Generates values for the kinematic variables describing coherent neutrino-nucleus elastic scattering events. Is a concrete implementation of the EventRecordVisitorI interface. More...

#include <COHElKinematicsGenerator.h>

Inheritance diagram for genie::COHElKinematicsGenerator:

Public Member Functions
	COHElKinematicsGenerator ()

	COHElKinematicsGenerator (string config)

	~COHElKinematicsGenerator ()

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
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 >
bool	GetParamVect (const std::string &comm_name, std::vector< T > &v, unsigned int max, 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 values for the kinematic variables describing coherent neutrino-nucleus elastic scattering events. Is a concrete implementation of the EventRecordVisitorI interface.

Author: Costas Andreopoulos <costas.andreopoulos stfc.ac.uk> University of Liverpool & STFC Rutherford Appleton Lab

November 22, 2007

Definition at line 29 of file COHElKinematicsGenerator.h.

Constructor & Destructor Documentation

COHElKinematicsGenerator::COHElKinematicsGenerator ( )

Definition at line 42 of file COHElKinematicsGenerator.cxx.

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

COHElKinematicsGenerator::COHElKinematicsGenerator ( string config )

Definition at line 48 of file COHElKinematicsGenerator.cxx.

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

COHElKinematicsGenerator::~COHElKinematicsGenerator ( )

Definition at line 54 of file COHElKinematicsGenerator.cxx.

 {
 
 }

Member Function Documentation

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

virtual

Implements genie::KineGeneratorWithCache.

Definition at line 172 of file COHElKinematicsGenerator.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.
 
   SLOG("COHElKinematics", pDEBUG)
           << "Scanning the allowed phase space {K} for the max(dxsec/d{K})";
 
   double max_xsec = 0.;
   const int N     = 50;
 
   const KPhaseSpace & kps = in->PhaseSpace();
   Range1D_t yr = kps.YLim();
 
   const double logymin = TMath::Log10(yr.min);
   const double logymax = TMath::Log10(yr.max);
   const double dlogy   = (logymax - logymin) /(N-1);
 
   for(int i=0; i<N; i++) {
      double y = TMath::Power(10, logymin+i*dlogy);
      in->KinePtr()->Sety(y);
 
      double xsec = fXSecModel->XSec(in, kPSyfE);
      LOG("COHElKinematics", pDEBUG)  << "xsec(y= " << y << ") = " << xsec;
      max_xsec = TMath::Max(max_xsec, xsec);
   }//y
 
   // Apply safety factor, since value retrieved from the cache might
   // correspond to a slightly different energy.
   max_xsec *= fSafetyFactor;
 
   SLOG("COHElKinematics", pDEBUG) << in->AsString();
   SLOG("COHElKinematics", pDEBUG) << "Max xsec in phase space = " << max_xsec;
   SLOG("COHElKinematics", pDEBUG) << "Computed using alg = " << fXSecModel->Id();
 
   return max_xsec;
 }

void COHElKinematicsGenerator::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 222 of file COHElKinematicsGenerator.cxx.

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

void COHElKinematicsGenerator::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 228 of file COHElKinematicsGenerator.cxx.

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

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

virtual

Reimplemented from genie::KineGeneratorWithCache.

Definition at line 212 of file COHElKinematicsGenerator.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 COHElKinematicsGenerator::LoadConfig ( void )

Definition at line 234 of file COHElKinematicsGenerator.cxx.

 {
   //-- max xsec safety factor (for rejection method) and min cached energy
   GetParamDef( "MaxXSec-SafetyFactor", fSafetyFactor, 1.6 ) ;
   GetParamDef( "Cache-MinEnergy", fEMin, -1.0 ) ;
 
   //-- Generate kinematics uniformly over allowed phase space and compute
   //   an event weight?
   GetParamDef( "UniformOverPhaseSpace", fGenerateUniformly, false ) ;
 
   //-- Maximum allowed fractional cross section deviation from maxim cross
   //   section used in rejection method
   GetParamDef( "MaxXSec-DiffTolerance", fMaxXSecDiffTolerance, 999999. ) ;
   assert(fMaxXSecDiffTolerance>=0);
 }

void COHElKinematicsGenerator::ProcessEventRecord ( GHepRecord * event_rec ) const

virtual

Implements genie::EventRecordVisitorI.

