Netica

The Netica gem provides tools for interacting with Bayesian networks using JRuby and the Netica-J API, published by Norsys Software Corp..

Installation

Download the Netica-J API from Norsys and place the NeticaJ.jar file in your JRuby load path. Possible locations include...

/Library/Java/Extensions
/Network/Library/Java/Extensions
/System/Library/Java/Extensions
/usr/lib/java

Add this line to your application's Gemfile:

gem 'netica'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install netica

Usage

Here's an example, based the Probabilistic Inference example in the Netica-J Manual.

Use Netica::Environment.engage to create a Netica Environ singleton object:

processor = Netica::Environment.engage
=> true

Create an ActiveNetwork, using a .dne file created in the Netica Application.

my_network = Netica::ActiveNetwork.new("some_identifiying_token", "./examples/ChestClinic.dne")
=> #<Netica::ActiveNetwork:0x58767e95 @network=#<Netica::BayesNetwork:0x4b709592 @current_network=#<Java::NorsysNetica::Net:0x75e82fc2>, @dne_file_path="./examples/ChestClinic.dne">, @token="some_identifiying_token">

View the nodes in the network.

my_network.network.nodes
=> #<Java::NorsysNetica::NodeList:1738447710 size:8 nodes:["NatureNode:VisitAsia", "NatureNode:Tuberculosis", "NatureNode:Smoking", "NatureNode:Cancer", "NatureNode:TbOrCa", "NatureNode:XRay", "NatureNode:Bronchitis", "NatureNode:Dyspnea"]>

Read the value of a Belief node.

tb_node = my_network.network.node("Tuberculosis")
=> #<Java::NorsysNetica::NatureNode:Tuberculosis value:{"present"=>0.010399998165667057, "absent"=>0.9896000027656555}>

tb_node.value("present")
=> 0.010399998165667057

Set the state of the XRay node to Abnormal.

xray_node = my_network.network.node("XRay")
=> #<Java::NorsysNetica::NatureNode:XRay value:{"abnormal"=>0.1102900430560112, "normal"=>0.8897099494934082}>

xray_node.value = "abnormal"
=> "abnormal"

Then, re-read the value of the Belief node.

p tb_node.value("present")
0.09241089224815369
=> 0.09241089224815369

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request

Legal

Netica and Norsys are registered trademarks of Norsys Software Corp.