G4ImportanceAlgorithm Class Reference

#include <G4ImportanceAlgorithm.hh>

Inheritance diagram for G4ImportanceAlgorithm:

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

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Detailed Description

Definition at line 44 of file G4ImportanceAlgorithm.hh.

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Constructor & Destructor Documentation

G4ImportanceAlgorithm::G4ImportanceAlgorithm

(

)

Definition at line 42 of file G4ImportanceAlgorithm.cc.

                                            : fWorned(false)
{
}

G4ImportanceAlgorithm::~G4ImportanceAlgorithm

(

)

[virtual]

Definition at line 46 of file G4ImportanceAlgorithm.cc.

{
}

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Member Function Documentation

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

Implements G4VImportanceAlgorithm.

Definition at line 51 of file G4ImportanceAlgorithm.cc.

References G4Nsplit_Weight::fN, G4Nsplit_Weight::fW, G4endl, and G4UniformRand.

{
  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;     
      }
    }
  }
  return nw;
}

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

• G4ImportanceAlgorithm.hh
• G4ImportanceAlgorithm.cc

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