTFS data are nevertheless typically quite large, and both the go_home and go_to_work functions may take some time to execute. Most of this time is devoted to loading the data in to the current workspace and as such is largely unavoidable.

Examples

Run this code

if (FALSE) {
# For general use, please set these three variables:
Sys.setenv ("gtfs_home" = "")
Sys.setenv ("gtfs_work" = "")
Sys.setenv ("gtfs_data" = "/full/path/to/gtfs.zip")

# The following illustrate use with sample data bundled with package
Sys.setenv ("gtfs_home" = "Tempelhof")
Sys.setenv ("gtfs_work" = "Alexanderplatz")
Sys.setenv ("gtfs_data" = file.path (tempdir (), "vbb.zip"))
process_gtfs_local () # If not already done
go_home (start_time = "12:00") # next available service after 12:00
go_home (3, start_time = "12:00") # Wait until third service after that

# Generally, `start_time` will not be specified, in which case `go_home` will
# return next available service from current system time, so calls will
# generally be as simple as:
go_home ()
go_home (3)
}