119 lines
3.0 KiB
C++
119 lines
3.0 KiB
C++
/*
|
|
* 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 <iostream>
|
|
#include <fstream>
|
|
#include <utility>
|
|
|
|
#include <boost/numeric/odeint.hpp>
|
|
|
|
#include <boost/phoenix/core.hpp>
|
|
|
|
#include <boost/phoenix/core.hpp>
|
|
#include <boost/phoenix/operator.hpp>
|
|
|
|
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;
|
|
}
|