29 Numerics library [numerics]

29.6 Random number generation [rand]

29.6.8 Random number distribution class templates [rand.dist]

29.6.8.5 Normal distributions [rand.dist.norm]

29.6.8.5.5 Class template fisher_­f_­distribution [rand.dist.norm.f]

A fisher_­f_­distribution random number distribution produces random numbers x≥0 distributed according to the probability density function

p(x|m,n)=Γ((m+n)/2)Γ(m/2)Γ(n/2)(mn)m/2x(m/2)1(1+mxn)(m+n)/2.

template<class RealType = double>
  class fisher_f_distribution {
  public:
    // types
    using result_type = RealType;
    using param_type  = unspecified;

    // constructor and reset functions
    explicit fisher_f_distribution(RealType m = 1, RealType n = 1);
    explicit fisher_f_distribution(const param_type& parm);
    void reset();

    // generating functions
    template<class URBG>
      result_type operator()(URBG& g);
    template<class URBG>
      result_type operator()(URBG& g, const param_type& parm);

    // property functions
    RealType m() const;
    RealType n() const;
    param_type param() const;
    void param(const param_type& parm);
    result_type min() const;
    result_type max() const;
  };

explicit fisher_f_distribution(RealType m = 1, RealType n = 1);

Requires: 0<m and 0<n.

Effects: Constructs a fisher_­f_­distribution object; m and n correspond to the respective parameters of the distribution.

RealType m() const;

Returns: The value of the m parameter with which the object was constructed.

RealType n() const;

Returns: The value of the n parameter with which the object was constructed.