Generates kinematics for neutrino-electron events. Is a concrete implementation of the EventRecordVisitorI interface. More...

#include <NuEKinematicsGenerator.h>

Inheritance diagram for genie::NuEKinematicsGenerator:

Public Member Functions
	NuEKinematicsGenerator ()

	NuEKinematicsGenerator (string config)

	~NuEKinematicsGenerator ()

void	ProcessEventRecord (GHepRecord *event_rec) const

void	Configure (const Registry &config)

void	Configure (string config)

void	LoadConfig (void)

double	ComputeMaxXSec (const Interaction *in) const

double	Energy (const Interaction *in) const

Public Member Functions inherited from genie::EventRecordVisitorI
virtual	~EventRecordVisitorI ()

Public Member Functions inherited from genie::Algorithm
virtual	~Algorithm ()

virtual void	FindConfig (void)

virtual const Registry &	GetConfig (void) const

Registry *	GetOwnedConfig (void)

virtual const AlgId &	Id (void) const
	Get algorithm ID. More...

virtual AlgStatus_t	GetStatus (void) const
	Get algorithm status. More...

virtual bool	AllowReconfig (void) const

virtual AlgCmp_t	Compare (const Algorithm *alg) const
	Compare with input algorithm. More...

virtual void	SetId (const AlgId &id)
	Set algorithm ID. More...

virtual void	SetId (string name, string config)

const Algorithm *	SubAlg (const RgKey &registry_key) const

void	AdoptConfig (void)

void	AdoptSubstructure (void)

virtual void	Print (ostream &stream) const
	Print algorithm info. More...

Additional Inherited Members
Static Public Member Functions inherited from genie::Algorithm
static string	BuildParamVectKey (const std::string &comm_name, unsigned int i)

static string	BuildParamVectSizeKey (const std::string &comm_name)

Protected Member Functions inherited from genie::KineGeneratorWithCache
	KineGeneratorWithCache ()

	KineGeneratorWithCache (string name)

	KineGeneratorWithCache (string name, string config)

	~KineGeneratorWithCache ()

virtual double	MaxXSec (GHepRecord *evrec) const

virtual double	FindMaxXSec (const Interaction *in) const

virtual void	CacheMaxXSec (const Interaction *in, double xsec) const

virtual CacheBranchFx *	AccessCacheBranch (const Interaction *in) const

virtual void	AssertXSecLimits (const Interaction *in, double xsec, double xsec_max) const

Protected Member Functions inherited from genie::EventRecordVisitorI
	EventRecordVisitorI ()

	EventRecordVisitorI (string name)

	EventRecordVisitorI (string name, string config)

Protected Member Functions inherited from genie::Algorithm
	Algorithm ()

	Algorithm (string name)

	Algorithm (string name, string config)

void	Initialize (void)

void	DeleteConfig (void)

void	DeleteSubstructure (void)

Registry *	ExtractLocalConfig (const Registry &in) const

Registry *	ExtractLowerConfig (const Registry &in, const string &alg_key) const
	Split an incoming configuration Registry into a block valid for the sub-algo identified by alg_key. More...

template<class T >
bool	GetParam (const RgKey &name, T &p, bool is_top_call=true) const

template<class T >
bool	GetParamDef (const RgKey &name, T &p, const T &def) const

template<class T >
int	GetParamVect (const std::string &comm_name, std::vector< T > &v, bool is_top_call=true) const
	Handle to load vectors of parameters. More...

int	GetParamVectKeys (const std::string &comm_name, std::vector< RgKey > &k, bool is_top_call=true) const

int	AddTopRegistry (Registry *rp, bool owns=true)
	add registry with top priority, also update ownership More...

int	AddLowRegistry (Registry *rp, bool owns=true)
	add registry with lowest priority, also update ownership More...

int	MergeTopRegistry (const Registry &r)

int	AddTopRegisties (const vector< Registry * > &rs, bool owns=false)
	Add registries with top priority, also udated Ownerships. More...

Protected Attributes inherited from genie::KineGeneratorWithCache
const XSecAlgorithmI *	fXSecModel

double	fSafetyFactor
	maxxsec -> maxxsec * safety_factor More...

double	fMaxXSecDiffTolerance
	max{100(xsec-maxxsec)/.5(xsec+maxxsec)} if xsec>maxxsec More...

double	fEMin
	min E for which maxxsec is cached - forcing explicit calc. More...

bool	fGenerateUniformly
	uniform over allowed phase space + event weight? More...

Protected Attributes inherited from genie::Algorithm
bool	fAllowReconfig

bool	fOwnsSubstruc
	true if it owns its substructure (sub-algs,...) More...

AlgId	fID
	algorithm name and configuration set More...

vector< Registry * >	fConfVect

vector< bool >	fOwnerships
	ownership for every registry in fConfVect More...

AlgStatus_t	fStatus
	algorithm execution status More...

AlgMap *	fOwnedSubAlgMp
	local pool for owned sub-algs (taken out of the factory pool) More...

Detailed Description

Generates kinematics for neutrino-electron events. Is a concrete implementation of the EventRecordVisitorI interface.

