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/* Boost check_gmp.cpp test file
Copyright 2010-2012 Mario Mulansky
Copyright 2011-2012 Karsten Ahnert
This file tests the odeint library with the gmp arbitrary precision types
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)
*/
#define BOOST_TEST_MODULE odeint_gmp
#include <iostream>
#include <gmpxx.h>
#include <boost/test/unit_test.hpp>
#include <boost/array.hpp>
#include <boost/mpl/vector.hpp>
#include <boost/numeric/odeint.hpp>
//#include <boost/numeric/odeint/algebra/vector_space_algebra.hpp>
using namespace boost::unit_test;
using namespace boost::numeric::odeint;
namespace mpl = boost::mpl;
const int precision = 1024;
typedef mpf_class value_type;
typedef mpf_class state_type;
//provide min, max and pow functions for mpf types - required for controlled steppers
value_type min( const value_type a , const value_type b )
{
if( a<b ) return a;
else return b;
}
value_type max( const value_type a , const value_type b )
{
if( a>b ) return a;
else return b;
}
value_type pow( const value_type a , const value_type b )
{
// do calculation in double precision
return value_type( std::pow( a.get_d() , b.get_d() ) );
}
//provide vector_space reduce:
namespace boost { namespace numeric { namespace odeint {
template<>
struct vector_space_reduce< state_type >
{
template< class Op >
state_type operator()( state_type x , Op op , state_type init ) const
{
init = op( init , x );
return init;
}
};
} } }
void constant_system( const state_type &x , state_type &dxdt , value_type t )
{
dxdt = value_type( 1.0 , precision );
}
/* check runge kutta stepers */
typedef mpl::vector<
euler< state_type , value_type , state_type , value_type , vector_space_algebra > ,
modified_midpoint< state_type , value_type , state_type , value_type , vector_space_algebra > ,
runge_kutta4< state_type , value_type , state_type , value_type , vector_space_algebra > ,
runge_kutta4_classic< state_type , value_type , state_type , value_type , vector_space_algebra > ,
runge_kutta_cash_karp54_classic< state_type , value_type , state_type , value_type , vector_space_algebra > ,
runge_kutta_cash_karp54< state_type , value_type , state_type , value_type , vector_space_algebra > ,
runge_kutta_dopri5< state_type , value_type , state_type , value_type , vector_space_algebra > ,
runge_kutta_fehlberg78< state_type , value_type , state_type , value_type , vector_space_algebra >
> stepper_types;
template< class Stepper >
struct perform_runge_kutta_test {
void operator()( void )
{
/* We have to specify the desired precision in advance! */
mpf_set_default_prec( precision );
mpf_t eps_ , unity;
mpf_init( eps_ ); mpf_init( unity );
mpf_set_d( unity , 1.0 );
mpf_div_2exp( eps_ , unity , precision-1 ); // 2^(-precision+1) : smallest number that can be represented with used precision
value_type eps( eps_ );
Stepper stepper;
state_type x;
x = 0.0;
stepper.do_step( constant_system , x , 0.0 , 0.1 );
BOOST_MESSAGE( eps );
BOOST_CHECK_MESSAGE( abs( x - value_type( 0.1 , precision ) ) < eps , x - 0.1 );
}
};
BOOST_AUTO_TEST_CASE_TEMPLATE( runge_kutta_stepper_test , Stepper , stepper_types )
{
perform_runge_kutta_test< Stepper > tester;
tester();
}
/* check controlled steppers */
typedef mpl::vector<
controlled_runge_kutta< runge_kutta_cash_karp54_classic< state_type , value_type , state_type , value_type , vector_space_algebra > > ,
controlled_runge_kutta< runge_kutta_dopri5< state_type , value_type , state_type , value_type , vector_space_algebra > > ,
controlled_runge_kutta< runge_kutta_fehlberg78< state_type , value_type , state_type , value_type , vector_space_algebra > > ,
bulirsch_stoer< state_type , value_type , state_type , value_type , vector_space_algebra >
> controlled_stepper_types;
template< class Stepper >
struct perform_controlled_test {
void operator()( void )
{
mpf_set_default_prec( precision );
mpf_t eps_ , unity;
mpf_init( eps_ ); mpf_init( unity );
mpf_set_d( unity , 1.0 );
mpf_div_2exp( eps_ , unity , precision-1 ); // 2^(-precision+1) : smallest number that can be represented with used precision
value_type eps( eps_ );
Stepper stepper;
state_type x;
x = 0.0;
value_type t(0.0);
value_type dt(0.1);
stepper.try_step( constant_system , x , t , dt );
BOOST_MESSAGE( eps );
BOOST_CHECK_MESSAGE( abs( x - value_type( 0.1 , precision ) ) < eps , x - 0.1 );
}
};
BOOST_AUTO_TEST_CASE_TEMPLATE( controlled_stepper_test , Stepper , controlled_stepper_types )
{
perform_controlled_test< Stepper > tester;
tester();
}
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