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Observed Stop Events from gps2gtfs Stop Times

Source: R/events.R
rt2s_events_from_stop_times.Rd

Converts the $stop_times table produced by gps2gtfs::g2g_extract_trips_and_stop_times() into observed stop events (see observed-stop-events).

Usage

rt2s_events_from_stop_times(
  stop_times,
  tz = "UTC",
  route_ref = NA_character_,
  source = c("positions", "gps"),
  trip_ref_prefix = "g2g_",
  trip_id_col = NULL,
  shape_ref_prefix = NULL
)

Arguments

stop_times

The gps2gtfs stop times table: columns trip_id, vehicle_id, direction (1/2), stop_id, and arrival_time/departure_time as absolute POSIXct values (gps2gtfs >= 0.2.0). Legacy "HH:MM:SS" strings are also accepted; they additionally require the date column they are interpreted within (and cannot represent a trip whose stop visits fall on the wrong side of midnight unambiguously - prefer POSIXct).

tz

Timezone the legacy "HH:MM:SS" strings refer to (the timezone the GPS data was cleaned in). Ignored for POSIXct input, which carries its own timezone. Default "UTC".

route_ref

Optional route identity to stamp on all events (gps2gtfs models one route per run). Default NA.

source

Provenance source label: "positions" (GTFS-RT Vehicle Positions, default) or "gps" (raw AVL/logger data).

trip_ref_prefix

Prefix for synthetic trip identities. When a trip has no official id (see trip_id_col), its trip ref is <prefix><yyyymmdd>_<trip_id> so synthetic refs stay unique across service dates. Default "g2g_".

trip_id_col

Optional name of a column carrying the official trip identity (e.g. "provided_trip_id", as emitted by gps2gtfs's fast path from a GTFS-Realtime trip_id). Where present and non-missing, its value becomes the trip_ref verbatim, so baseline-mode assembly can match observed trips to the baseline trips.txt; trips lacking it fall back to a synthetic ref. NULL (default) auto-detects a provided_trip_id column and uses it when present.

shape_ref_prefix

Optional character prefix for populating shape_ref from the internal trip_id, as <prefix><trip_id>. Set it to the shape_id_prefix used with gps2gtfs::g2g_shapes_from_trips() (default there "SHP_") so the assembler can link trips.shape_id to those shapes. NULL (default) leaves shape_ref as NA (no shape linkage).

Value

A validated observed stop events data.table.

Details

Each trip is attributed to one service day: the day (in the times' timezone) of its first observed stop. Post-midnight stops keep their trip's service date, so an overnight trip yields a single trip_ref and the assembler renders its late stops as >24:00:00 clock times.