require File.expand_path(File.join(File.dirname(__FILE__), '..', 'fathom'))

=begin
  A DataNode is a node generated from data itself.  It stores the data and reveals some statistical 
  measurements for the data.  It expects an array or vector of values and generates a vector on demans.
=end
class Fathom::DataNode

  include NodeUtilities
  
  attr_reader :values, :name, :distribution, :confidence_interval
  
  def initialize(opts={})
    @values = opts[:values]
    raise ArgumentError, "Must provided values: DataNode.new(:values => [...])" unless self.values
    @name = opts[:name]
    @distribution = opts[:distribution]
  end
  
  alias :ci :confidence_interval
  
  def vector
    @vector ||= GSL::Vector.ary_to_gv(self.values)
  end
  
  def standard_deviation
    @standard_deviation ||= vector.sd
  end
  alias :sd :standard_deviation
  alias :std :standard_deviation
  
  def mean
    @mean ||= vector.mean
  end
  
  def rand
    rng.gaussian(std) + mean
  end
  
  protected
    def rng
      @rng ||= GSL::Rng.alloc
    end
    
end

if __FILE__ == $0
  include Fathom
  # TODO: Is there anything you want to do to run this file on its own?
  # DataNode.new
end