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// $Id: G4CrossSectionExcitationBornPartial.cc,v 1.4 2009/06/10 13:32:36 mantero Exp $
// GEANT4 tag $Name: geant4-09-03 $

#include "G4CrossSectionExcitationBornPartial.hh"

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

G4CrossSectionExcitationBornPartial::G4CrossSectionExcitationBornPartial()
{
  table = 0;
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

G4CrossSectionExcitationBornPartial::~G4CrossSectionExcitationBornPartial()
{
  delete table;
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

G4int G4CrossSectionExcitationBornPartial::RandomSelect(G4double k)
{   
  G4int level = 0;

  if (table == 0)
  {
    table = new G4DNACrossSectionDataSet(new G4LogLogInterpolation, eV,(1e-22/3.343)*m*m );
    table->LoadData("dna/sigma_excitation_p_born");
  }

  G4double* valuesBuffer = new G4double[table->NumberOfComponents()];

  const size_t n(table->NumberOfComponents());
  size_t i(n);
  G4double value = 0.;
  
  while (i>0)
  { 
    i--;
    valuesBuffer[i] = table->GetComponent(i)->FindValue(k);
    value += valuesBuffer[i];
  }
  
  value *= G4UniformRand();
  
  i = n;
  
  while (i > 0)
  {
    i--;
      
    if (valuesBuffer[i] > value)
    {
      delete[] valuesBuffer;
      return i;
    }
      value -= valuesBuffer[i];
  }

  if (valuesBuffer) delete[] valuesBuffer;

  return level;
}