Definition at line 59 of file COHElKinematicsGenerator.cxx.

 {
   if(fGenerateUniformly) {
     LOG("COHElKinematics", pNOTICE)
        << "Generating kinematics uniformly over the allowed phase space";
   }
 
   Interaction * interaction = evrec->Summary();
   interaction->SetBit(kISkipProcessChk);
   interaction->SetBit(kISkipKinematicChk);
 
   //-- 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);
 
   //-- Get the kinematical limits for the generated x,y
   const KPhaseSpace & kps = interaction->PhaseSpace();
   Range1D_t y = kps.YLim();
   assert(y.min>0. && y.max>0. && y.min<1. && y.max<1. && y.min<y.max);
   const double ymin = y.min + kASmallNum;
   const double ymax = y.max - kASmallNum;
   const double dy   = ymax - ymin;
 
   //------ Try to select a valid y
   unsigned int iter = 0;
   bool accept=false;
   double xsec=-1, gy=-1;
 
   while(1) {
      iter++;
      if(iter > kRjMaxIterations) {
         LOG("COHElKinematics", 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;
      }
 
      gy = ymin + dy * rnd->RndKine().Rndm();
      LOG("COHElKinematics", pINFO) << "Trying: y = " << gy;
 
      interaction->KinePtr()->Sety(gy);
 
      // computing cross section for the current kinematics
      xsec = fXSecModel->XSec(interaction, kPSyfE);
 
      //-- decide whether to accept the current kinematics
      if(!fGenerateUniformly) {
         double t = xsec_max * rnd->RndKine().Rndm();
         this->AssertXSecLimits(interaction, xsec, xsec_max);
         LOG("COHElKinematics", pINFO) << "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("COHElKinematics", pNOTICE) << "Selected: y = " << gy;
 
         // for uniform kinematics, compute an event weight as
         // wght = (phase space volume)*(differential xsec)/(event total xsec)
         if(fGenerateUniformly) {
           double vol     = y.max-y.min; 
           double totxsec = evrec->XSec();
           double wght    = (vol/totxsec)*xsec;
           LOG("COHElKinematics", pNOTICE)  << "Kinematics wght = "<< wght;
 
           // apply computed weight to the current event weight
           wght *= evrec->Weight();
           LOG("COHElKinematics", pNOTICE) << "Current event wght = " << wght;
           evrec->SetWeight(wght);
         }
 
         // reset bits
         interaction->ResetBit(kISkipProcessChk);
         interaction->ResetBit(kISkipKinematicChk);
 
         // lock selected kinematics & clear running values
         double Ev = interaction->InitState().ProbeE(kRfLab);
         double x  = 1;
         double Q2 = 2*kNucleonMass*x*gy*Ev;
         interaction->KinePtr()->Setx(x,   true);
         interaction->KinePtr()->Sety(gy,  true);
         interaction->KinePtr()->Sett(0,   true);
         interaction->KinePtr()->SetW(0,   true);
         interaction->KinePtr()->SetQ2(Q2, true);
         interaction->KinePtr()->ClearRunningValues();
 
         // set the cross section for the selected kinematics
         // TODO: this is kPSxyfE on the dev branch, but I think kPSyfE is right
         evrec->SetDiffXSec(xsec,kPSyfE);
 
         return;
      }
   }// iterations
 }

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

Generator/src/Physics/Coherent/EventGen/COHElKinematicsGenerator.h
Generator/src/Physics/Coherent/EventGen/COHElKinematicsGenerator.cxx

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation