boost/numeric/odeint/stepper/adaptive_adams_bashforth_moulton.hpp
/*
boost/numeric/odeint/stepper/detail/adaptive_adams_bashforth_moulton.hpp
[begin_description]
Implemetation of an adaptive adams bashforth moulton stepper.
Used as the stepper for the controlled adams bashforth moulton stepper.
[end_description]
Copyright 2017 Valentin Noah Hartmann
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)
*/
#ifndef BOOST_NUMERIC_ODEINT_STEPPER_ADAPTIVE_ADAMS_BASHFORTH_MOULTON_HPP_INCLUDED
#define BOOST_NUMERIC_ODEINT_STEPPER_ADAPTIVE_ADAMS_BASHFORTH_MOULTON_HPP_INCLUDED
#include <boost/numeric/odeint/stepper/detail/adaptive_adams_coefficients.hpp>
#include <boost/numeric/odeint/util/unwrap_reference.hpp>
#include <boost/numeric/odeint/util/bind.hpp>
#include <boost/numeric/odeint/util/copy.hpp>
#include <boost/numeric/odeint/algebra/default_operations.hpp>
#include <boost/numeric/odeint/algebra/algebra_dispatcher.hpp>
#include <boost/numeric/odeint/algebra/operations_dispatcher.hpp>
#include <boost/numeric/odeint/util/state_wrapper.hpp>
#include <boost/numeric/odeint/util/is_resizeable.hpp>
#include <boost/numeric/odeint/util/resizer.hpp>
#include <boost/numeric/odeint/stepper/stepper_categories.hpp>
#include <boost/numeric/odeint/stepper/base/algebra_stepper_base.hpp>
#include <boost/numeric/odeint/stepper/detail/rotating_buffer.hpp>
namespace boost {
namespace numeric {
namespace odeint {
template<
size_t Steps,
class State,
class Value = double,
class Deriv = State,
class Time = Value,
class Algebra = typename algebra_dispatcher< State >::algebra_type ,
class Operations = typename operations_dispatcher< State >::operations_type,
class Resizer = initially_resizer
>
class adaptive_adams_bashforth_moulton: public algebra_stepper_base< Algebra , Operations >
{
public:
static const size_t steps = Steps;
typedef unsigned short order_type;
static const order_type order_value = steps;
typedef State state_type;
typedef Value value_type;
typedef Deriv deriv_type;
typedef Time time_type;
typedef state_wrapper< state_type > wrapped_state_type;
typedef state_wrapper< deriv_type > wrapped_deriv_type;
typedef algebra_stepper_base< Algebra , Operations > algebra_stepper_base_type;
typedef typename algebra_stepper_base_type::algebra_type algebra_type;
typedef typename algebra_stepper_base_type::operations_type operations_type;
typedef Resizer resizer_type;
typedef error_stepper_tag stepper_category;
typedef detail::adaptive_adams_coefficients< Steps , Deriv , Value , Time , Algebra , Operations , Resizer > coeff_type;
typedef adaptive_adams_bashforth_moulton< Steps , State , Value , Deriv , Time , Algebra , Operations , Resizer > stepper_type;
order_type order() const { return order_value; };
order_type stepper_order() const { return order_value + 1; };
order_type error_order() const { return order_value; };
adaptive_adams_bashforth_moulton( const algebra_type &algebra = algebra_type() )
:algebra_stepper_base_type( algebra ), m_coeff(),
m_dxdt_resizer(), m_xnew_resizer(), m_xerr_resizer()
{};
template< class System >
void do_step(System system, state_type &inOut, time_type t, time_type dt )
{
m_xnew_resizer.adjust_size( inOut , detail::bind( &stepper_type::template resize_xnew_impl< state_type > , detail::ref( *this ) , detail::_1 ) );
do_step(system, inOut, t, m_xnew.m_v, dt, m_xerr.m_v);
boost::numeric::odeint::copy( m_xnew.m_v , inOut);
};
template< class System >
void do_step(System system, const state_type &in, time_type t, state_type &out, time_type dt )
{
do_step(system, in, t, out, dt, m_xerr.m_v);
};
template< class System >
void do_step(System system, state_type &inOut, time_type t, time_type dt, state_type &xerr)
{
m_xnew_resizer.adjust_size( inOut , detail::bind( &stepper_type::template resize_xnew_impl< state_type > , detail::ref( *this ) , detail::_1 ) );
do_step(system, inOut, t, m_xnew.m_v, dt, xerr);
boost::numeric::odeint::copy( m_xnew.m_v , inOut);
};
template< class System >
void do_step(System system, const state_type &in, time_type t, state_type &out, time_type dt , state_type &xerr)
{
do_step_impl(system, in, t, out, dt, xerr);
system(out, m_dxdt.m_v, t+dt);
m_coeff.do_step(m_dxdt.m_v);
m_coeff.confirm();
if(m_coeff.m_eo < order_value)
{
m_coeff.m_eo ++;
}
};
template< class ExplicitStepper, class System >
void initialize(ExplicitStepper stepper, System system, state_type &inOut, time_type &t, time_type dt)
{
reset();
dt = dt/static_cast< time_type >(order_value);
m_dxdt_resizer.adjust_size( inOut , detail::bind( &stepper_type::template resize_dxdt_impl< state_type > , detail::ref( *this ) , detail::_1 ) );
system( inOut , m_dxdt.m_v , t );
for( size_t i=0 ; i<order_value; ++i )
{
stepper.do_step_dxdt_impl( system, inOut, m_dxdt.m_v, t, dt );
system( inOut , m_dxdt.m_v , t + dt);
m_coeff.predict(t, dt);
m_coeff.do_step(m_dxdt.m_v);
m_coeff.confirm();
t += dt;
if(m_coeff.m_eo < order_value)
{
++m_coeff.m_eo;
}
}
};
template< class System >
void initialize(System system, state_type &inOut, time_type &t, time_type dt)
{
reset();
dt = dt/static_cast< time_type >(order_value);
for(size_t i=0; i<order_value; ++i)
{
this->do_step(system, inOut, t, dt);
t += dt;
};
};
template< class System >
void do_step_impl(System system, const state_type & in, time_type t, state_type & out, time_type &dt, state_type &xerr)
{
size_t eO = m_coeff.m_eo;
m_xerr_resizer.adjust_size( in , detail::bind( &stepper_type::template resize_xerr_impl< state_type > , detail::ref( *this ) , detail::_1 ) );
m_dxdt_resizer.adjust_size( in , detail::bind( &stepper_type::template resize_dxdt_impl< state_type > , detail::ref( *this ) , detail::_1 ) );
m_coeff.predict(t, dt);
if (m_coeff.m_steps_init == 1)
{
system(in, m_dxdt.m_v, t);
m_coeff.do_step(m_dxdt.m_v, 1);
}
boost::numeric::odeint::copy( in , out );
for(size_t i=0; i<eO; ++i)
{
this->m_algebra.for_each3(out, out, m_coeff.phi[1][i].m_v,
typename Operations::template scale_sum2<double, double>(1.0, dt*m_coeff.g[i]*m_coeff.beta[0][i]));
}
system(out, m_dxdt.m_v, t+dt);
m_coeff.do_step(m_dxdt.m_v);
this->m_algebra.for_each3(out, out, m_coeff.phi[0][eO].m_v,
typename Operations::template scale_sum2<double, double>(1.0, dt*m_coeff.g[eO]));
// error for current order
this->m_algebra.for_each2(xerr, m_coeff.phi[0][eO].m_v,
typename Operations::template scale_sum1<double>(dt*(m_coeff.g[eO])));
};
const coeff_type& coeff() const { return m_coeff; };
coeff_type & coeff() { return m_coeff; };
void reset() { m_coeff.reset(); };
const deriv_type & dxdt() const { return m_dxdt.m_v; };
private:
template< class StateType >
bool resize_dxdt_impl( const StateType &x )
{
return adjust_size_by_resizeability( m_dxdt, x, typename is_resizeable<deriv_type>::type() );
};
template< class StateType >
bool resize_xnew_impl( const StateType &x )
{
return adjust_size_by_resizeability( m_xnew, x, typename is_resizeable<state_type>::type() );
};
template< class StateType >
bool resize_xerr_impl( const StateType &x )
{
return adjust_size_by_resizeability( m_xerr, x, typename is_resizeable<state_type>::type() );
};
coeff_type m_coeff;
resizer_type m_dxdt_resizer;
resizer_type m_xnew_resizer;
resizer_type m_xerr_resizer;
wrapped_deriv_type m_dxdt;
wrapped_state_type m_xnew;
wrapped_state_type m_xerr;
};
} // odeint
} // numeric
} // boost
#endif