1 /*
2 * Copyright 2011-2013 Mario Mulansky
3 * Copyright 2012 Karsten Ahnert
4 *
5 * Distributed under the Boost Software License, Version 1.0.
6 * (See accompanying file LICENSE_1_0.txt or
7 * copy at http://www.boost.org/LICENSE_1_0.txt)
8 */
9
10
11 #include <iostream>
12
13 #include <boost/numeric/odeint.hpp>
14 #include <boost/numeric/ublas/vector.hpp>
15
16 typedef boost::numeric::ublas::vector< double > state_type;
17
lorenz(const state_type & x,state_type & dxdt,const double t)18 void lorenz( const state_type &x , state_type &dxdt , const double t )
19 {
20 const double sigma( 10.0 );
21 const double R( 28.0 );
22 const double b( 8.0 / 3.0 );
23
24 dxdt[0] = sigma * ( x[1] - x[0] );
25 dxdt[1] = R * x[0] - x[1] - x[0] * x[2];
26 dxdt[2] = -b * x[2] + x[0] * x[1];
27 }
28
29 using namespace boost::numeric::odeint;
30
31 //[ublas_main
main()32 int main()
33 {
34 state_type x(3);
35 x[0] = 10.0; x[1] = 5.0 ; x[2] = 0.0;
36 typedef runge_kutta_dopri5< state_type > stepper;
37 integrate_const( make_dense_output< stepper >( 1E-6 , 1E-6 ) , lorenz , x ,
38 0.0 , 10.0 , 0.1 );
39 }
40 //]
41