DiscreteGen.h

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

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

namespace honey
{


template<class Real>
class DiscreteGen_ : public RandomDist<Real>
{
    typedef RandomDist<Real> Super;
    RandomDist_imports();
    template<class> friend class DiscreteGen_;
    typedef vector<Double> Listd;

    struct Elem
    {
        Double bisector;
        szt indexTwo;
    };
    typedef vector<Elem> Table;

public:

    typedef vector<Real> List;

    DiscreteGen_(RandomGen& gen, List pdf);

    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 _mean; }
    virtual Real variance() const           { return _variance; }

    szt variateMin() const                  { return 0; }
    szt variateMax() const                  { return _pdf.size() > 0 ? _pdf.size()-1 : 0; }

private:
    Listd _pdf;
    Listd _cdf;
    Double _mean;
    Double _variance;
    Table _table;
};

typedef DiscreteGen_<Real>      DiscreteGen;
typedef DiscreteGen_<Float>     DiscreteGen_f;
typedef DiscreteGen_<Double>    DiscreteGen_d;

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

}