/data/refman/pasoursint/CMSSW_5_2_7_hltpatch1/src/FastSimulation/Utilities/interface/LandauFluctuationGenerator.h

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#ifndef FastSimulation_Utilities_LandauFluctuationGenerator_H
#define FastSimulation_Utilities_LandauFluctuationGenerator_H

#include "FastSimulation/Utilities/interface/BaseNumericalRandomGenerator.h"

#include <cmath>

class RandomEngine;

class LandauFluctuationGenerator : public BaseNumericalRandomGenerator
{
 public:

  LandauFluctuationGenerator(const RandomEngine* engine) : 
    BaseNumericalRandomGenerator(engine,-3.5,25.) {
    initialize();
  }

  virtual ~LandauFluctuationGenerator() {}

  double landau() const { return generate(); }
  
  virtual double function(double x) { return ersatzt(x); }

 private:

  double ersatzt(double x) { 
    return  std::exp(-0.5 * ( x + std::exp(-x) )) / std::sqrt (2. *M_PI); 
  }
};
#endif