/* * rosenbrock4.cpp * * Copyright 2010-2012 Mario Mulansky * Copyright 2011-2012 Karsten Ahnert * Copyright 2012 Andreas Angelopoulos * * 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 #include #include #include #include #include using namespace std; using namespace boost::numeric::odeint; namespace phoenix = boost::phoenix; //[ stiff_system_definition typedef boost::numeric::ublas::vector< double > vector_type; typedef boost::numeric::ublas::matrix< double > matrix_type; struct stiff_system { void operator()( const vector_type &x , vector_type &dxdt , double /* t */ ) { dxdt[ 0 ] = -101.0 * x[ 0 ] - 100.0 * x[ 1 ]; dxdt[ 1 ] = x[ 0 ]; } }; struct stiff_system_jacobi { void operator()( const vector_type & /* x */ , matrix_type &J , const double & /* t */ , vector_type &dfdt ) { J( 0 , 0 ) = -101.0; J( 0 , 1 ) = -100.0; J( 1 , 0 ) = 1.0; J( 1 , 1 ) = 0.0; dfdt[0] = 0.0; dfdt[1] = 0.0; } }; //] /* //[ stiff_system_alternative_definition typedef boost::numeric::ublas::vector< double > vector_type; typedef boost::numeric::ublas::matrix< double > matrix_type; struct stiff_system { template< class State > void operator()( const State &x , State &dxdt , double t ) { ... } }; struct stiff_system_jacobi { template< class State , class Matrix > void operator()( const State &x , Matrix &J , const double &t , State &dfdt ) { ... } }; //] */ int main( int argc , char **argv ) { // typedef rosenbrock4< double > stepper_type; // typedef rosenbrock4_controller< stepper_type > controlled_stepper_type; // typedef rosenbrock4_dense_output< controlled_stepper_type > dense_output_type; //[ integrate_stiff_system vector_type x( 2 , 1.0 ); size_t num_of_steps = integrate_const( make_dense_output< rosenbrock4< double > >( 1.0e-6 , 1.0e-6 ) , make_pair( stiff_system() , stiff_system_jacobi() ) , x , 0.0 , 50.0 , 0.01 , cout << phoenix::arg_names::arg2 << " " << phoenix::arg_names::arg1[0] << "\n" ); //] clog << num_of_steps << endl; // typedef runge_kutta_dopri5< vector_type > dopri5_type; // typedef controlled_runge_kutta< dopri5_type > controlled_dopri5_type; // typedef dense_output_runge_kutta< controlled_dopri5_type > dense_output_dopri5_type; //[ integrate_stiff_system_alternative vector_type x2( 2 , 1.0 ); size_t num_of_steps2 = integrate_const( make_dense_output< runge_kutta_dopri5< vector_type > >( 1.0e-6 , 1.0e-6 ) , stiff_system() , x2 , 0.0 , 50.0 , 0.01 , cout << phoenix::arg_names::arg2 << " " << phoenix::arg_names::arg1[0] << "\n" ); //] clog << num_of_steps2 << endl; return 0; }