Binomial.h

Go to the documentation of this file.

// Honeycomb, Copyright (C) 2015 NewGamePlus Inc.  Distributed under the Boost Software License v1.0.
#pragma once

#include "Honey/Math/Random/Dist/Beta.h"

namespace honey
{


template<class Real>
class Binomial_ : public RandomDist<Real>
{
    typedef RandomDist<Real> Super;
    RandomDist_imports();
    template<class> friend class Binomial_;
    typedef typename Numeral<Real>::Int Int;
    typedef GammaFunc_<Double> GammaFunc;
    typedef Beta_<Double> Beta;
    
public:
    Binomial_(RandomGen& gen, Int n, Real p)    : RandomDist<Real>(gen), n(n), p(p) { assert(n > 0 && p >= 0 && p <= 1); }

    virtual Real next() const;
    virtual Real pdf(Real x) const;
    virtual Real cdf(Real x) const;
    virtual Real cdfInv(Real P) const;
    virtual Real mean() const                   { return n*p; }
    virtual Real variance() const               { return n*p*(1-p); }
    

    static Real trialProb(Int x, Int n, Real P);

    Int n;
    Real p;
};

typedef Binomial_<Real>      Binomial;
typedef Binomial_<Float>     Binomial_f;
typedef Binomial_<Double>    Binomial_d;

extern template class Binomial_<Float>;
extern template class Binomial_<Double>;

}