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- /*
- * lorenz_mp.cpp
- *
- * This example demonstrates how odeint can be used with boost.multiprecision.
- *
- * Copyright 2011-2012 Karsten Ahnert
- * Copyright 2013 Mario Mulansky
- *
- * 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>
- //[ mp_lorenz_defs
- #include <boost/numeric/odeint.hpp>
- #include <boost/multiprecision/cpp_dec_float.hpp>
- using namespace std;
- using namespace boost::numeric::odeint;
- typedef boost::multiprecision::cpp_dec_float_50 value_type;
- typedef boost::array< value_type , 3 > state_type;
- //]
- //[ mp_lorenz_rhs
- struct lorenz
- {
- void operator()( const state_type &x , state_type &dxdt , value_type t ) const
- {
- const value_type sigma( 10 );
- const value_type R( 28 );
- const value_type b( value_type( 8 ) / value_type( 3 ) );
- dxdt[0] = sigma * ( x[1] - x[0] );
- dxdt[1] = R * x[0] - x[1] - x[0] * x[2];
- dxdt[2] = -b * x[2] + x[0] * x[1];
- }
- };
- //]
- struct streaming_observer
- {
- std::ostream& m_out;
- streaming_observer( std::ostream &out ) : m_out( out ) { }
- template< class State , class Time >
- void operator()( const State &x , Time t ) const
- {
- m_out << t;
- for( size_t i=0 ; i<x.size() ; ++i ) m_out << "\t" << x[i] ;
- m_out << "\n";
- }
- };
- int main( int argc , char **argv )
- {
- //[ mp_lorenz_int
- state_type x = {{ value_type( 10.0 ) , value_type( 10.0 ) , value_type( 10.0 ) }};
- cout.precision( 50 );
- integrate_const( runge_kutta4< state_type , value_type >() ,
- lorenz() , x , value_type( 0.0 ) , value_type( 10.0 ) , value_type( value_type( 1.0 ) / value_type( 10.0 ) ) ,
- streaming_observer( cout ) );
- //]
- return 0;
- }
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