Genfun::EmbeddedRKStepper Class Reference

#include <EmbeddedRKStepper.hh>

Inheritance diagram for Genfun::EmbeddedRKStepper:

Public Member Functions
	EmbeddedRKStepper (const ExtendedButcherTableau &tableau=CashKarpXtTableau())
virtual	~EmbeddedRKStepper ()
virtual void	step (const RKIntegrator::RKData *data, const RKIntegrator::RKData::Data &sdata, RKIntegrator::RKData::Data &ddata, std::vector< double > &errors) const
virtual EmbeddedRKStepper *	clone () const
virtual unsigned int	order () const
Public Member Functions inherited from Genfun::AdaptiveRKStepper::EEStepper
virtual	~EEStepper ()
virtual void	step (const RKIntegrator::RKData *data, const RKIntegrator::RKData::Data &sdata, RKIntegrator::RKData::Data &ddata, std::vector< double > &errors) const =0
virtual EEStepper *	clone () const =0
virtual unsigned int	order () const =0

Detailed Description

Definition at line 11 of file EmbeddedRKStepper.hh.

Constructor & Destructor Documentation

EmbeddedRKStepper()

Genfun::EmbeddedRKStepper::EmbeddedRKStepper

(

const ExtendedButcherTableau &

tableau = CashKarpXtTableau()

)

Definition at line 9 of file EmbeddedRKStepper.cc.

                                                                             :
    tableau(mtableau){
  }

~EmbeddedRKStepper()

Genfun::EmbeddedRKStepper::~EmbeddedRKStepper ( )

virtual

Definition at line 13 of file EmbeddedRKStepper.cc.

                                        {
  }

Member Function Documentation

clone()

EmbeddedRKStepper * Genfun::EmbeddedRKStepper::clone ( ) const

virtual

Implements Genfun::AdaptiveRKStepper::EEStepper.

Definition at line 57 of file EmbeddedRKStepper.cc.

                                                    {
    return new EmbeddedRKStepper(*this);
  }

order()

unsigned int Genfun::EmbeddedRKStepper::order ( ) const

virtual

Implements Genfun::AdaptiveRKStepper::EEStepper.

Definition at line 61 of file EmbeddedRKStepper.cc.

                                              {
    return tableau.order();
  }

step()

void Genfun::EmbeddedRKStepper::step ( const RKIntegrator::RKData *  data, const RKIntegrator::RKData::Data &  sdata, RKIntegrator::RKData::Data &  ddata, std::vector< double > &  errors  ) const

virtual

Implements Genfun::AdaptiveRKStepper::EEStepper.

Definition at line 16 of file EmbeddedRKStepper.cc.

                                                                 {
 
    // First step:
    double h = d.time - s.time;
    if (h<=0) throw std::runtime_error ("Runtime error in RKIntegrator (zero or negative stepsize)");
    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];
    // 
    // 
    //
    errors.resize(nvar);
    for (unsigned int v=0;v<nvar;v++) errors[v] = 0;
    for (unsigned int i=0;i<tableau.nSteps();i++) {
      for (unsigned int v=0;v<nvar;v++) errors[v] += (h*(tableau.bHat(i)-tableau.b(i))*k[i][v]);
    }
    return;
  }

---

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

• EmbeddedRKStepper.hh
• EmbeddedRKStepper.cc