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diff --git a/src/boost/libs/numeric/odeint/examples/molecular_dynamics.cpp b/src/boost/libs/numeric/odeint/examples/molecular_dynamics.cpp
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+/*
+ [auto_generated]
+ libs/numeric/odeint/examples/molecular_dynamics.cpp
+
+ [begin_description]
+ Molecular dynamics example.
+ [end_description]
+
+ Copyright 2009-2012 Karsten Ahnert
+ Copyright 2009-2012 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 <boost/numeric/odeint.hpp>
+
+#include <vector>
+#include <iostream>
+#include <random>
+
+using namespace boost::numeric::odeint;
+
+
+
+using namespace std;
+#define tab "\t"
+
+const size_t n1 = 16;
+const size_t n2 = 16;
+
+struct md_system
+{
+ static const size_t n = n1 * n2;
+ typedef std::vector< double > vector_type;
+
+ md_system( double a = 0.0 , // strength of harmonic oscillator
+ double gamma = 0.0 , // friction
+ double eps = 0.1 , // interaction strenght
+ double sigma = 1.0 , // interaction radius
+ double xmax = 150.0 , double ymax = 150.0 )
+ : m_a( a ) , m_gamma( gamma )
+ , m_eps( eps ) , m_sigma( sigma )
+ , m_xmax( xmax ) , m_ymax( ymax )
+ { }
+
+ static void init_vector_type( vector_type &x ) { x.resize( 2 * n ); }
+
+ void operator()( vector_type const& x , vector_type const& v , vector_type &a , double t ) const
+ {
+ for( size_t i=0 ; i<n ; ++i )
+ {
+ double diffx = x[i] - 0.5 * m_xmax , diffy = x[i+n] - 0.5 * m_ymax;
+ double r2 = diffx * diffx + diffy * diffy ;
+ double r = std::sqrt( r2 );
+ a[ i ] = - m_a * r * diffx - m_gamma * v[ i ] ;
+ a[ n + i ] = - m_a * r * diffy - m_gamma * v[ n + i ] ;
+ }
+
+ for( size_t i=0 ; i<n ; ++i )
+ {
+ double xi = x[i] , yi = x[n+i];
+ xi = periodic_bc( xi , m_xmax );
+ yi = periodic_bc( yi , m_ymax );
+ for( size_t j=0 ; j<i ; ++j )
+ {
+ double xj = x[j] , yj = x[n+j];
+ xj = periodic_bc( xj , m_xmax );
+ yj = periodic_bc( yj , m_ymax );
+
+ double diffx = ( xj - xi ) , diffy = ( yj - yi );
+ double r = sqrt( diffx * diffx + diffy * diffy );
+ double f = lennard_jones( r );
+ a[ i ] += diffx / r * f;
+ a[ n + i ] += diffy / r * f;
+ a[ j ] -= diffx / r * f;
+ a[ n + j ] -= diffy / r * f;
+ }
+ }
+ }
+
+ void bc( vector_type &x )
+ {
+ for( size_t i=0 ; i<n ; ++i )
+ {
+ x[ i ] = periodic_bc( x[ i ] , m_xmax );
+ x[ i + n ] = periodic_bc( x[ i + n ] , m_ymax );
+ }
+ }
+
+ inline double lennard_jones( double r ) const
+ {
+ double c = m_sigma / r;
+ double c3 = c * c * c;
+ double c6 = c3 * c3;
+ return 4.0 * m_eps * ( -12.0 * c6 * c6 / r + 6.0 * c6 / r );
+ }
+
+ static inline double periodic_bc( double x , double xmax )
+ {
+ return ( x < 0.0 ) ? x + xmax : ( x > xmax ) ? x - xmax : x ;
+ }
+
+ double m_a;
+ double m_gamma;
+ double m_eps ;
+ double m_sigma ;
+ double m_xmax , m_ymax;
+};
+
+
+
+
+
+int main( int argc , char *argv[] )
+{
+ const size_t n = md_system::n;
+ typedef md_system::vector_type vector_type;
+
+
+ std::mt19937 rng;
+ std::normal_distribution<> dist( 0.0 , 1.0 );
+
+ vector_type x , v;
+ md_system::init_vector_type( x );
+ md_system::init_vector_type( v );
+
+ for( size_t i=0 ; i<n1 ; ++i )
+ {
+ for( size_t j=0 ; j<n2 ; ++j )
+ {
+ x[i*n2+j ] = 5.0 + i * 4.0 ;
+ x[i*n2+j+n] = 5.0 + j * 4.0 ;
+ v[i] = dist( rng ) ;
+ v[i+n] = dist( rng ) ;
+ }
+ }
+
+ velocity_verlet< vector_type > stepper;
+ const double dt = 0.025;
+ double t = 0.0;
+ md_system sys;
+ for( size_t oi=0 ; oi<100000 ; ++oi )
+ {
+ for( size_t ii=0 ; ii<100 ; ++ii,t+=dt )
+ stepper.do_step( sys , std::make_pair( std::ref( x ) , std::ref( v ) ) , t , dt );
+ sys.bc( x );
+
+ std::cout << "set size square" << "\n";
+ std::cout << "unset key" << "\n";
+ std::cout << "p [0:" << sys.m_xmax << "][0:" << sys.m_ymax << "] '-' pt 7 ps 0.5" << "\n";
+ for( size_t i=0 ; i<n ; ++i )
+ std::cout << x[i] << " " << x[i+n] << " " << v[i] << " " << v[i+n] << "\n";
+ std::cout << "e" << std::endl;
+ }
+
+
+ return 0;
+}