runge_kutta4.hpp

Go to the documentation of this file.

#pragma once

 
#include <string_view>
 
#include "orrery/core/particle_data.hpp"
#include "orrery/core/types.hpp"
#include "orrery/core/vec3_array.hpp"
#include "orrery/integrators/acceleration_field.hpp"
#include "orrery/integrators/integrator.hpp"
 
namespace orrery::integrators {

class RungeKutta4 final : public Integrator {
public:
    void step(core::ParticleData& data, core::Real timestep, AccelerationField& field) override;
 
    [[nodiscard]] std::string_view name() const noexcept override { return "RK4"; }
 
    [[nodiscard]] int order() const noexcept override { return 4; }
 
    [[nodiscard]] bool is_symplectic() const noexcept override { return false; }

    [[nodiscard]] core::Index force_evaluations_per_step() const noexcept override { return 4; }
 
private:
    void evaluate_stage(core::ParticleData& data, AccelerationField& field, core::Real scale,
                        core::Real weight);
 
    core::Vec3Array initial_positions_;
    core::Vec3Array initial_velocities_;
    core::Vec3Array position_derivative_sum_;
    core::Vec3Array velocity_derivative_sum_;
};
 
} // namespace orrery::integrators