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-rw-r--r--src/boost/libs/numeric/odeint/examples/elliptic_functions.cpp89
1 files changed, 89 insertions, 0 deletions
diff --git a/src/boost/libs/numeric/odeint/examples/elliptic_functions.cpp b/src/boost/libs/numeric/odeint/examples/elliptic_functions.cpp
new file mode 100644
index 000000000..97ba59da5
--- /dev/null
+++ b/src/boost/libs/numeric/odeint/examples/elliptic_functions.cpp
@@ -0,0 +1,89 @@
+/*
+ * elliptic_functions.cpp
+ *
+ * Copyright 2011-2013 Mario Mulansky
+ * Copyright 2011-2012 Karsten Ahnert
+ *
+ * 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 <fstream>
+#include <cmath>
+
+#include <boost/array.hpp>
+
+#include <boost/numeric/odeint/config.hpp>
+
+#include <boost/numeric/odeint.hpp>
+#include <boost/numeric/odeint/stepper/bulirsch_stoer.hpp>
+#include <boost/numeric/odeint/stepper/bulirsch_stoer_dense_out.hpp>
+
+using namespace std;
+using namespace boost::numeric::odeint;
+
+typedef boost::array< double , 3 > state_type;
+
+/*
+ * x1' = x2*x3
+ * x2' = -x1*x3
+ * x3' = -m*x1*x2
+ */
+
+void rhs( const state_type &x , state_type &dxdt , const double t )
+{
+ static const double m = 0.51;
+
+ dxdt[0] = x[1]*x[2];
+ dxdt[1] = -x[0]*x[2];
+ dxdt[2] = -m*x[0]*x[1];
+}
+
+ofstream out;
+
+void write_out( const state_type &x , const double t )
+{
+ out << t << '\t' << x[0] << '\t' << x[1] << '\t' << x[2] << endl;
+}
+
+int main()
+{
+ bulirsch_stoer_dense_out< state_type > stepper( 1E-9 , 1E-9 , 1.0 , 0.0 );
+
+ state_type x1 = {{ 0.0 , 1.0 , 1.0 }};
+
+ double t = 0.0;
+ double dt = 0.01;
+
+ out.open( "elliptic1.dat" );
+ out.precision(16);
+ integrate_const( stepper , rhs , x1 , t , 100.0 , dt , write_out );
+ out.close();
+
+ state_type x2 = {{ 0.0 , 1.0 , 1.0 }};
+
+ out.open( "elliptic2.dat" );
+ out.precision(16);
+ integrate_adaptive( stepper , rhs , x2 , t , 100.0 , dt , write_out );
+ out.close();
+
+ typedef runge_kutta_dopri5< state_type > dopri5_type;
+ typedef controlled_runge_kutta< dopri5_type > controlled_dopri5_type;
+ typedef dense_output_runge_kutta< controlled_dopri5_type > dense_output_dopri5_type;
+
+
+ dense_output_dopri5_type dopri5 = make_dense_output( 1E-9 , 1E-9 , dopri5_type() );
+ //dense_output_dopri5_type dopri5( controlled_dopri5_type( default_error_checker< double >( 1E-9 , 0.0 , 0.0 , 0.0 ) ) );
+
+ state_type x3 = {{ 0.0 , 1.0 , 1.0 }};
+
+ out.open( "elliptic3.dat" );
+ out.precision(16);
+ integrate_adaptive( dopri5 , rhs , x3 , t , 100.0 , dt , write_out );
+ out.close();
+}