G4ImportanceAlgorithm Class Reference

#include <G4ImportanceAlgorithm.hh>

Inheritance diagram for G4ImportanceAlgorithm:

Collaboration diagram for G4ImportanceAlgorithm:

Public Member Functions
	G4ImportanceAlgorithm ()
virtual	~G4ImportanceAlgorithm ()
virtual G4Nsplit_Weight	Calculate (G4double ipre, G4double ipost, G4double init_w) const
Public Member Functions inherited from G4VImportanceAlgorithm
	G4VImportanceAlgorithm ()
virtual	~G4VImportanceAlgorithm ()

Detailed Description

Definition at line 44 of file G4ImportanceAlgorithm.hh.

Constructor & Destructor Documentation

G4ImportanceAlgorithm::G4ImportanceAlgorithm

(

)

Definition at line 47 of file G4ImportanceAlgorithm.cc.

                                            : fWorned(false)
{
}

G4ImportanceAlgorithm::~G4ImportanceAlgorithm ( )

virtual

Definition at line 51 of file G4ImportanceAlgorithm.cc.

{
}

Member Function Documentation

G4Nsplit_Weight G4ImportanceAlgorithm::Calculate ( G4double  ipre, G4double  ipost, G4double  init_w  ) const

virtual

Implements G4VImportanceAlgorithm.

Definition at line 56 of file G4ImportanceAlgorithm.cc.

{

#ifdef G4MULTITHREADED
  G4MUTEXLOCK(&G4ImportanceAlgorithm::ImportanceMutex);
#endif

  G4Nsplit_Weight nw = {0,0};
  if (ipost>0.){
    if (!(ipre>0.)){
      Error("Calculate() - ipre==0.");
    }
    G4double ipre_over_ipost = ipre/ipost;
    if ((ipre_over_ipost<0.25 || ipre_over_ipost> 4) && !fWorned) {
      std::ostringstream os;
      os << "Calculate() - ipre_over_ipost ! in [0.25, 4]." << G4endl
         << "ipre_over_ipost = " << ipre_over_ipost << ".";
      Warning(os.str());
      fWorned = true;
      if (ipre_over_ipost<=0) {
    Error("Calculate() - ipre_over_ipost<=0.");
      }
    }
    if (init_w<=0.) {
      Error("Calculate() - iniitweight<= 0. found!");
    }

    // default geometrical splitting 
    // in integer mode 
    // for ipre_over_ipost <= 1
    G4double inv = 1./ipre_over_ipost;
    nw.fN = static_cast<G4int>(inv);
    nw.fW = init_w * ipre_over_ipost;
    
    // geometrical splitting for double mode
    if (ipre_over_ipost<1) {
      if ( static_cast<G4double>(nw.fN) != inv) {
    // double mode
    // probability p for splitting into n+1 tracks
    G4double p = inv - nw.fN;
    // get a random number out of [0,1)
    G4double r = G4UniformRand();
    if (r<p) {
      nw.fN++;
    } 
      }  
    }
    // ipre_over_ipost > 1
    //  russian roulett
    else if (ipre_over_ipost>1) {
      // probabiity for killing track
      G4double p = 1-inv;
      // get a random number out of [0,1)
      G4double r = G4UniformRand();
      if (r<p) {
    // kill track
    nw.fN = 0;
    nw.fW = 0;
      }
      else {
    nw.fN = 1;     
      }
    }
  }
#ifdef G4MULTITHREADED
  G4MUTEXUNLOCK(&G4ImportanceAlgorithm::ImportanceMutex);
#endif
  return nw;
}

---

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

• source/geant4.10.03.p02/source/geometry/biasing/include/G4ImportanceAlgorithm.hh
• source/geant4.10.03.p02/source/geometry/biasing/src/G4ImportanceAlgorithm.cc