Contents

require File.expand_path(File.dirname(__FILE__) + '/../../spec_helper')

include Fathom

describe DiscreteNode do
  
  before do
    @dn = DiscreteNode.new(:labels => [1,2,3])
  end
  
  it "should assign :true and :false for labels, if none are provided" do
    lambda{@dn = DiscreteNode.new}.should_not raise_error
    @dn.labels.should eql([:true, :false])
  end
  
  it "should create an array from a single value for its labels" do
    dn = DiscreteNode.new(:labels => 1)
    dn.labels.should eql([1])
  end
  
  it "should take the values and convert them to labels, if there are no labels provided" do
    dn = DiscreteNode.new(:values => [1,2,3])
    dn.labels.should eql([1,2,3])
  end
  
  it "should create a unique list of labels" do
    dn = DiscreteNode.new(:labels => [1,1,2,3,1])
    dn.labels.should eql([1,2,3])
  end
  
  it "should expose the size of the labels" do
    @dn.size.should eql(3)
  end
  
  it "should alias length for size" do
    @dn.length.should eql(3)
  end
  
  it "should have a default distribution of DiscreteUniform" do
    @dn.distribution.should eql(Fathom::Distributions::DiscreteUniform)
  end
  
  it "should be able to produce a random variable from the discrete distribution" do
    @dn = DiscreteNode.new(:labels => [1,2])
    # 9.31322574615479e-10 chance of failing
    30.times.map {@dn.rand}.uniq.sort.should eql([1,2])
  end
  
  it "should offer a uniform likelihood" do
    @dn.likelihood(:anything).to_a.should eql([1.0, 1.0, 1.0])
  end
  
  it "should offer an alias of l for likelihood" do
    @dn.l(:anything).to_a.should eql([1.0, 1.0, 1.0])
  end
end

Version data entries

6 entries across 6 versions & 1 rubygems

Version	Path
fathom-0.3.7	spec/fathom/node/discrete_node_spec.rb
fathom-0.3.6	spec/fathom/node/discrete_node_spec.rb
fathom-0.3.4	spec/fathom/node/discrete_node_spec.rb
fathom-0.3.3	spec/fathom/node/discrete_node_spec.rb
fathom-0.3.2	spec/fathom/node/discrete_node_spec.rb
fathom-0.3.1	spec/fathom/node/discrete_node_spec.rb