[Boost-commit] svn:boost r57043 - sandbox/odeint/boost/numeric/odeint

Subject: [Boost-commit] svn:boost r57043 - sandbox/odeint/boost/numeric/odeint
From: karsten.ahnert_at_[hidden]
Date: 2009-10-21 10:33:45

Author: karsten
Date: 2009-10-21 10:33:45 EDT (Wed, 21 Oct 2009)
New Revision: 57043
URL: http://svn.boost.org/trac/boost/changeset/57043

Log:
added euler.hpp
Added:
   sandbox/odeint/boost/numeric/odeint/euler.hpp   (contents, props changed)

Added: sandbox/odeint/boost/numeric/odeint/euler.hpp
==============================================================================
--- (empty file)
+++ sandbox/odeint/boost/numeric/odeint/euler.hpp	2009-10-21 10:33:45 EDT (Wed, 21 Oct 2009)
@@ -0,0 +1,90 @@
+/* Boost odeint/euler.hpp header file
+ 
+ Copyright 2009 Karsten Ahnert
+ Copyright 2009 Mario Mulansky
+ Copyright 2009 Andre Bergner
+ 
+ This file includes the explicit euler solver for ordinary differential equations.
+
+ It solves any ODE dx/dt = f(x,t) via
+ x(t+dt) = x(t) + dt*f(x,t)
+
+ 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)
+*/
+
+#ifndef BOOST_NUMERIC_ODEINT_EULER_HPP
+#define BOOST_NUMERIC_ODEINT_EULER_HPP
+
+
+namespace boost {
+namespace numeric {
+namespace odeint {
+namespace detail {
+
+    template< class DynamicalSystem ,
+	      class StateIterator ,
+	      class DerivativeIterator ,
+	      class TimeType >
+    void euler_imp( DynamicalSystem system ,
+		    StateIterator state_begin ,
+		    StateIterator state_end ,
+		    DerivativeIterator derivative_begin ,
+		    TimeType time_step ,
+		    TimeType time )
+    {
+	system( state_begin , derivative_begin , time );
+	while( state_begin != state_end ) (*state_begin++) += time_step * (*derivative_begin++);
+    }
+
+} // namespace odeint
+} // namespace numeric
+} // namespace boost
+} // namespace detail
+
+
+
+
+
+
+namespace boost {
+namespace numeric {
+namespace odeint {
+
+    template< class ContainerType >
+    class ode_step_euler
+    {
+
+	ContainerType dxdt;
+
+    public:
+
+	template< class DynamicalSystem , class TimeType>
+	void next_step( DynamicalSystem system , ContainerType &x , TimeType t , TimeType dt )
+	{
+	    if( x.size() != dxdt.size() ) dxdt.resize( x.size() );
+
+	    typename ContainerType::iterator dxdt_iter = dxdt.begin();
+	    typename ContainerType::iterator x_iter = x.begin();
+	    typename ContainerType::iterator x_end = x.end();
+
+	    detail::euler_imp( system , x_iter , x_end , dxdt_iter , dt , t );
+	}
+    };
+
+
+/* ToDo:
+   Write stepper for
+   * fixed size systems
+   * array<T>
+   * system( T* , T* , T )
+ */
+
+
+} // namespace odeint
+} // namespace numeric
+} // namespace boost
+
+
+#endif // BOOST_NUMERIC_ODEINT_EULER_HPP