mcpele/random_coords_displacement.h

#ifndef _MCPELE_RANDOM_COORDS_DISPLACEMENT_H__
#define _MCPELE_RANDOM_COORDS_DISPLACEMENT_H__

#include <random>

#include "mc.h"

namespace mcpele {

class RandomCoordsDisplacement : public TakeStep {
protected:
    size_t m_seed;
    std::mt19937_64 m_generator;
    std::uniform_real_distribution<double> m_real_distribution;
    double m_stepsize;
    size_t m_count;
public:
    RandomCoordsDisplacement(const size_t rseed, const double stepsize=1);
    virtual ~RandomCoordsDisplacement() {}
    virtual void displace(pele::Array<double>& coords, MC* mc) =0;
    size_t get_seed() const {return m_seed;}
    void set_generator_seed(const size_t inp) { m_generator.seed(inp); }
    double expected_mean() const { return 0; }
    double get_stepsize() const { return m_stepsize; }
    double expected_variance(const double ss) const { return ss * ss / static_cast<double>(12); }
    void increase_acceptance(const double factor) { m_stepsize *= factor; }
    void decrease_acceptance(const double factor) { m_stepsize /= factor; }
    size_t get_count() const { return m_count; }
};

class RandomCoordsDisplacementAll : public RandomCoordsDisplacement {
public:
    RandomCoordsDisplacementAll(const size_t rseed, const double stepsize=1);
    virtual ~RandomCoordsDisplacementAll() {}
    virtual void displace(pele::Array<double>& coords, MC* mc);
};

class RandomCoordsDisplacementSingle : public RandomCoordsDisplacement {
    size_t m_nparticles, m_ndim, m_rand_particle;
    std::uniform_int_distribution<size_t> m_int_distribution;
public:
    RandomCoordsDisplacementSingle(const size_t rseed, const size_t nparticles, const size_t ndim, const double stepsize=1);
    virtual ~RandomCoordsDisplacementSingle() {}
    virtual void displace(pele::Array<double>& coords, MC* mc);
    size_t get_rand_particle(){return m_rand_particle;} //dangerous function, should be used only for testing purposes
};

} // namespace mcpele

#endif // #ifndef _MCPELE_RANDOM_COORDS_DISPLACEMENT_H__