A simple GENIE flux driver for neutrinos following a power law spectrum. Can handle a mix of neutrinos with their corresponding weight. More...

#include <GPowerLawFlux.h>

Inheritance diagram for genie::flux::GPowerLawFlux:

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Collaboration diagram for genie::flux::GPowerLawFlux:

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Public Member Functions
	GPowerLawFlux ()
	GPowerLawFlux (double alpha, double emin, double emax, int pdg)
	GPowerLawFlux (double alpha, double emin, double emax, const map< int, double > &numap)
	~GPowerLawFlux ()
const PDGCodeList &	FluxParticles (void)
	declare list of flux neutrinos that can be generated (for init. purposes)
double	MaxEnergy (void)
	declare the max flux neutrino energy that can be generated (for init. purposes)
bool	GenerateNext (void)
	generate the next flux neutrino (return false in err)
int	PdgCode (void)
	returns the flux neutrino pdg code
double	Weight (void)
	returns the flux neutrino weight (if any)
const TLorentzVector &	Momentum (void)
	returns the flux neutrino 4-momentum
const TLorentzVector &	Position (void)
	returns the flux neutrino 4-position (note: expect SI rather than physical units)
bool	End (void)
	true if no more flux nu's can be thrown (eg reaching end of beam sim ntuples)
long int	Index (void)
	returns corresponding index for current flux neutrino (e.g. for a flux ntuple returns the current entry number)
void	Clear (Option_t *opt)
	reset state variables based on opt
void	GenerateWeighted (bool gen_weighted)
	set whether to generate weighted or unweighted neutrinos
void	SetDirectionCos (double dx, double dy, double dz)
void	SetRayOrigin (double x, double y, double z)
void	SetNuDirection (const TVector3 &direction)
void	SetBeamSpot (const TVector3 &spot)
void	Initialize (double alpha, double emin, double emax, int pdg)
void	Initialize (double alpha, double emin, double emax, const map< int, double > &numap)
Public Member Functions inherited from genie::GFluxI
virtual	~GFluxI ()

Private Member Functions
void	CleanUp (void)

Private Attributes
double	fSpectralIndex
	spectral index (E^{-alpha})
double	fMinEv
	minimum energy
double	fMaxEv
	maximum energy
PDGCodeList *	fPdgCList
	list of neutrino pdg-codes
int	fgPdgC
	running generated nu pdg-code
TLorentzVector	fgP4
	running generated nu 4-momentum
TLorentzVector	fgX4
	running generated nu 4-position
map< int, double >	fProb
	cumulative probability of neutrino types
double	fProbMax

Additional Inherited Members
Protected Member Functions inherited from genie::GFluxI
	GFluxI ()

Detailed Description

A simple GENIE flux driver for neutrinos following a power law spectrum. Can handle a mix of neutrinos with their corresponding weight.

Author: Alfonso Garcia <aagarciasoto \at km3net.de> IFIC

Created:\n May 02, 2023

License:\n Copyright (c) 2003-2025, The GENIE Collaboration: For the full text of the license visit http://copyright.genie-mc.org

Definition at line 36 of file GPowerLawFlux.h.

Constructor & Destructor Documentation

◆ GPowerLawFlux() [1/3]

GPowerLawFlux::GPowerLawFlux ( )

Definition at line 28 of file GPowerLawFlux.cxx.

                             :
GFluxI()
{
  // default ctor for consistency with GFluxDriverFactory needs
  // up to user to call Initialize() to set energy and flavor(s)
}

References genie::GFluxI::GFluxI().

◆ GPowerLawFlux() [2/3]

GPowerLawFlux::GPowerLawFlux	(	double	alpha,
		double	emin,
		double	emax,
		int	pdg )

Definition at line 35 of file GPowerLawFlux.cxx.

                                                                            :
GFluxI()
{
  this->Initialize(alpha,emin,emax,pdg);
}

References genie::GFluxI::GFluxI(), and Initialize().

◆ GPowerLawFlux() [3/3]

GPowerLawFlux::GPowerLawFlux	(	double	alpha,
		double	emin,
		double	emax,
		const map< int, double > &	numap )

Definition at line 41 of file GPowerLawFlux.cxx.

