module Distribution
  module F
    module Statistics2_
    class << self
      # Return the P-value of the corresponding integral with 
      # k degrees of freedom
      #
      #   Distribution::F.p_value(0.95,1,2)
      # Statistics2 have some problem with extreme values
      def p_value(pr,k1,k2)
        Statistics2.pfdist(k1,k2, pr)
      end
      # F cumulative distribution function (cdf).
      # 
      # Returns the integral of F-distribution 
      # with k1 and k2 degrees of freedom
      # over [0, x].
      #   Distribution::F.cdf(20,3,2)
      # 
      def cdf(x, k1, k2)
        Statistics2.fdist(k1, k2,x)
      end
    end
    end
  end
end