simulation.hpp

#pragma once
 
#include <Eigen/Core>
#include <Eigen/SparseCore>
#include <random>
 
#include "interface.hpp"
#include "poisson.hpp"
#include "particles.hpp"
 
/**
 * @class Simulation
 * @brief Main driver class coordinating IO, Poisson solve, particle push,
 *        and data storage for a 1D PIC simulation.
 */
class Simulation {
 
private:
 
    /** @brief Interface for input/output handling. */
    const IOInterface* m_interface;
    /** @brief Poisson equation solver for field computation. */
    PoissonSolver* m_poisson;
    /** @brief Particle container and pusher. */
    Particles* m_particles;
 
    /** @brief Mersenne Twister RNG. */
    std::mt19937 m_rng;
 
    /** @brief Number of mesh cells. */
    int m_cellnumber;
    /** @brief Total number of timesteps. */
    int m_timesteps;
    /** @brief Total number of energy bins for postproc. */
    int m_bins;
    /** @brief Current timestep index. */
    int m_timestep_idx = 0;
 
    /** @brief Global time vector (size = timesteps). */
    Eigen::VectorXd m_time;
    /** @brief Cell widths. */
    Eigen::VectorXd m_dx;
    /** @brief Nodal positions. */
    Eigen::VectorXd m_nodes;
 
    /** @brief Charge density history: rows=time, cols=nodes. */
    Eigen::MatrixXd m_rho;
    /** @brief Electrostatic potential history. */
    Eigen::MatrixXd m_phi;
    /** @brief Electric field history (cell-centered). */
    Eigen::MatrixXd m_efield;
 
    /** @brief Collected particle fluxes per timestep. */
    Eigen::MatrixX4d m_fluxes;
 
    Eigen::MatrixXd m_energy_dist;
public:
 
    /**
     * @brief Construct the simulation from an IO interface.
     * @param interface Pointer to configuration and IO handler.
     */
    explicit Simulation(const IOInterface* interface);
 
    /**
     * @brief Execute the complete PIC time integration loop.
     */
    void run();
 
    /**
     * @brief Write simulation results to output files.
     */
    void postprocess();
};