                                                                              :
GFluxI()
{
  this->Initialize(alpha,emin,emax,numap);
}

References genie::GFluxI::GFluxI(), and Initialize().

◆ ~GPowerLawFlux()

GPowerLawFlux::~GPowerLawFlux ( )

Definition at line 48 of file GPowerLawFlux.cxx.

{
  this->CleanUp();
}

References CleanUp().

Member Function Documentation

◆ CleanUp()

void GPowerLawFlux::CleanUp ( void )

private

Definition at line 144 of file GPowerLawFlux.cxx.

{
  LOG("Flux", pNOTICE) << "Cleaning up...";
 
  if (fPdgCList) delete fPdgCList;
}

References fPdgCList, LOG, and pNOTICE.

Referenced by ~GPowerLawFlux().

◆ Clear()

void GPowerLawFlux::Clear ( Option_t * opt )

virtual

reset state variables based on opt

Implements genie::GFluxI.

Definition at line 87 of file GPowerLawFlux.cxx.

{
// Dummy clear method needed to conform to GFluxI interface
//
  LOG("Flux", pERROR) <<
      "No Clear(Option_t * opt) method implemented for opt: "<< opt;
}

References LOG, and pERROR.

◆ End()

bool genie::flux::GPowerLawFlux::End ( void )

inlinevirtual

true if no more flux nu's can be thrown (eg reaching end of beam sim ntuples)

Implements genie::GFluxI.

Definition at line 52 of file GPowerLawFlux.h.

52{ return false; }

◆ FluxParticles()

const PDGCodeList & genie::flux::GPowerLawFlux::FluxParticles ( void )

inlinevirtual

declare list of flux neutrinos that can be generated (for init. purposes)

Implements genie::GFluxI.

Definition at line 45 of file GPowerLawFlux.h.

45{ return *fPdgCList; }

References fPdgCList.

◆ GenerateNext()

bool GPowerLawFlux::GenerateNext ( void )

virtual

generate the next flux neutrino (return false in err)

Implements genie::GFluxI.

Definition at line 53 of file GPowerLawFlux.cxx.

{
  RandomGen * rnd = RandomGen::Instance();
  double p = fProbMax * rnd->RndFlux().Rndm();
 
  map<int,double>::const_iterator iter;
  for(iter = fProb.begin(); iter != fProb.end(); ++iter) {
     int    nupdgc = iter->first;
     double prob   = iter->second;
     if (p<prob) {
       fgPdgC = nupdgc;
       break;
     }
  }
 
  double Ev = 0.;
  if (fSpectralIndex==1) Ev = TMath::Exp(TMath::Log(fMinEv)+rnd->RndFlux().Rndm()*TMath::Log(fMaxEv/fMinEv));
  else {
    double pemin = TMath::Power(fMinEv,  1.-fSpectralIndex);
    double pemax = TMath::Power(fMaxEv,  1.-fSpectralIndex);
    Ev = TMath::Power(pemin+(pemax-pemin)*rnd->RndFlux().Rndm(),1./(1.-fSpectralIndex));
  }
 
  fgP4.SetPxPyPzE (0.,0.,Ev,Ev);
 
  LOG("Flux", pINFO)
        << "Generated neutrino: "
        << "\n pdg-code: " << fgPdgC
        << "\n p4: " << utils::print::P4AsShortString(&fgP4)
        << "\n x4: " << utils::print::X4AsString(&fgX4);
 
  return true;
}

References fgP4, fgPdgC, fgX4, fMaxEv, fMinEv, fProb, fProbMax, fSpectralIndex, genie::RandomGen::Instance(), LOG, genie::utils::print::P4AsShortString(), pINFO, genie::RandomGen::RndFlux(), and genie::utils::print::X4AsString().

◆ GenerateWeighted()

void GPowerLawFlux::GenerateWeighted ( bool gen_weighted )

virtual

set whether to generate weighted or unweighted neutrinos

Implements genie::GFluxI.

Definition at line 95 of file GPowerLawFlux.cxx.

{
// Dummy implementation needed to conform to GFluxI interface
//
  LOG("Flux", pERROR) <<
      "No GenerateWeighted(bool gen_weighted) method implemented for " <<
      "gen_weighted: " << gen_weighted;
}

References LOG, and pERROR.

