RKF45method.h

//
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//                          RKF45method.h 
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/*! 
    \class RKF45method 
    \brief RKF45method is a  class for creating approximate 
    solutions of systems of autonomous ordinary differential equations using 
    an implementation of the Runge-Kutta Fehlberg method of order 4 and 5.  
  
   <p>The solution procedure is a  Runge-Kutta Fehlberg method whose 
   mplementation is provided by the routine rkf45 written by 
   H.A. Watts and L.F. Shampine at Sandia Laboratories, 
   Albuquerque, New Mexico. 
 
   <p>The version used is an f2c translation of the fortran routine 
   obtained from www.netlib.org. This translated version has
   been appended with the f2c support routines required for 
   compilation (so that the complete f2c support libraries need
   not be included). 
   <p>
       
   @author Chris Anderson 
   @version 01/22/09
*/ 
//
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// Chris Anderson (C) UCLA                             Jan. 22, 2009
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//
#include "VectorFunction.h"
#include "DoubleVector.h"

#ifndef __RKF45method__
#define __RKF45method__

class RKF45method
{

public : 

    RKF45method();

    /// Sets the relative and absolute error tolerance of the solution value after one step of size dt
    
    void   setErrorTolerance(double tol);
    
    /// Returns the current error tolerance 
    
    double getErrorTolerance() const;
 
    /// Returns the error code associated with the RK 45 procedure 
    
    int    getErrorCode() const;
    
    /// The value of yk is updated with the solution of the ODE starting from yk and advancing one timestep dt.
    
    int  advance(DoubleVector& yk, double dt, VectorFunction* fPtr);
    
protected :


    double errorTolerance;
    int         errorCode;

};
#endif

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