Merge commit '4ebe6417a5fce5f0994fc0c31bebf732be96a07c' as 'boost'

boost/libs/numeric/odeint/test/euler_stepper.cpp

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+/*
+ [auto_generated]
+ libs/numeric/odeint/test/euler_stepper.cpp
+
+ [begin_description]
+ This file tests explicit Euler stepper.
+ [end_description]
+
+ Copyright 2011 Mario Mulansky
+ Copyright 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)
+ */
+
+
+#define BOOST_TEST_MODULE odeint_explicit_euler
+
+#include <boost/test/unit_test.hpp>
+
+#include <utility>
+#include <iostream>
+#include <vector>
+
+#include <boost/numeric/odeint/stepper/euler.hpp>
+#include <boost/numeric/odeint/algebra/range_algebra.hpp>
+
+using namespace boost::unit_test;
+using namespace boost::numeric::odeint;
+
+// test with own vector implementation
+
+class my_vec : public std::vector< double > {
+
+public:
+
+    my_vec() : std::vector< double >()
+        { }
+
+    my_vec( const my_vec &x ) : std::vector< double >( x )
+        { }
+
+
+    my_vec( size_t dim )
+        : std::vector< double >( dim )
+    { }
+
+};
+
+namespace boost {
+namespace numeric {
+namespace odeint {
+
+template<>
+struct is_resizeable< my_vec >
+{
+    //struct type : public boost::true_type { };
+    typedef boost::true_type type;
+    const static bool value = type::value;
+};
+} } }
+
+typedef double value_type;
+//typedef std::vector< value_type > state_type;
+typedef my_vec state_type;
+
+/* use functors, because functions don't work with msvc 10, I guess this is a bug */
+struct sys
+{
+    void operator()( const state_type &x , state_type &dxdt , const value_type t ) const
+    {
+        std::cout << "sys start " << dxdt.size() << std::endl;
+        dxdt[0] = x[0] + 2 * x[1];
+        dxdt[1] = x[1];
+        std::cout << "sys done" << std::endl;
+    }
+};
+
+
+BOOST_AUTO_TEST_SUITE( explicit_euler_test )
+
+BOOST_AUTO_TEST_CASE( test_euler )
+{
+    range_algebra algebra;
+    euler< state_type > stepper( algebra );
+    state_type x( 2 );
+    x[0] = 0.0; x[1] = 1.0;
+
+    std::cout << "initialized" << std::endl;
+
+    const value_type eps = 1E-12;
+    const value_type dt = 0.1;
+
+    stepper.do_step( sys() , x , 0.0 , dt );
+
+    using std::abs;
+
+    // compare with analytic solution of above system
+    BOOST_CHECK_MESSAGE( abs( x[0] - 2.0*1.0*dt ) < eps , x[0] - 2.0*1.0*dt );
+    BOOST_CHECK_MESSAGE( abs( x[1] - (1.0 + dt) ) < eps , x[1] - (1.0+dt) );
+
+}
+
+BOOST_AUTO_TEST_SUITE_END()