RbRouting

A ruby wrapper for some pgRouting 2.0 (http://pgrouting.org/) shortest-path functions

Preparing a pgRouting database

First make sure you have postgresql with postgis and pgRouting set up. You can use vagrant to get a pgRouting-ready database running quickly and easily:

$ git clone https://github.com/jordanderson/vagrant-postgis2
$ cd vagrant-postgis2
$ git submodule init
$ git submodule update
$ vagrant up
$ psql -h localhost -U postgres -p 6969 -W 

You'll be prompted for the postgres password. It's 'postgres'. The non-standard port is the default for the vagrant image defined above and is handy if you're already running a postgres server on localhost with port 5432.

Now, we'll create a postgres database called routing and add postgis and pgrouting extensions to it:

psql> CREATE DATABASE routing;
psql> \c routing
psql> CREATE EXTENSION postgis;
psql> CREATE EXTENSION pgrouting; 

Usage

To get started, the following should download OpenStreetMap (OSM) data for San Francisco, import it into your database using osm2pgrouting, and generate a shortest-path query using the turn-restricted shortest path (TRSP) algorithm provided by pgRouting.

$ brew install osm2pgrouting
$ curl http://osm-extracted-metros.s3.amazonaws.com/san-francisco.osm.bz2 | bunzip2 > /tmp/sf.osm
$ irb
irb> require 'rb_routing'
irb> trsp = RbRouting::Router::TrspByVertex.new :user => "postgres", :port => 6969, :password => "postgres", :database => "routing"
irb> trsp.import_osm_data "/tmp/sf.osm", "examples/mapconfig.xml"
irb> trsp.run :source => 550, :target => 5463
irb> trsp.path.to_json

Help and Docs

• http://rdoc.info/github/jordanderson/rb_routing/frames/file/README.md
• pgRouting 2.0 docs: http://docs.pgrouting.org/2.0/en/doc/index.html
• pgRouting source: https://github.com/pgRouting/pgrouting

To Do

• Edge-to-edge version of TRSP
• Create a result class to simplify output of various formats
• More tests
• Turn-by-turn directions
• Complex examples e.g. joins back to edge table, user preferences, turn restrictions
• More documentation