Author: Costas Andreopoulos <constantinos.andreopoulos cern.ch> University of Liverpool & STFC Rutherford Appleton Laboratory

July 13, 2005

Definition at line 27 of file NuEKinematicsGenerator.h.

Constructor & Destructor Documentation

NuEKinematicsGenerator::NuEKinematicsGenerator ( )

Definition at line 29 of file NuEKinematicsGenerator.cxx.

                                                :
 KineGeneratorWithCache("genie::NuEKinematicsGenerator")
 {
 
 }

NuEKinematicsGenerator::NuEKinematicsGenerator ( string config )

Definition at line 35 of file NuEKinematicsGenerator.cxx.

                                                             :
 KineGeneratorWithCache("genie::NuEKinematicsGenerator", config)
 {
 
 }

NuEKinematicsGenerator::~NuEKinematicsGenerator ( )

Definition at line 41 of file NuEKinematicsGenerator.cxx.

 {
 
 }

Member Function Documentation

double NuEKinematicsGenerator::ComputeMaxXSec ( const Interaction * in ) const

virtual

Implements genie::KineGeneratorWithCache.

Definition at line 145 of file NuEKinematicsGenerator.cxx.

 {
 // Computes the maximum differential cross section in the requested phase
 // space. This method overloads KineGeneratorWithCache::ComputeMaxXSec
 // method and the value is cached at a circular cache branch for retrieval
 // during subsequent event generation.
 // The computed max differential cross section does not need to be the exact
 // maximum. The number used in the rejection method will be scaled up by a
 // safety factor. But it needs to be fast - do not use a very small y step.
 
   const int N  = 40;
 //const int Nb =  6;
 
   const KPhaseSpace & kps = interaction->PhaseSpace();
   Range1D_t yl = kps.Limits(kKVy);
   const double ymin = yl.min;
   const double ymax = yl.max;
 
   double max_xsec = -1.0;
 
   double dy = (ymax-ymin)/(N-1);
 //double xseclast = -1;
 //bool   increasing;
 
   for(int i=0; i<N; i++) {
     double y = ymin + i * dy;
     interaction->KinePtr()->Sety(y);
     double xsec = fXSecModel->XSec(interaction, kPSyfE);
 
     SLOG("NuEKinematics", pDEBUG) << "xsec(y = " << y << ") = " << xsec;
     max_xsec = TMath::Max(xsec, max_xsec);
 /*
     increasing = xsec-xseclast>=0;
     xseclast   = xsec;
 
     // once the cross section stops increasing, I reduce the step size and
     // step backwards a little bit to handle cases that the max cross section
     // is grossly underestimated (very peaky distribution & large step)
     if(!increasing) {
        dy/=(Nb+1);
        for(int ib=0; ib<Nb; ib++) {
          y = y-dy;
          if(y<ymin) break;
          interaction->KinePtr()->Sety(y);
          xsec = fXSecModel->XSec(interaction, kPSyfE);
          SLOG("NuEKinematics", pDEBUG) << "xsec(y = " << y << ") = " << xsec;
          max_xsec = TMath::Max(xsec, max_xsec);
        }
        break;
     }
 */
   }//y
 
   // Apply safety factor, since value retrieved from the cache might
   // correspond to a slightly different energy.
   max_xsec *= fSafetyFactor;
 
   SLOG("NuEKinematics", pDEBUG) << interaction->AsString();
   SLOG("NuEKinematics", pDEBUG) << "Max xsec in phase space = " << max_xsec;
   SLOG("NuEKinematics", pDEBUG) << "Computed using alg = " << *fXSecModel;
 
   return max_xsec;
 }

void NuEKinematicsGenerator::Configure ( const Registry & config )

virtual

Configure the algorithm with an external registry The registry is merged with the top level registry if it is owned, Otherwise a copy of it is added with the highest priority

Reimplemented from genie::Algorithm.

Definition at line 220 of file NuEKinematicsGenerator.cxx.

 {
   Algorithm::Configure(config);
   this->LoadConfig();
 }

void NuEKinematicsGenerator::Configure ( string config )

virtual

Configure the algorithm from the AlgoConfigPool based on param_set string given in input An algorithm contains a vector of registries coming from different xml configuration files, which are loaded according a very precise prioriy This methods will load a number registries in order of priority: 1) "Tunable" parameter set from CommonParametes. This is loaded with the highest prioriry and it is designed to be used for tuning procedure Usage not expected from the user. 2) For every string defined in "CommonParame" the corresponding parameter set will be loaded from CommonParameter.xml 3) parameter set specified by the config string and defined in the xml file of the algorithm 4) if config is not "Default" also the Default parameter set from the same xml file will be loaded Effectively this avoids the repetion of a parameter when it is not changed in the requested configuration

Reimplemented from genie::Algorithm.

Definition at line 226 of file NuEKinematicsGenerator.cxx.

 {
   Algorithm::Configure(config);
   this->LoadConfig();
 }

double NuEKinematicsGenerator::Energy ( const Interaction * in ) const

virtual

Reimplemented from genie::KineGeneratorWithCache.

Definition at line 210 of file NuEKinematicsGenerator.cxx.

