G4LowEXsection.cc

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#include <cmath>
#include "G4Exp.hh"
#include "G4Log.hh"
#include "G4LowEXsection.hh"
#include "G4SystemOfUnits.hh"

G4double G4LowEXsection::
 CrossSection(G4double aX) const
 {
   G4double result = 0;
   if(aX<front().first) return 0;
   G4LowEXsection::const_iterator i;
   G4LowEXsection::const_iterator it=end();
   for(i=begin(); i!=end(); i++)
   {
     if((*i).first/MeV>aX) break;
     it = i;
   }
   G4double x1 = G4Log((*it).first);
   G4double x2 = G4Log((*(it+1)).first);
   G4double y1 = G4Log((*it).second);
   G4double y2 = G4Log((*(it+1)).second);
   G4double x = G4Log(aX);
   G4double y = y1+(x-x1)*(y2-y1)/(x2-x1);
   result = G4Exp(y);
   return result*millibarn;
 }