◆ Index()

long int genie::flux::GPowerLawFlux::Index ( void )

inlinevirtual

returns corresponding index for current flux neutrino (e.g. for a flux ntuple returns the current entry number)

Implements genie::GFluxI.

Definition at line 53 of file GPowerLawFlux.h.

53{ return -1; }

◆ Initialize() [1/2]

void GPowerLawFlux::Initialize	(	double	alpha,
		double	emin,
		double	emax,
		const map< int, double > &	numap )

Definition at line 112 of file GPowerLawFlux.cxx.

{
  LOG("Flux", pNOTICE) << "Initializing GPowerLawFlux driver";
 
  fSpectralIndex = alpha;
  fMinEv         = emin;
  fMaxEv         = emax;
 
  LOG("Flux", pNOTICE) << "Spectral Index : " << fSpectralIndex;
  LOG("Flux", pNOTICE) << "Energy range : " << fMinEv << " , " << fMaxEv;
 
  fPdgCList = new PDGCodeList;
  fPdgCList->clear();
 
  fProbMax = 0;
  fProb.clear();
 
  map<int,double>::const_iterator iter;
  for(iter = numap.begin(); iter != numap.end(); ++iter) {
        int    nupdgc = iter->first;
        double nuwgt  = iter->second;
 
        fPdgCList->push_back(nupdgc);
 
        fProbMax+=nuwgt;
        fProb.insert(map<int, double>::value_type(nupdgc,fProbMax));
  }
 
  fgPdgC = 0;
  fgX4.SetXYZT (0.,0.,0.,0.);
}

References fgPdgC, fgX4, fMaxEv, fMinEv, fPdgCList, fProb, fProbMax, fSpectralIndex, LOG, and pNOTICE.

◆ Initialize() [2/2]

void GPowerLawFlux::Initialize	(	double	alpha,
		double	emin,
		double	emax,
		int	pdg )

Definition at line 104 of file GPowerLawFlux.cxx.

{
  map<int,double> numap;
  numap.insert( map<int, double>::value_type(pdg, 1.) );
 
  this->Initialize(alpha,emin,emax,numap);
}

References Initialize().

◆ MaxEnergy()

double genie::flux::GPowerLawFlux::MaxEnergy ( void )

inlinevirtual

declare the max flux neutrino energy that can be generated (for init. purposes)

Implements genie::GFluxI.

Definition at line 46 of file GPowerLawFlux.h.

46{ return fMaxEv; }

References fMaxEv.

◆ Momentum()

const TLorentzVector & genie::flux::GPowerLawFlux::Momentum ( void )

inlinevirtual

returns the flux neutrino 4-momentum

Implements genie::GFluxI.

Definition at line 50 of file GPowerLawFlux.h.

50{ return fgP4; }

References fgP4.

◆ PdgCode()

int genie::flux::GPowerLawFlux::PdgCode ( void )

inlinevirtual

returns the flux neutrino pdg code

Implements genie::GFluxI.

Definition at line 48 of file GPowerLawFlux.h.

48{ return fgPdgC; }

References fgPdgC.

◆ Position()

const TLorentzVector & genie::flux::GPowerLawFlux::Position ( void )

inlinevirtual

returns the flux neutrino 4-position (note: expect SI rather than physical units)

Implements genie::GFluxI.

Definition at line 51 of file GPowerLawFlux.h.

51{ return fgX4; }

References fgX4.

◆ SetBeamSpot()

void GPowerLawFlux::SetBeamSpot ( const TVector3 & spot )

Definition at line 174 of file GPowerLawFlux.cxx.

{
  SetRayOrigin(spot.x(), spot.y(), spot.z());
}

References SetRayOrigin().

◆ SetDirectionCos()

void GPowerLawFlux::SetDirectionCos	(	double	dx,
		double	dy,
		double	dz )

Definition at line 151 of file GPowerLawFlux.cxx.

{
  TVector3 dircos1 = TVector3(dx,dy,dz).Unit();
  LOG("Flux", pNOTICE) << "SetDirectionCos "
                       << utils::print::P3AsString(&dircos1);
  double E = fgP4.E();
  fgP4.SetVect(E*dircos1);
 
}

References fgP4, LOG, genie::utils::print::P3AsString(), and pNOTICE.

