Package 'gps2gtfs'

Clean Raw GPS Data

Description

Cleans raw GPS data by removing records with latitude or longitude equal to zero, parsing the device time, and sorting by device ID, date, and time.

Usage

g2g_clean_gps(raw_gps_df, projected = NULL)

Arguments

raw_gps_df	A data.frame containing raw GPS data. Must include columns: id, deviceid, latitude, longitude, devicetime, and speed.
projected	Logical. Is the coordinates data already projected? Default is NULL (auto-detect).

Value

A sorted data.table with additional date and time_str columns.

Examples

data(g2g_data_gps)
cleaned_gps <- g2g_clean_gps(g2g_data_gps)
head(cleaned_gps)

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GPS Trajectory Subset

Description

A lightweight subset of raw bus GPS data from Kandy, Sri Lanka. This dataset is intended for examples and testing of the gps2gtfs pipeline.

Usage

g2g_data_gps

Format

A data frame with 1045 rows and 6 variables:

id

Unique identifier for the GPS record.

deviceid

Unique identifier for the tracking device (bus).

devicetime

Timestamp of the GPS ping (UTC).

latitude

Latitude in WGS-84 degrees.

longitude

Longitude in WGS-84 degrees.

speed

Recorded speed of the vehicle.

Source

Original data from the Python gps2gtfs package.

References

Ratneswaran, S., & Thayasivam, U. (2023). Extracting potential Travel time information from raw GPS data and Evaluating the Performance of Public transit - a case study in Kandy, Sri Lanka. 2023 3rd International Conference on Intelligent Communication and Computational Techniques (ICCT), 1-7. doi:10.1109/ICCT56969.2023.10075789

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Bus Stops Data

Description

Sample data containing the coordinates and metadata for bus stops. This dataset works together with g2g_data_gps to extract stop times.

Usage

g2g_data_stops

Format

A data frame with 23 rows and 6 variables:

stop_id

Unique identifier for the bus stop.

route_id

Route identifier the stop belongs to.

direction

Direction of the route the stop serves.

latitude

Latitude in WGS-84 degrees.

longitude

Longitude in WGS-84 degrees.

address

Address or name of the stop location.

Source

Original data from the Python gps2gtfs package.

References

Ratneswaran, S., & Thayasivam, U. (2023). Extracting potential Travel time information from raw GPS data and Evaluating the Performance of Public transit - a case study in Kandy, Sri Lanka. 2023 3rd International Conference on Intelligent Communication and Computational Techniques (ICCT), 1-7. doi:10.1109/ICCT56969.2023.10075789

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Bus Terminals Data

Description

Sample data containing the coordinates for bus route terminals. Used to define the start and end of trips.

Usage

g2g_data_terminals

Format

A data frame with 2 rows and 4 variables:

terminal_id

Unique identifier for the bus terminal.

terminal_name

Name of the terminal.

latitude

Latitude in WGS-84 degrees.

longitude

Longitude in WGS-84 degrees.

Source

Original data from the Python gps2gtfs package.

References

Ratneswaran, S., & Thayasivam, U. (2023). Extracting potential Travel time information from raw GPS data and Evaluating the Performance of Public transit - a case study in Kandy, Sri Lanka. 2023 3rd International Conference on Intelligent Communication and Computational Techniques (ICCT), 1-7. doi:10.1109/ICCT56969.2023.10075789

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Extract Trips from GPS Trajectories

Description

Reads raw GPS and terminal CSV files, extracts trips, and optionally writes results to a CSV.

Usage

g2g_extract_trips(
  gps_data,
  terminals_data,
  terminals_buffer_radius,
  output_path = NULL,
  projected_crs = NULL,
  backend = "auto",
  projected = NULL
)

Arguments

gps_data	A data.frame or path to the raw GPS CSV.
terminals_data	A data.frame or path to the terminal coordinates CSV.
terminals_buffer_radius	Numeric. Buffer radius for terminals (in meters).
output_path	Character. Optional path to write output trip features as CSV. Default is NULL (no file written).
projected_crs	Numeric. The EPSG code of a projected coordinate system used for metric distance calculations. Required when projected = TRUE; otherwise a suitable UTM projection is selected when omitted.
backend	Character. The backend to use: "auto", "rust", "rcpp", or "pure_r". Automatic selection prefers Rust, then Rcpp, then pure R. Explicit unavailable backends produce an error.
projected	Logical. Whether plain-table coordinates are already projected. Out-of-bounds coordinates require explicit TRUE.

Value

A data.table containing extracted trip features.

Examples

data(g2g_data_gps)
data(g2g_data_terminals)
trips <- g2g_extract_trips(
  gps_data = g2g_data_gps,
  terminals_data = g2g_data_terminals,
  terminals_buffer_radius = 50
)

---

Extract Trips and Stop Times from GPS Trajectories

Description

Reads raw GPS, terminal, and stop CSV files, extracts trips and stop times, and optionally writes results.

Usage

g2g_extract_trips_and_stop_times(
  gps_data,
  terminals_data,
  stops_data,
  terminals_buffer_radius,
  stops_buffer_radius,
  stops_extended_buffer_radius,
  output_trips_path = NULL,
  output_stops_path = NULL,
  projected_crs = NULL,
  backend = "auto",
  projected = NULL,
  stop_direction_map = NULL
)

Arguments

gps_data	A data.frame or path to the raw GPS CSV.
terminals_data	A data.frame or path to the terminal coordinates CSV.
stops_data	A data.frame or path to the bus stops coordinates CSV.
terminals_buffer_radius	Numeric. Buffer radius for terminals (in meters).
stops_buffer_radius	Numeric. Buffer radius for bus stops (in meters).
stops_extended_buffer_radius	Numeric. Extended buffer radius for bus stops (in meters).
output_trips_path	Character. Optional path to write output trip features as CSV. Default is NULL (no file written).
output_stops_path	Character. Optional path to write output stop times as CSV. Default is NULL (no file written).
projected_crs	Numeric. The EPSG code of a projected coordinate system used for metric distance calculations. Required when projected = TRUE; otherwise a suitable UTM projection is selected when omitted.
backend	Character. The backend to use: "auto", "rust", "rcpp", or "pure_r". Automatic selection prefers Rust, then Rcpp, then pure R. Explicit unavailable backends produce an error.
projected	Logical. Whether plain-table coordinates are already projected. Out-of-bounds coordinates require explicit TRUE.
stop_direction_map	Optional named character vector mapping each raw stop-direction label to its starting terminal ID.

Value

A list containing two data.tables: trips and stop_times (with columns matching GTFS standard naming).

Examples

data(g2g_data_gps)
data(g2g_data_terminals)
data(g2g_data_stops)
result <- g2g_extract_trips_and_stop_times(
  gps_data = g2g_data_gps,
  terminals_data = g2g_data_terminals,
  stops_data = g2g_data_stops,
  terminals_buffer_radius = 50,
  stops_buffer_radius = 30,
  stops_extended_buffer_radius = 50
)
head(result$trips)
head(result$stop_times)

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