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/* Boost libs/numeric/odeint/examples/integrate_times.cpp
Copyright 2009-2014 Karsten Ahnert
Copyright 2009-2014 Mario Mulansky
example for the use of integrate_times
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 <boost/numeric/odeint.hpp>
using namespace std;
using namespace boost::numeric::odeint;
/*
* simple 1D ODE
*/
void rhs( const double x , double &dxdt , const double t )
{
dxdt = 3.0/(2.0*t*t) + x/(2.0*t);
}
void write_cout( const double &x , const double t )
{
cout << t << '\t' << x << endl;
}
// state_type = double
typedef runge_kutta_dopri5< double > stepper_type;
const double dt = 0.1;
int main()
{
// create a vector with observation time points
std::vector<double> times( 91 );
for( size_t i=0 ; i<times.size() ; ++i )
times[i] = 1.0 + dt*i;
double x = 0.0; //initial value x(1) = 0
// we can provide the observation time as a boost range (i.e. the vector)
integrate_times( make_controlled( 1E-12 , 1E-12 , stepper_type() ) , rhs ,
x , times , dt , write_cout );
// or as two iterators
//integrate_times( make_controlled( 1E-12 , 1E-12 , stepper_type() ) , rhs ,
// x , times.begin() , times.end() , dt , write_cout );
}
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