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// $Id: GVFlashShowerParameterisation.cc 69000 2013-04-15 09:24:35Z gcosmo $
//
//
// ------------------------------------------------------------
// GEANT 4 class implementation
//
//      ------- GVFlashShowerParameterisation -------
//
// Authors: Joanna Weng - 11.2005
// ------------------------------------------------------------

#include <cmath>

#include "GVFlashShowerParameterisation.hh"

#include "G4PhysicalConstants.hh"
#include "G4SystemOfUnits.hh"
#include "Randomize.hh"
#include "G4ios.hh"
#include "G4Material.hh"
#include "Gamma.hh" // @@@@
#include "G4MaterialTable.hh"

GVFlashShowerParameterisation::GVFlashShowerParameterisation()
  : thePar(0), density(0.), A(0.), Z(0.), X0(0.), Ec(0.), Rm(0.), NSpot(0.)
{
}

GVFlashShowerParameterisation::~GVFlashShowerParameterisation()
{
}

G4double GVFlashShowerParameterisation::GetEffZ(const G4Material * mat  )
{
  // Returns Z or effective Z=sum(pi*Zi) (if compound/mixture)
  // of given material
  //
  G4double z = 0.;
  G4int nofElements = mat->GetNumberOfElements();
  if (nofElements > 1) 
  {
    for (G4int i=0; i<nofElements; i++) {
      G4double zOfElement = mat->GetElement(i)->GetZ();
      G4double massFraction = mat->GetFractionVector()[i];
      // cout << mat->GetElement(i)->GetName()
      //      <<" Z= "<<zOfElement << " , Fraction= "<<massFraction <<endl;
      z += zOfElement*massFraction;
    }
  }
  else { 
    z = mat->GetZ(); 
  }  
  return z;
}

G4double GVFlashShowerParameterisation::GetEffA  (const G4Material * mat  )
{
  // Returns A or effective A=sum(pi*Ai) (if compound/mixture)
  // of given material
  //
  G4double a = 0.;
  G4int nofElements = mat->GetNumberOfElements();
  if (nofElements > 1) {
    for (G4int i=0; i<nofElements; i++) {
      G4double aOfElement = mat->GetElement(i)->GetA()/(g/mole);
      G4double massFraction = mat->GetFractionVector()[i];     
      a += aOfElement*massFraction;
    }
  }
  else { 
    a = mat->GetA()/(g/mole);
  }
  return a;
}

void GVFlashShowerParameterisation::PrintMaterial(const G4Material * mat)
{
  G4cout<<"/********************************************/ " << G4endl;
  G4cout<<"  - GVFlashShowerParameterisation::Material -  " << G4endl;
  G4cout<<"        Material : " << mat->GetName()  << G4endl;
  G4cout<<"   Z = "<< Z  << G4endl;
  G4cout<<"   A = "<< A  << G4endl;
  G4cout<<"   X0 = "<<X0/cm <<" cm" << G4endl;
  G4cout<<"    Rm= "<<Rm/cm <<" cm" << G4endl;
  G4cout<<"   Ec = "<<Ec/MeV << " MeV"<< G4endl;
  G4cout<<"/********************************************/ " << G4endl; 
}

G4double GVFlashShowerParameterisation::GeneratePhi()
{
  G4double Phi = twopi*G4UniformRand() ;
  return Phi;
}

G4double GVFlashShowerParameterisation::gam(G4double x, G4double a) const 
{
  static MyGamma theG;
  return theG.Gamma(a, x); 
}