#include <EvtItgSimpsonIntegrator.hh>

Inheritance diagram for EvtItgSimpsonIntegrator:

Public Member Functions
	EvtItgSimpsonIntegrator (const EvtItgAbsFunction &, double precision=1.0e-5, int maxLoop=20)

virtual	~EvtItgSimpsonIntegrator ()

Public Member Functions inherited from EvtItgAbsIntegrator
	EvtItgAbsIntegrator (const EvtItgAbsFunction &)

virtual	~EvtItgAbsIntegrator ()

double	evaluate (double lower, double upper) const

double	normalisation () const

Protected Member Functions
virtual double	evaluateIt (double, double) const

Protected Member Functions inherited from EvtItgAbsIntegrator
double	trapezoid (double lower, double higher, int n, double &result) const

virtual double	evaluateIt (double lower, double higher) const =0

double	myFunction (double x) const

Detailed Description

Definition at line 35 of file EvtItgSimpsonIntegrator.hh.

Constructor & Destructor Documentation

◆ EvtItgSimpsonIntegrator()

EvtItgSimpsonIntegrator::EvtItgSimpsonIntegrator	(	const EvtItgAbsFunction &	theFunction,
		double	precision = `1.0e-5`,
		int	maxLoop = `20`
	)

Definition at line 49 of file EvtItgSimpsonIntegrator.cc.

                                                                                                                   :
  EvtItgAbsIntegrator(theFunction),
  _precision(precision),
  _maxLoop(maxLoop)
{}

Referenced by EvtItgSimpsonIntegrator().

◆ ~EvtItgSimpsonIntegrator()

EvtItgSimpsonIntegrator::~EvtItgSimpsonIntegrator ( )

virtual

Definition at line 60 of file EvtItgSimpsonIntegrator.cc.

61{}

Member Function Documentation

◆ evaluateIt()

double EvtItgSimpsonIntegrator::evaluateIt	(	double	lower,
		double	higher
	)		const

protectedvirtual

Implements EvtItgAbsIntegrator.

Definition at line 64 of file EvtItgSimpsonIntegrator.cc.

                                                                    {
  
  // report(INFO,"EvtGen")<<"in evaluate"<<endl;
  int j;
  double result(0.0);
  double s, st, ost(0.0);
  for (j=1;j<4;j++) {
    st = trapezoid(lower, higher, j, result);
    s = (4.0 * st - ost)/3.0;
    ost=st;
  }
 
  double olds(s);
  st = trapezoid(lower, higher, j, result);
  s = (4.0 * st - ost)/3.0;
 
  if (fabs(s - olds) < _precision*fabs(olds) || (s==0.0 && olds==0.0))     return s;
  
  ost=st;
 
  for (j=5;j<_maxLoop;j++){
 
    st = trapezoid(lower, higher, j, result);
    s = (4.0 * st - ost)/3.0;
    
    if (fabs(s - olds) < _precision*fabs(olds) || (s==0.0 && olds==0.0))    return s;
    olds=s;
    ost=st;
  }
  
  report(ERROR,"EvtGen") << "Severe error in EvtItgSimpsonIntegrator.  Failed to converge after loop with 2**"
         << _maxLoop << " calls to the integrand in." << endl;
  
  return 0.0;
    
}

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