/* * gsl_rk4_lorenz.cpp * * Copyright 2011 Mario Mulansky * Copyright 2012 Karsten Ahnert * * Distributed under the Boost Software License, Version 1.0. * (See accompanying file LICENSE_1_0.txt or * copy at http://www.boost.org/LICENSE_1_0.txt) */ #include #include "rk_performance_test_case.hpp" #include "lorenz_gsl.hpp" const size_t dim = 3; class gsl_wrapper { public: gsl_wrapper() { m_s = gsl_odeiv_step_alloc( gsl_odeiv_step_rk4 , dim); m_sys.function = lorenz_gsl; m_sys.jacobian = 0; m_sys.dimension = dim; m_sys.params = 0; } void reset_init_cond() { m_x[0] = 10.0 * rand() / RAND_MAX; m_x[1] = 10.0 * rand() / RAND_MAX; m_x[2] = 10.0 * rand() / RAND_MAX; m_t = 0.0; } inline void do_step( const double dt ) { gsl_odeiv_step_apply ( m_s , m_t , dt , m_x , m_x_err , 0 , 0 , &m_sys ); //m_t += dt; } double state( const size_t i ) const { return m_x[i]; } ~gsl_wrapper() { gsl_odeiv_step_free( m_s ); } private: double m_x[dim]; double m_x_err[dim]; double m_t; gsl_odeiv_step *m_s; gsl_odeiv_system m_sys; }; int main() { gsl_wrapper stepper; run( stepper , 20000000 / 3 , 1E-10 * 3); }