Genfun::SimpleRKStepper Class Reference

#include <SimpleRKStepper.hh>

Inheritance diagram for Genfun::SimpleRKStepper:

Public Member Functions
	SimpleRKStepper (const ButcherTableau &tableau, double stepsize)
virtual	~SimpleRKStepper ()
virtual void	step (const RKIntegrator::RKData *data, const RKIntegrator::RKData::Data &sdata, RKIntegrator::RKData::Data &ddata, double timeLimit) const
virtual SimpleRKStepper *	clone () const
Public Member Functions inherited from Genfun::RKIntegrator::RKStepper
virtual	~RKStepper ()
virtual void	step (const RKIntegrator::RKData *data, const RKIntegrator::RKData::Data &sdata, RKIntegrator::RKData::Data &ddata, double timeLimit=0) const =0
virtual RKStepper *	clone () const =0

Detailed Description

Definition at line 17 of file SimpleRKStepper.hh.

Constructor & Destructor Documentation

SimpleRKStepper()

Genfun::SimpleRKStepper::SimpleRKStepper	(	const ButcherTableau &	tableau,
		double	stepsize
	)

Definition at line 7 of file SimpleRKStepper.cc.

                                                                                  :
    tableau(mtableau),
    stepsize(xstepsize) 
  {
  }

~SimpleRKStepper()

Genfun::SimpleRKStepper::~SimpleRKStepper ( )

virtual

Definition at line 44 of file SimpleRKStepper.cc.

{}

Member Function Documentation

clone()

SimpleRKStepper * Genfun::SimpleRKStepper::clone ( ) const

virtual

Implements Genfun::RKIntegrator::RKStepper.

Definition at line 46 of file SimpleRKStepper.cc.

                                                {
    return new SimpleRKStepper(*this);
  }

step()

void Genfun::SimpleRKStepper::step ( const RKIntegrator::RKData *  data, const RKIntegrator::RKData::Data &  sdata, RKIntegrator::RKData::Data &  ddata, double  timeLimit  ) const

virtual

Implements Genfun::RKIntegrator::RKStepper.

Definition at line 13 of file SimpleRKStepper.cc.

                                                                      {
    const double h = timeLimit==0 ? stepsize : timeLimit - s.time;
    if (h<=0) throw std::runtime_error ("SimpleRKStepper:  negative stepsize");
    const unsigned int nvar = (unsigned int)s.variable.size();
    // Compute all of the k's..:
    //
    std::vector<std::vector<double> >k(tableau.nSteps());
    for (unsigned int i=0;i<tableau.nSteps();i++) {
      k[i].resize(nvar,0);
      Argument arg(nvar);
      for (unsigned int v=0;v<nvar;v++) arg[v]=s.variable[v];
      for (unsigned int j=0;j<i;j++) {
    for (unsigned int v=0;v<nvar;v++) arg[v] += h*tableau.A(i,j)*k[j][v];
      }
      for (unsigned int v=0;v<nvar;v++) k[i][v]=(*data->_diffEqn[v])(arg);
    }
    //
    // Final result.
    //
    for (unsigned int v=0;v<nvar;v++) d.firstDerivative[v] = 0;
    for (unsigned int i=0;i<tableau.nSteps();i++) {
      for (unsigned int v=0;v<nvar;v++) d.firstDerivative[v] += tableau.b(i)*k[i][v];
    }
    for (unsigned int v=0;v<nvar;v++)   d.variable[v] =s.variable[v]+h*d.firstDerivative[v];
    d.time = timeLimit==0 ? s.time + h : timeLimit;
    
  }

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The documentation for this class was generated from the following files:

• SimpleRKStepper.hh
• SimpleRKStepper.cc