RandomNumberGenerator.hpp

/*

Copyright (c) 2005-2012, University of Oxford.
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This file is part of Chaste.

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modification, are permitted provided that the following conditions are met:
 * Redistributions of source code must retain the above copyright notice,
   this list of conditions and the following disclaimer.
 * Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
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   contributors may be used to endorse or promote products derived from this
   software without specific prior written permission.

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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
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*/

#ifndef RANDOMNUMBERGENERATORS_HPP_
#define RANDOMNUMBERGENERATORS_HPP_

#include <boost/shared_ptr.hpp>

#include "ChasteSerialization.hpp"
#include "SerializableSingleton.hpp"
#include <boost/serialization/split_member.hpp>

class RandomNumberGenerator : public SerializableSingleton<RandomNumberGenerator>
{
private:

    int mSeed;

    long unsigned mTimesCalled;

    static RandomNumberGenerator* mpInstance;

    double mWorkingMem1;

    double mWorkingMem2;

    double mWorkingMemW;

    double mRandNum2;

    bool mUseLastNum;

    friend class boost::serialization::access;
    template<class Archive>
    void save(Archive & archive, const unsigned int version) const
    {
        archive & mSeed;
        archive & mTimesCalled;
        archive & mUseLastNum;
        archive & mRandNum2;
    }

    template<class Archive>
    void load(Archive & archive, const unsigned int version)
    {
        archive & mSeed;
        archive & mTimesCalled;
        archive & mUseLastNum;
        archive & mRandNum2;

        // Reset the random number generator to use the correct seed
        srandom(mSeed);

        /*
         * Call it the correct number of times to put it in the same state
         * as it used to be.
         */
        for (long unsigned i=0; i<mTimesCalled; i++)
        {
            random();
        }
    }
    BOOST_SERIALIZATION_SPLIT_MEMBER()

protected:

    RandomNumberGenerator();

public:

    double StandardNormalRandomDeviate();

    double NormalRandomDeviate(double mean, double sd);

    double ranf();

    unsigned randMod(unsigned base);


    template <class T>
    void Shuffle(std::vector<boost::shared_ptr<T> >& rValues)
    {
        unsigned num = rValues.size();
        if (num == 0)
        {
            return;
        }
        for (unsigned end=num-1; end>0; end--)
        {
            // Pick a random integer from {0,..,end}
            unsigned k = RandomNumberGenerator::Instance()->randMod(end+1);
            boost::shared_ptr<T> temp = rValues[end];
            rValues[end] = rValues[k];
            rValues[k] = temp;
        }
    }
    void Shuffle(unsigned num, std::vector<unsigned>& rValues);

    static RandomNumberGenerator* Instance();

    static void Destroy();

    void Reseed(int seed);
};

#endif /*RANDOMNUMBERGENERATORS_HPP_*/