Referenced by SetNuDirection().

◆ SetNuDirection()

void GPowerLawFlux::SetNuDirection ( const TVector3 & direction )

Definition at line 169 of file GPowerLawFlux.cxx.

{
  SetDirectionCos(direction.x(), direction.y(), direction.z());
}

References SetDirectionCos().

◆ SetRayOrigin()

void GPowerLawFlux::SetRayOrigin	(	double	x,
		double	y,
		double	z )

Definition at line 161 of file GPowerLawFlux.cxx.

{
  TVector3 xyz(x,y,z);
  LOG("Flux", pNOTICE) << "SetRayOrigin "
                       << utils::print::Vec3AsString(&xyz);
  fgX4.SetVect(xyz);
}

References fgX4, LOG, pNOTICE, and genie::utils::print::Vec3AsString().

Referenced by SetBeamSpot().

◆ Weight()

double genie::flux::GPowerLawFlux::Weight ( void )

inlinevirtual

returns the flux neutrino weight (if any)

Implements genie::GFluxI.

Definition at line 49 of file GPowerLawFlux.h.

49{ return 1.0; }

Member Data Documentation

◆ fgP4

TLorentzVector genie::flux::GPowerLawFlux::fgP4

private

running generated nu 4-momentum

Definition at line 79 of file GPowerLawFlux.h.

Referenced by GenerateNext(), Momentum(), and SetDirectionCos().

◆ fgPdgC

int genie::flux::GPowerLawFlux::fgPdgC

private

running generated nu pdg-code

Definition at line 78 of file GPowerLawFlux.h.

Referenced by GenerateNext(), Initialize(), and PdgCode().

◆ fgX4

TLorentzVector genie::flux::GPowerLawFlux::fgX4

private

running generated nu 4-position

Definition at line 80 of file GPowerLawFlux.h.

Referenced by GenerateNext(), Initialize(), Position(), and SetRayOrigin().

◆ fMaxEv

double genie::flux::GPowerLawFlux::fMaxEv

private

maximum energy

Definition at line 76 of file GPowerLawFlux.h.

Referenced by GenerateNext(), Initialize(), and MaxEnergy().

◆ fMinEv

double genie::flux::GPowerLawFlux::fMinEv

private

minimum energy

Definition at line 75 of file GPowerLawFlux.h.

Referenced by GenerateNext(), and Initialize().

◆ fPdgCList

PDGCodeList* genie::flux::GPowerLawFlux::fPdgCList

private

list of neutrino pdg-codes

Definition at line 77 of file GPowerLawFlux.h.

Referenced by CleanUp(), FluxParticles(), and Initialize().

◆ fProb

map<int, double> genie::flux::GPowerLawFlux::fProb

private

cumulative probability of neutrino types

Definition at line 81 of file GPowerLawFlux.h.

Referenced by GenerateNext(), and Initialize().

◆ fProbMax

double genie::flux::GPowerLawFlux::fProbMax

private

Definition at line 82 of file GPowerLawFlux.h.

Referenced by GenerateNext(), and Initialize().

◆ fSpectralIndex

double genie::flux::GPowerLawFlux::fSpectralIndex

private

spectral index (E^{-alpha})

Definition at line 74 of file GPowerLawFlux.h.

Referenced by GenerateNext(), and Initialize().

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

Public Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ GPowerLawFlux() [1/3]

◆ GPowerLawFlux() [2/3]

◆ GPowerLawFlux() [3/3]

◆ ~GPowerLawFlux()

Member Function Documentation

◆ CleanUp()

◆ Clear()

◆ End()

◆ FluxParticles()

◆ GenerateNext()

◆ GenerateWeighted()

◆ Index()

◆ Initialize() [1/2]

◆ Initialize() [2/2]

◆ MaxEnergy()

◆ Momentum()

◆ PdgCode()

◆ Position()

◆ SetBeamSpot()

◆ SetDirectionCos()

◆ SetNuDirection()

◆ SetRayOrigin()

◆ Weight()

Member Data Documentation

◆ fgP4

◆ fgPdgC

◆ fgX4

◆ fMaxEv

◆ fMinEv

◆ fPdgCList

◆ fProb

◆ fProbMax

◆ fSpectralIndex