podigg v1.0.7

PoDiGG

POpulation DIstribution-based Gtfs Generator

A realistic public transport dataset generator, which is serialized as GTFS.

It is based on five sub-generators:

• Region: A geographical area of cells where each cells contains a population value.
• Stops: Tagging of cells with stop or no stop.
• Edges: Adding transport edges between stops.
• Routes: Routes over one or more edges.
• Connections: Instantiation of routes at times.

Install

This generator is a Node.js application that can be installed by running:

[sudo] npm install -g podigg

Usage

Command line

The easiest way to run the generator is using the command line tool:

podigg [output folder [path to a JSON config file]]

The default output folder is output_data.

This config file contains parameters for the generator, as explained below. Example of a config file:

{
    "seed": 1,
    "stops:stops": 100,
    "connections:connections": 3000
}

Alternatively, the generator can also be configured using environment variables, as explained below. In that case, the generator must be called as follows:

podigg-env [output folder]

From code

The generator can be included into your application as follows:

const PodiggGenerator = require('podigg');
new PodiggGenerator({
    "seed": 1,
    "stops:stops": 100,
    "connections:connections": 3000
}).generate('output_data');

Docker

Downloading and running the container from the Docker hub:

docker pull podigg/podigg
docker run --rm -it -v $(pwd)/docker-out:/output_data -e GTFS_GEN_SEED=100 podigg/podigg

Building and running the container from this repo:

git clone git@github.com:PoDiGG/podigg.git
cd podigg
docker build -t podigg .
docker run --rm -it -v $(pwd)/docker-out:/output_data -e GTFS_GEN_SEED=100 podigg

Parameters must be passed using environment variables.

Parameters

All parameters are scoped by their generator name in lower-case, except for the general parameters. For example, choosing a region's latitude offset is done with the parameter region:lat_offset.

When configuring parameters via environment variables, parameters should be defined with the prefix GTFS_GEN_, followed by the generator name + __ (or empty if general) and the parameter name. The generator and parameter names can either be upper or lower case. For example, choosing a region's latitude offset is done with the parameter GTFS_GEN_REGION__LAT_OFFSET, and choosing the seed is done with GTFS_GEN_SEED.

General

Region

Several region generators exist which are explained hereafter, one of them needs to be selected.

Config prefix: region:

File

Noisy

A noise-based generator, where population values are influenced by nearby cells.

Isolated

A generator that creates a given number of circular clusters of population. The population density is high at the center of the cluster and decreases to zero when going to the border of the cluster.

Stops

The generation of stops

Config prefix: stops:

Edges

The generation of edges

Config prefix: edges:

Routes

The generation of trips and routes

Config prefix: routes:

Connections

The generation of connections

Config prefix: connections:

Query Set

Optionally, PoDiGG can also generate realistic route planning query sets based on the generated dataset. For this, the queryset:generate option must be set to true.

Config prefix: queryset:

License

The PoDiGG generator is written by Ruben Taelman.

This code is copyrighted by Ghent University – imec and released under the MIT license.