diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 18:24:20 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 18:24:20 +0000 |
commit | 483eb2f56657e8e7f419ab1a4fab8dce9ade8609 (patch) | |
tree | e5d88d25d870d5dedacb6bbdbe2a966086a0a5cf /src/boost/libs/numeric/odeint/examples/stiff_system.cpp | |
parent | Initial commit. (diff) | |
download | ceph-upstream.tar.xz ceph-upstream.zip |
Adding upstream version 14.2.21.upstream/14.2.21upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/boost/libs/numeric/odeint/examples/stiff_system.cpp')
-rw-r--r-- | src/boost/libs/numeric/odeint/examples/stiff_system.cpp | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/src/boost/libs/numeric/odeint/examples/stiff_system.cpp b/src/boost/libs/numeric/odeint/examples/stiff_system.cpp new file mode 100644 index 00000000..ca71f660 --- /dev/null +++ b/src/boost/libs/numeric/odeint/examples/stiff_system.cpp @@ -0,0 +1,118 @@ +/* + * 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; +} |