 {
 // Override the base class Energy() method to cache the max xsec for the
 // neutrino energy in the LAB rather than in the hit nucleon rest frame.
 
   const InitialState & init_state = interaction->InitState();
   double E = init_state.ProbeE(kRfLab);
   return E;
 }

void NuEKinematicsGenerator::LoadConfig ( void )

Definition at line 232 of file NuEKinematicsGenerator.cxx.

 {
         GetParamDef( "MaxXSec-SafetyFactor", fSafetyFactor, 2.00 ) ;
         GetParamDef( "Cache-MinEnergy", fEMin, 1.00 ) ;
 
         GetParamDef("MaxXSec-DiffTolerance", fMaxXSecDiffTolerance, 0. ) ;
         assert(fMaxXSecDiffTolerance>=0);
 
   //-- Generate kinematics uniformly over allowed phase space and compute
   //   an event weight?
         GetParamDef( "UniformOverPhaseSpace", fGenerateUniformly, false ) ;
 
 }

void NuEKinematicsGenerator::ProcessEventRecord ( GHepRecord * event_rec ) const

virtual

Implements genie::EventRecordVisitorI.

Definition at line 46 of file NuEKinematicsGenerator.cxx.

 {
   if(fGenerateUniformly) {
     LOG("NuEKinematics", pNOTICE)
           << "Generating kinematics uniformly over the allowed phase space";
   }
 
   //-- Get the random number generators
   RandomGen * rnd = RandomGen::Instance();
 
   //-- Access cross section algorithm for running thread
   RunningThreadInfo * rtinfo = RunningThreadInfo::Instance();
   const EventGeneratorI * evg = rtinfo->RunningThread();
   fXSecModel = evg->CrossSectionAlg();
 
   //-- For the subsequent kinematic selection with the rejection method:
   //   Calculate the max differential cross section or retrieve it from the
   //   cache. Throw an exception and quit the evg thread if a non-positive
   //   value is found.
   //   If the kinematics are generated uniformly over the allowed phase
   //   space the max xsec is irrelevant
   double xsec_max = (fGenerateUniformly) ? -1 : this->MaxXSec(evrec);
 
   //-- y range
   const KPhaseSpace & kps = evrec->Summary()->PhaseSpace();
   Range1D_t yl = kps.Limits(kKVy);
   double ymin = yl.min;
   double ymax = yl.max;
   double dy   = ymax-ymin;
 
   double xsec = -1;
   Interaction * interaction = evrec->Summary();
 
   //-- Try to select a valid inelastisity y
   unsigned int iter = 0;
   bool accept = false;
   while(1) {
      iter++;
      if(iter > kRjMaxIterations) {
         LOG("NuEKinematics", pWARN)
               << "*** Could not select a valid y after "
                                               << iter << " iterations";
         evrec->EventFlags()->SetBitNumber(kKineGenErr, true);
         genie::exceptions::EVGThreadException exception;
         exception.SetReason("Couldn't select kinematics");
         exception.SwitchOnFastForward();
         throw exception;
      }
 
      double y = ymin + dy * rnd->RndKine().Rndm();
      interaction->KinePtr()->Sety(y);
 
      LOG("NuEKinematics", pINFO) << "Trying: y = " << y;
 
      //-- computing cross section for the current kinematics
      xsec = fXSecModel->XSec(interaction, kPSyfE);
 
      //-- decide whether to accept the current kinematics
      if(!fGenerateUniformly) {
         this->AssertXSecLimits(interaction, xsec, xsec_max);
 
         double t = xsec_max * rnd->RndKine().Rndm();
         LOG("NuEKinematics", pDEBUG) << "xsec= "<< xsec<< ", J= 1, Rnd= "<< t;
 
         accept = (t<xsec);
      } else {
        accept = (xsec>0);
      }
 
      //-- If the generated kinematics are accepted, finish-up module's job
      if(accept) {
         LOG("NuEKinematics", pINFO) << "Selected: y = " << y;
 
         // set the cross section for the selected kinematics
         evrec->SetDiffXSec(xsec,kPSyfE);
 
         // for uniform kinematics, compute an event weight as
         // wght = (phase space volume)*(differential xsec)/(event total xsec)
          if(fGenerateUniformly) {
            double vol     = kinematics::PhaseSpaceVolume(interaction,kPSyfE);
            double totxsec = evrec->XSec();
            double wght    = (vol/totxsec)*xsec;
            LOG("NuEKinematics", pNOTICE)  << "Kinematics wght = "<< wght;
 
            // apply computed weight to the current event weight
            wght *= evrec->Weight();
            LOG("NuEKinematics", pNOTICE) << "Current event wght = " << wght;
            evrec->SetWeight(wght);
         }
 
         // lock selected kinematics & clear running values
         interaction->KinePtr()->Sety(y, true);
         interaction->KinePtr()->ClearRunningValues();
 
         return;
      }
   }// iterations
 }

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

Generator/src/Physics/NuElectron/EventGen/NuEKinematicsGenerator.h
Generator/src/Physics/NuElectron/EventGen/NuEKinematicsGenerator.cxx

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation