Construct a travel time matrix between all pairs of stops in a 'GTFS' feed.

Usage

m4ra_gtfs_traveltimes(
  gtfs,
  start_time_limits,
  day,
  from_stops = NULL,
  next_interval = TRUE,
  quiet = FALSE
)

gtfs: A 'GTFS' feed extracted with the gtfsrouter function, 'extract_gtfs'.
start_time_limits: As for the 'gtfs_traveltimes' function of gtfsrouter, a vector of two values specifying the earliest and latest departure times from each station.
day: As for the 'gtfs_traveltimes' function of gtfsrouter, the day for which the matrix is to be calculated.
from_stops: If not NULL (default), calculate travel times only from the stops identified in this parameter. All values must be stops taken from gtfs$stops$stop_id.
next_interval: If TRUE, calculate time intervals to subsequent trips after identified fastest trips. These subsequent trips may not necessarily be as fast as the initial trips, and so this requires a second calculation of all travel times. Setting this parameter to TRUE will therefore generally double the calculation time. Note that intervals to subsequent trips may be negative where alternative connections with greater numbers of transfers leave earlier than initial, minimal-transfer trips.
quiet: If FALSE, display progress information on screen.

A list of two or three integer matrices:

"duration": The fastest travel times between all pairs of stops for the specified 'start_time_limits'; and
"ntransfers": The corresponding numbers of transfers.
(Only if 'next_interval = TRUE') "intervals": a matrix of intervals (in seconds) until the next fastest service after that corresponding to the times in the 'duration' item.